Publications by authors named "George L Adams"

54 Publications

Comparison of angiographic and intravascular ultrasound vessel measurements in infra-popliteal endovascular interventions: The below-the-knee calibration study.

Cardiovasc Revasc Med 2021 Sep 16. Epub 2021 Sep 16.

Cardiology, NC Heart and Vascular Research, LLC, UNC School of Medicine, Raleigh, NC, USA. Electronic address:

Background: Endovascular revascularization (ER) via percutaneous transluminal angioplasty (PTA) and stenting are viable options for revascularization in below-the-knee (BTK) peripheral arterial disease. Two-dimensional angiography has been the standard of practice for estimating vessel size and selecting treatment devices during ER. However, in other vascular territories, intravascular ultrasound (IVUS) offers better visualization of the lumen dimensions.

Purpose: To compare angiographic and intravascular ultrasound reference vessel (lumen) measurements in below-the-knee peripheral artery interventions.

Methods: 20 consecutive patients were enrolled in the BTK Calibration study from 2 sites in the United States and Australia. Patients with at least one diseased segment in a native infra-popliteal artery (below-the-knee) and a clinical indication for endovascular therapy (EVT) were included with no limitations with regards to vessel diameter or lesion length. Digital subtraction angiography and intravascular ultrasound imaging were collected pre-and post-percutaneous transluminal angioplasty and images were sent to an independent Core lab for standardized quantitative analysis of the normal-looking reference vessel dimensions when available. The results were presented as least square means with 95% confidence intervals and a p-value of <0.05 was considered as significant.

Results: The overall (N = 19) mean reference vessel diameter for QVA was 2.98 ± 1.24 vs. 3.47 ± 0.72 for IVUS (mean difference was -0.50, (95% CI: -0.80, -0.20; p = 0.14). As expected in the proximal segments (N = 12), the mean reference vessel diameters were larger: for QVA was 3.17 ± 1.34 vs. 3.55 ± 0.76 in IVUS, (mean difference was -0.38, (95% CI:-0.79,0.03; p = 0.40); while in the distal segments (N = 7), mean reference vessel diameters were smaller: for QVA was 2.64 ± 1.06 vs. 3.33 ± 0.67 in IVUS, (mean difference was -0.69, (95% CI:-1.04,-0.34; p = 0.17). We observed a greater degree of acute gain in cases where the treatment balloon size correlated with the IVUS measured reference size.

Conclusion: Angiography underestimates infrapopliteal reference vessel lumen size even when quantitatively assessed. Adjunctive IVUS imaging use in guiding BTK procedures could help ensure adequate sizing and possibly impact immediate post-procedure indices.
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http://dx.doi.org/10.1016/j.carrev.2021.09.004DOI Listing
September 2021

Two-year PAD-related health care costs in patients undergoing lower extremity endovascular revascularization: results from the LIBERTY 360° trial.

J Med Econ 2021 Jan-Dec;24(1):570-580

University of Missouri - Kansas City School of Medicine, Kansas City, MO, USA.

Background: Multiple studies have demonstrated the high economic burden related to the management of lower extremity peripheral artery disease (PAD). This is the first study to examine long-term PAD-related costs among unselected patients undergoing endovascular intervention, and to investigate how clinical and anatomic factors impact cost outcomes over time.

Methods And Results: We performed a prospective health economic study alongside the LIBERTY 360° trial (ClinicalTrials.gov; identifier NCT01855412) - a prospective, multi-center study evaluating the long-term outcomes of endovascular revascularization to treat claudication or critical limb ischemia. Costs (2018) were calculated using a combination of standard "bottom-up" cost accounting methods (for index procedures), itemized hospital charges and department level cost-to-charge ratios (for non-procedural hospital resources), national Medicare Severity-Diagnosis Related Group-specific average reimbursements (for follow-up hospitalizations) and Medicare payments (for outpatient/chronic care). Methods for the analysis of censored cost data were used to adjust cost estimates for patients with incomplete follow-up. Independent predictors of cumulative 2-year costs were explored using generalized linear models. A total of 1,189 patients were included (500 Rutherford 2-3, 589 Rutherford 4-5, 100 Rutherford 6). Mean total costs associated with the index procedure hospitalization increased with Rutherford classification ($10,304, $11,418, and $19,403 for Rutherford 2-3, 4-5, and 6, respectively;  < 0.01 in all pairwise comparisons). Mean total 2-year follow-up costs were $11,416, $24,846, and $25,720 for Rutherford 2-3, 4-5, and 6, respectively ( < 0.001 comparing Rutherford 2-3 to the other 2 groups;  = 0.09 comparing Rutherford 4-5 and Rutherford 6). Key predictors of higher cumulative 2-year costs included female sex, pedal lesion location, severe lesion calcification, the presence of one or more chronic total occlusions, the number of wounds present on the target limb at baseline, and Rutherford classification.

Conclusions: Among patients with symptomatic lower extremity PAD undergoing endovascular revascularization, initial treatment costs and total 2-year costs vary significantly according to clinical and lesion-level characteristics, as well as symptom burden.
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http://dx.doi.org/10.1080/13696998.2021.1917141DOI Listing
September 2021

Characteristics and Outcomes of Patients With Diabetes Mellitus Undergoing Peripheral Vascular Intervention for Infrainguinal Symptomatic Peripheral Artery Disease.

Vasc Endovascular Surg 2021 Feb 23;55(2):124-134. Epub 2020 Oct 23.

Division of Cardiology, 3065Duke University Health System, Durham, NC, USA.

Purpose: Patients with diabetes mellitus (DM) are known to be at higher risk for peripheral artery disease (PAD), amputations, and major adverse cardiovascular events, though it is unclear whether they are at any higher risk for repeat intervention. LIBERTY 360 offered an opportunity to study a real-world cohort of patients who underwent distal superficial femoral artery endovascular revascularizations. We aimed to describe patients with DM, their outcomes following peripheral vascular intervention, and the effect of DM on outcomes in the LIBERTY 360 cohort.

Methods: LIBERTY 360 is a prospective, multi-center, non-randomized, mono-industry funded observational study of patients undergoing endovascular revascularization. Outcomes included 30-day and 1-year all-cause mortality, major amputation, target vessel/lesion revascularization, and a composite of those events. A multivariable regression model including DM was constructed to examine the effect of DM on outcomes. Multivariable survival estimates were made using Cox proportional hazards models.

Results: A total of 1,204 patients were enrolled, of whom 727 had DM (60.4%). Patients with DM had significantly more comorbidities and a third required insulin for DM management. Patients with DM had more severe disease based on Rutherford classification at baseline. After adjusting for comorbidities and disease severity, DM patients had more frequent major amputations at 1 year (5.2% versus 1.2%; HR 2.71, 95%CI 1.05-6.98, p = 0.040). The 1-year rates of all-cause mortality and target vessel/lesion revascularization were not significantly higher for patients with DM.

Conclusions: Diabetes mellitus was associated with increased major amputations at 1 year following endovascular revascularization after accounting for demographics, comorbidities, and PAD-related characteristics. Further research is needed to determine which aspects of PAD and DM are most strongly associated with poor outcomes following lower extremity revascularization.
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http://dx.doi.org/10.1177/1538574420968671DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8150867PMC
February 2021

The impact of chronic kidney disease on outcomes following peripheral vascular intervention.

Clin Cardiol 2020 Nov 11;43(11):1308-1316. Epub 2020 Aug 11.

Division of Cardiology, Department of Medicine, Duke University Health System, Durham, North Carolina, USA.

Background: Patients with chronic kidney disease (CKD) have worsened clinical outcomes following percutaneous coronary intervention; however, limited evidence exists in patients undergoing peripheral vascular intervention (PVI).

Purpose: We aimed to assess the effect of CKD on outcomes following PVI for symptomatic peripheral artery disease.

Methods: Using patients from the LIBERTY 360 study, we compared the rates of 30 day and 1 year major adverse vascular events (MAVE), a composite of all-cause mortality, major amputation, and target vessel/lesion revascularization, between patients with and without CKD (estimated glomular filtration rate less than 60) following PVI. Multivariable adjustment was performed to assess for independent association between CKD and outcomes.

Results: Among 1189 patients enrolled, 378 patients (31.8%) had CKD. At 1 year, patients with CKD had higher rates of MAVE (34.6% vs 25.6%), all-cause mortality (11.9% vs 5.5%), and major amputation (5.9% vs 2.6%) when compared with patients without CKD (all P < .05). After adjustment, patients with CKD had higher risks of 1-year MAVE (HR 1.30, 95% CI 1.04-1.64; P = .023) and all-cause mortality (HR 1.88, 95% CI 1.22-2.91; P = .005) when compared with patients without CKD. There was no statistically significant difference in risk of major amputations (HR 1.70, 95% CI 0.91-3.17; P = .094).

Conclusions: Despite high procedural success and low amputation rates, patients with CKD remain at greater risk for MAVE and all-cause mortality after PVI. Further research is needed to determine treatment strategies to mitigate substantial mortality risk in this vulnerable population.
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http://dx.doi.org/10.1002/clc.23444DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7661640PMC
November 2020

Sex-Related Differences in the Outcomes of Endovascular Interventions for Chronic Limb-Threatening Ischemia: Results from the LIBERTY 360 Study.

Vasc Health Risk Manag 2020 8;16:271-284. Epub 2020 Jul 8.

Division of Cardiology, Rocky Mountain Regional VA Medical Center, University of Colorado, Denver, CO, USA.

Introduction: Previous studies have suggested that women with chroniclimb-threatening ischemia (CLTI) may have worse outcomes than men. The aim of this study was to determine whether there are sex-related differences in outcomes of patients with CLTI undergoing endovascular treatment with current endovascular technologies.

Patients And Methods: Data were derived from the LIBERTY 360 study (NCT01855412). Hazard ratios and the respective 95% confidence intervals were synthesized to examine the association between sex and all-cause mortality, target vessel revascularization (TVR), major amputation, major adverse event (MAE) and major amputation/death up to 3 years of follow-up.

Results: A total of 689 patients with CLTI (female: N=252 vs male: N=437) treated with any FDA approved or cleared device were included. The mean lesion length was 126.9±117.3mm and 127.4±113.3mm for the female and male patients, respectively. Although a slightly higher incidence of in-hospital mortality was observed in the female group (1.2% vs 0.0%, p=0.049), there was no difference in female vs male survival rates during follow-up. However, the risk of major amputation at 18 months was higher for the male group (male vs female: HR: 2.36; 95% CI: 1.09-5.12; p=0.030). No difference between the two groups was detected in terms of TVR or MAE during follow-up.

Discussion: Data regarding sex-related disparity in outcomes after endovascular therapy of patients with CLTI are conflicting. Gender-related characteristics rather than biological sex characteristics might be the cause of these conflicting findings. Further studies are needed to evaluate the role of sex in revascularization outcomes among this high-risk population.
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http://dx.doi.org/10.2147/VHRM.S246528DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7354949PMC
September 2020

One-Year Outcomes of Peripheral Endovascular Device Intervention in Critical Limb Ischemia Patients: Sub-Analysis of the LIBERTY 360 Study.

Vasc Health Risk Manag 2020 10;16:57-66. Epub 2020 Feb 10.

North Carolina Heart and Vascular, Rex Hospital, UNC School of Medicine, Raleigh, NC, USA.

Background: High-risk patients with advanced peripheral artery disease (PAD), including critical limb ischemia (CLI), are often excluded from peripheral endovascular device intervention clinical trials, leading to difficulty in translating trial results into real-world practice. There is a need for prospectively assessed studies to evaluate peripheral endovascular device intervention outcomes in CLI patients.

Methods: LIBERTY 360 is a prospective, observational, multi-center study designed to evaluate the procedural and long-term clinical outcomes of peripheral endovascular device intervention in real-world patients with symptomatic lower-extremity PAD. One thousand two hundred and four patients were enrolled and stratified based on Rutherford Classification (RC): RC2-3 (N=501), RC4-5 (N=603), and RC6 (N=100). For this sub-analysis, RC5 and RC6 patients (RC5-6; N=404) were pooled and 1-year outcomes were assessed.

Results: Procedural complications rarely (1.7%) resulted in post-procedural hospitalization and 89.1% of RC5-6 patients were discharged to home. Considering the advanced disease state in RC5-6 patients, there was a high freedom from 1-year major adverse event rate of 65.5% (defined as target vessel revascularization, death to 30 days, and major target limb amputation). At 1 year, freedom from major amputation was 89.6%. Wounds identified at baseline on the target limb had completely healed in 172/243 (70.8%) of the RC5-6 subjects by 1 year. Additionally, the overall quality of life, as measured by VascuQoL, improved from baseline to 1 year.

Conclusion: LIBERTY investigated real-world PAD patients with independent oversight of outcomes. This analysis of LIBERTY RC5-6 patients demonstrates that peripheral endovascular device intervention can be successful in CLI patients, with low rates of major amputation and improvement in wound healing and quality of life through 1-year follow-up.LIBERTY 360, https://clinicaltrials.gov/ct2/show/NCT01855412, ClinicalTrials.gov Identifier: NCT01855412.
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http://dx.doi.org/10.2147/VHRM.S230934DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7020930PMC
March 2020

Novel Mechanical Thrombectomy Device for the Treatment of Acute Myocardial Infarction: A Retrospective Report of Initial Results.

J Invasive Cardiol 2020 04 5;32(4):142-146. Epub 2020 Feb 5.

1UNC REX Healthcare, 400 Health Park Drive, Raleigh, NC 27607 USA.

Objective: The objective of this study was to assess the effectiveness of mechanical thrombectomy using the Aspire mechanical thrombectomy device (Control Medical) for the treatment of acute myocardial infarction (AMI) as measured by Thrombolysis in Myocardial Infarction (TIMI) flow post procedure compared with baseline.

Methods: This is a retrospective study for the treatment of acute myocardial infarction (AMI) in ST-segment elevation myocardial infarction (STEMI) and non-ST segment elevation myocardial infarction (NSTEMI) patients. The study was approved by an independent ethical review board. Data were collected retrospectively from 48 subjects at three study sites. The primary endpoint was TIMI flow post thrombectomy compared with baseline. The safety endpoint was 30-day major adverse cardiac event, defined as death, MI, and target-vessel revascularization (TVR). Eligibility criteria included AMI patients ages 18-90 years who had previous treatment with the Aspire mechanical thrombectomy device, preprocedure TIMI flow 0 to 2, and ability to tolerate antiplatelet therapy.

Results: Of the 48 subjects, 81.2% were male, 33.3% were diabetics, 64.6% were hypertensive, 52.1% had hyperlipidemia, and 85.4% had STEMI, with 38.0% anterior and 56.0% inferior AMI. Baseline TIMI flow was 0-1 in 89.6% of subjects. Post-thrombectomy TIMI flow 2-3 was achieved in 85.4% and all subjects had TIMI flow 3 at the end of the intervention. The device did not track in 1 patient and was not used. There were 5 deaths (10.4%), all unrelated to the aspiration thrombectomy procedure, and 0% experienced a stroke.

Conclusion: The Aspire mechanical thrombectomy device demonstrated initial effectiveness and safety. Further prospective studies using objective performance criteria to demonstrate effectiveness and safety using the Aspire mechanical thrombectomy device are necessary to determine whether short-term and long-term outcomes improve over previously published clinical trials.
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April 2020

One-Year Results of the LIBERTY 360 Study: Evaluation of Acute and Midterm Clinical Outcomes of Peripheral Endovascular Device Interventions.

J Endovasc Ther 2019 04 6;26(2):143-154. Epub 2019 Feb 6.

8 Harvard Medical School, Boston, MA, USA.

Purpose: To report the 1-year results of a multicenter study of peripheral artery disease (PAD) treatment with a variety of endovascular treatment strategies employed in routine practice.

Materials And Methods: The LIBERTY trial ( ClinicalTrials.gov identifier NCT01855412) is a prospective, observational, core laboratory-assessed, multicenter study of endovascular device intervention in 1204 subjects (mean age 69.8±10.7 years; 770 men) stratified by Rutherford category (RC): claudicants (RC2,3; n=501) and critical limb ischemia (CLI) with no/minimal tissue loss (RC4,5; n=603) or significant tissue loss (RC6; n=100). Key outcomes included quality of life (QoL) measures (VascuQol and EuroQol) and freedom from major adverse events (MAE), defined as death (within 30 days), major amputation, and target vessel revascularization based on Kaplan-Meier analysis.

Results: Successful revascularization was beneficial, with RC improvement noted across all groups. Thirty-day freedom from MAE estimates were high across all groups: 99.2% in RC2,3, 96.1% in RC4,5, and 90.8% in RC6. At 12 months, the freedom from MAE was 82.6% in RC2,3, 73.2% in RC4,5, and 59.3% in RC6 patients. Estimates for freedom from major amputation at 12 months were 99.3%, 96.0%, and 81.7%, respectively. QoL scores improved significantly across all domains in all groups with 12-month VascuQol total scores of 5.3, 5.0, and 4.8 for RC2,3, RC4,5, and RC6, respectively.

Conclusion: The results indicate that peripheral endovascular intervention is a viable treatment option for RC2,3, RC4,5, and RC6 patients as evidenced by the high freedom from major amputation, as well as the improvement in QoL and the RC at 12 months. Furthermore, primary unplanned amputation is often not necessary in RC6.
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http://dx.doi.org/10.1177/1526602819827295DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6431778PMC
April 2019

Orbital atherectomy for calcified femoropopliteal lesions: a current review.

J Cardiovasc Surg (Torino) 2019 Apr 28;60(2):212-220. Epub 2019 Jan 28.

Advanced Cardiac and Vascular Amputation Prevention Centers, Michigan State University, School of Medicine, Grand Rapids, MI, USA.

The orbital atherectomy system is a novel form of atherectomy that uses orbital sanding and pulsatile forces, an effective method of treatment for peripheral atherosclerotic lesions with varying levels of occlusion. Although the devices only has a general indication from the FDA to treat atherosclerotic lesions, they are effective in treating all kinds of lesions, and can therefore mitigate effects of all severities of peripheral artery disease. This approach to endovascular therapy involves the use of differential sanding to preferentially ablate fibrous, fibrofatty and calcified lesions, while deflecting healthy intima away from the crown. The eccentrically mounted crown design allows the device to employ rhythmic pulsating forces that penetrate the medial layer, and cause cracking in the lesions in order to facilitate easier balloon inflation and intravascular drug elution. The combination of vessel modification and lumen enlargement through sanding can effectively restore blood flow to the extremities, and can eliminate risk of critical limb ischemia, as well as subsequent amputation. Extensive lab testing and clinical trials have confirmed the high success rates and low major adverse events associated with this form of treatment. The device is economically viable as well, since its cost is offset by the lower frequency of adjunctive therapy sessions when compared to other devices. Considering the results outlined in this manuscript, the Diamondback 360° is an effective form of atherectomy therapy for peripheral artery disease. In-depth understanding of the operation preparation, procedure, and best imaging techniques can help to optimize outcomes.
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http://dx.doi.org/10.23736/S0021-9509.19.10879-8DOI Listing
April 2019

Utility of a Power Aspiration-Based Extraction Technique as an Initial and Secondary Approach in the Treatment of Peripheral Arterial Thromboembolism: Results of the Multicenter PRISM Trial.

J Vasc Interv Radiol 2018 Jan 9;29(1):92-100. Epub 2017 Nov 9.

VIR Chicago, Hinsdale, Illinois.

Purpose: To investigate the safety and initial efficacy of XTRACT, a power aspiration-based extraction technique for treatment of peripheral arterial thromboembolism with the use of the Penumbra/Indigo system.

Materials And Methods: A total of 79 patients were enrolled: 39 (49.4%) underwent XTRACT as the initial therapy and 40 (50.6%) underwent XTRACT after failed catheter-directed thrombolysis or other mechanical intervention or for removal of distal emboli that occurred during an intervention. Occlusion locations were as follows: 36.7% (n = 29) in the profunda, common, or superficial femoral artery; 35.4% (n = 28) in the popliteal artery; 15.2% (n = 12) in the tibial artery; 7.6% (n = 6) in the peroneal artery; and the remainder in the common iliac (n = 1), external iliac (n = 1), sciatic (n = 1), and brachial (n = 1) arteries.

Results: Complete or near-complete revascularization (Thrombolysis In Myocardial Infarction [TIMI] grade 2/3 flow) was achieved in 87.2% of patients (68 of 78) immediately after the XTRACT procedure and before any other intervention. Successful revascularization was achieved in 79.5% of patients (31 of 39) as an initial treatment and in 92.5% (37 of 40) as salvage or secondary therapy. After additional adjunctive endovascular interventions, TIMI grade 2/3 flow was achieved in 96.2% of patients (76 of 79). Complete thrombus removal and restoration of normal flow (TIMI grade 3) was achieved in 77.2% of patients (61 of 79) after all endovascular treatment was completed. No patients required surgical revascularization. No device-related adverse events occurred.

Conclusions: XTRACT was safe and effective for revascularization of acute or subacute peripheral arterial occlusions as a primary therapy or as a secondary therapy after other endovascular techniques had failed.
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http://dx.doi.org/10.1016/j.jvir.2017.08.019DOI Listing
January 2018

Double-blind, randomized phase 3 trial of low-dose 13-cis retinoic acid in the prevention of second primaries in head and neck cancer: Long-term follow-up of a trial of the Eastern Cooperative Oncology Group-ACRIN Cancer Research Group (C0590).

Cancer 2017 Dec 7;123(23):4653-4662. Epub 2017 Aug 7.

Department of Medicine Hematology/Oncology, University of Rochester Medical Center, Rochester, New York.

Background: 13-Cis retinoic acid (13-CRA) is a synthetic vitamin A derivative. High-dose 13-CRA in patients with squamous cell cancers of the head and neck (SCCHNs) reduces the incidence of second primary tumors (SPTs). The authors report long-term results from a phase 3 randomized trial that compared treatment with low-dose 13-CRA versus placebo for patients who had early stage SCCHN, with a focus on the development of SPTs and overall survival (OS).

Methods: In total, 176 patients who received treatment for stage I/II SCCHN were randomized to receive either low-dose 13-CRA (weight-based dose of 7.5 mg or 10 mg) or placebo for 2 years. A competing-risk approach and the log-rank test were used to compare the time to SPT and OS, respectively, between groups.

Results: 13-CRA neither significantly reduced the cumulative incidence of SPT (P = .61) nor improved the time to SPT (hazard ratio [HR] for 13-CRA/placebo; 0.86; P = .61). Despite limited power, there was a trend toward improved OS for the 13-CRA arm (HR, 0.75; P = .14), particularly among patients whose index tumor was surgically excised (N = 26; HR, 0.50; P = .057) and among women (N = 39; HR, 0.44; P = .065) and never/former smokers (N = 129; HR, 0.61; P = .055), with a median follow-up of 16 years. The main 13-CRA related toxicities were dry skin and cheilitis.

Conclusions: Treatment with low-dose 13-CRA for 2 years did not decrease the incidence of SPT; subset analysis indicates a potential survival advantage among patients who are women and never/former smokers. More targeted interventions based on clinical risk factors and molecular characterization of tumors may yield greater success in future prevention trials. Cancer 2017;123:4653-4662. © 2017 American Cancer Society.
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http://dx.doi.org/10.1002/cncr.30920DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5693641PMC
December 2017

Tibiopedal Access for Crossing of Infrainguinal Artery Occlusions: A Prospective Multicenter Observational Study.

J Endovasc Ther 2016 12 24;23(6):839-846. Epub 2016 Aug 24.

University of North Carolina, Rex Hospital, Raleigh, NC, USA.

Purpose: To report a prospective, multicenter, observational study (ClinicalTrials.gov identifier NCT01609621) of the safety and effectiveness of tibiopedal access and retrograde crossing in the treatment of infrainguinal chronic total occlusions (CTOs).

Methods: Twelve sites around the world prospectively enrolled 197 patients (mean age 71±11 years, range 41-93; 129 men) from May 2012 to July 2013 who met the inclusion criterion of at least one CTO for which a retrograde crossing procedure was planned or became necessary. The population consisted of 64 (32.5%) claudicants (Rutherford categories 2/3) and 133 (67.5%) patients with critical limb ischemia (Rutherford category ≥4). A primary antegrade attempt to cross had been made prior to the tibiopedal attempt in 132 (67.0%) cases. Techniques used for access, retrograde lesion crossing, and treatment were at the operator's discretion. Follow-up data were obtained 30 days after the procedure.

Results: Technical tibiopedal access success was achieved in 184 (93.4%) of 197 patients and technical occlusion crossing success in 157 (85.3%) of the 184 successful tibial accesses. Failed access attempts were more common in women (9 of 13 failures). The rate of successful crossing was roughly equivalent between sexes [84.7% (50/59) women compared to 85.6% (107/125) men]. Technical success did not differ significantly based on a prior failed antegrade attempt: the access success rate was 92.4% (122/132) after a failed antegrade access vs 95.4% (62/65) in those with a primary tibiopedal attempt (p=0.55). Similarly, crossing success was achieved in 82.8% (101/122) after a failed antegrade access vs 90.3% (56/62) for patients with no prior antegrade attempt (p=0.19). Minor complications related to the access site occurred in 11 (5.6%) cases; no patient had access vessel thrombosis, compartment syndrome, or surgical revascularization.

Conclusion: Tibiopedal access appears to be safe and can be used effectively for the crossing of infrainguinal lesions in patients with severe lower limb ischemia.
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http://dx.doi.org/10.1177/1526602816664768DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5315197PMC
December 2016

The LIBERTY study: Design of a prospective, observational, multicenter trial to evaluate the acute and long-term clinical and economic outcomes of real-world endovascular device interventions in treating peripheral artery disease.

Am Heart J 2016 Apr 30;174:14-21. Epub 2015 Dec 30.

Massachusetts General Hospital, Boston, MA. Electronic address:

Background: Most peripheral artery disease (PAD) clinical device trials are supported by commercial manufacturers and designed for regulatory device approval, with extensive inclusion/exclusion criteria to support homogeneous patient populations. High-risk patients with advanced disease, including critical limb ischemia (CLI), are often excluded leading to difficulty in translating trial results into real-world clinical practice. As a result, physicians have no direct guidance regarding the use of endovascular devices. There is a need for objectively assessed studies to evaluate clinical, functional, and economic outcomes in PAD patient populations.

Study Design: LIBERTY is a prospective, observational, multicenter study sponsored by Cardiovascular Systems Inc (St Paul, MN) to evaluate procedural and long-term clinical and economic outcomes of endovascular device interventions in patients with symptomatic lower extremity PAD. Approximately 1,200 patients will be enrolled and followed up to 5 years: 500 patients in the "Claudicant Rutherford 2-3" arm, 600 in the "CLI Rutherford 4-5" arm, and 100 in the "CLI Rutherford 6" arm. The study will use 4 core laboratories for independent analysis and will evaluate the following: procedural and lesion success, rates of major adverse events, duplex ultrasound interpretations, wound status, quality of life, 6-minute walk test, and economic analysis. The LIBERTY Patient Risk Score(s) will be developed as a clinical predictor of outcomes to provide guidance for interventions in this patient population.

Conclusion: LIBERTY will investigate real-world PAD patients treated with endovascular revascularization with rigorous study guidelines and independent oversight of outcomes. This study will provide observational, all-comer patient clinical data to guide future endovascular therapy.
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http://dx.doi.org/10.1016/j.ahj.2015.12.013DOI Listing
April 2016

Impact of lesion location on procedural and acute angiographic outcomes in patients with critical limb ischemia treated for peripheral artery disease with orbital atherectomy: A CONFIRM registries subanalysis.

Catheter Cardiovasc Interv 2016 Feb 9;87(3):440-5. Epub 2015 Dec 9.

Rex Healthcare, Raleigh, NC.

Objectives: This analysis compares the procedural and acute angiographic outcomes in patients with critical limb ischemia (CLI) treated with orbital atherectomy in above-the-knee (ATK)/popliteal (POP) lesions versus below-the-knee (BTK) lesions.

Background: Lesion location affects the procedural outcomes and the opportunity for limb salvage in patients with CLI suffering from peripheral artery disease (PAD).

Methods: The CONFIRM registry series was analyzed and includes 1109 real-world patients (1544 lesions) suffering from CLI treated with orbital atherectomy. The rates of dissection, perforation, slow flow, vessel closure, spasm, embolism, and thrombus formation were compared between CLI patients with ATK/POP lesions and BTK lesions.

Results: Patients with ATK/POP lesions had a higher final residual stenosis (10 vs. 9%; P = 0.004) and use of more adjunctive therapies (e.g. balloons and stents; 1.3 vs. 1.1%; P < 0.001) compared to patients with BTK lesions. Patients with BTK had higher incidence of perforation (1.5 vs. 0.2%; P = 0.005), slow flow (7.7 vs. 5.0%; P = 0.03) and spasm (10.3 vs. 4.2%; P < 0.001) but lower incidence of embolism (0.4 vs. 5.1%; P < 0.001).

Conclusions: Plaque modification with orbital atherectomy was successful in CLI patients regardless of lesion location. BTK lesions were associated with increased rates of perforation, slow flow and spasm which may be explained by more challenging procedural characteristics in these patients such as smaller vessel size and tortuosity. The higher incidence of emboli in ATK/POP lesions is most likely attributed to the higher prevalence of severe calcium observed in this cohort.
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http://dx.doi.org/10.1002/ccd.26349DOI Listing
February 2016

Subanalysis of the CONFIRM Registries: Acute Procedural Outcomes in Claudicant and Critical Limb Ischemia Patients With Varying Levels of Calcification Treated for Peripheral Arterial Disease With Orbital Atherectomy.

J Invasive Cardiol 2015 Nov;27(11):516-20

Rex Healthcare, 4414 Lake Boone Trail, Suite 402, Raleigh, NC 27607 USA.

Purpose: Patients with peripheral arterial disease (PAD) can be classified into groups based upon the severity of the disease using the Rutherford classification system. This analysis compares the procedural outcomes of PAD patients treated with orbital atherectomy stratified by Rutherford class (1-3 = intermittent claudication; 4-6 = critical limb ischemia [CLI]), and acute angiographic outcomes of these patients stratified by degree of lesion calcification.

Methods: The CONFIRM registry series was analyzed and included 1697 patients with intermittent claudication (Rutherford class 1-3) and 1320 patients with CLI (Rutherford class 4-6) treated with orbital atherectomy. The composite rate of dissection, perforation, slow-flow, vessel closure, spasm, embolism, and thrombus formation was compared between claudicants and CLI patients with varying degrees of lesion calcification.

Results: Patients with CLI were older and had a higher prevalence of diabetes, coronary artery disease, and renal disease (P<.001). Claudicants with moderately/severely calcified lesions had a lower rate of dissection (both non-flow limiting and flow-limiting) than claudicants with mildly/minimally calcified lesions. CLI patients with mildly/minimally calcified lesions had higher rates of embolism and thrombus than CLI patients with moderately/severely calcified lesions.

Conclusions: Plaque modification with orbital atherectomy resulted in similar low procedural complication rates in the CLI group compared with the claudicant group. These results suggest that orbital atherectomy is safe and effective for treating calcified lesions in high-risk patients with varying severity of PAD symptoms.
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November 2015

Impact of Advanced Age on Procedural and Acute Angiographic Outcomes in Patients Treated for Peripheral Artery Disease With Orbital Atherectomy: A CONFIRM Registries Subanalysis.

J Invasive Cardiol 2015 Aug;27(8):381-6

Departments of Medicine and Cardiology, UCLA Medical Center, Los Angeles, California, USA.

Purpose: Data on the outcomes of elderly patients with peripheral arterial disease (PAD) who undergo orbital atherectomy are limited. This analysis compares the procedural and acute angiographic outcomes of PAD patients treated with orbital atherectomy stratified by age (≥ 75 years of age [elderly] vs <75 years of age [younger]).

Methods: The CONFIRM registry series with non-missing age was analyzed and included 2995 real-world PAD patients (4557 lesions) with 1753 younger patients (2637 lesions) and 1242 elderly patients (1920 lesions) treated with orbital atherectomy. The composite rate of adverse events including dissection, perforation, slow flow, vessel closure, spasm, embolism, and thrombus formation was compared between groups.

Results: Elderly patients had a higher proportion of females (47.5% vs 35.3%; P<.001), more patients with critical limb ischemia (49.9% vs 39.3%; P<.001), longer lesion length (75.0 ± 74.1 mm vs 69.9 ± 68.9 mm; P=.01), and more lesions treated below the knee (38.9% vs 34.4%; P=.01). Younger and elderly patients had similar rates of composite adverse events (22.0% vs 21.3%; P=.81), dissection (11.4% vs 10.5%; P=.72), vessel closure (1.7% vs 1.1%; P=.13), spasm (6.3% vs 6.4%; P=.96), and embolism (2.5% vs 1.6%; P=.31). Elderly patients had a lower rate of thrombus formation (0.9% vs 1.6%; P=.03), but a higher perforation rate (1.2% vs 0.4%; P=.01).

Conclusions: Orbital atherectomy resulted in similar composite rates of adverse events despite the elderly having unfavorable baseline Rutherford classification and lesion characteristics. The higher rate of perforation may be explained by longer and more below-the-knee lesions.
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August 2015

Pooled analysis of the CONFIRM registries: impact of gender on procedure and angiographic outcomes in patients undergoing orbital atherectomy for peripheral artery disease.

J Endovasc Ther 2015 Feb;22(1):57-62

Rex Healthcare, Raleigh, NC, USA.

Purpose: To compare the acute procedure and angiographic outcomes of peripheral artery disease (PAD) patients treated with orbital atherectomy stratified by gender.

Methods: The CONFIRM I, II, and III registries are US multicenter, nonrandomized, all-comers registries of PAD patients who were treated with orbital atherectomy. All patients with gender specified in the registry database were included in the current analysis, which compared the final residual stenosis achieved after atherectomy and the rate of acute complications in female and male patients. The 3 registries included 3131 patients with 4761 lesions: 1261 women (mean age 73.2 ± 10.7 years) with 1874 lesions and 1870 men (mean age 70.4 ± 10.2) with 2887 lesions.

Results: The women were older (p < 0.001) and had a higher but nonsignificant prevalence of critical limb ischemia (p = 0.075). After treatment, the final residual stenosis in women vs. men was 9% ± 11% vs. 11% ± 11%, respectively (p < 0.001). Women had a higher rate of all types of dissection (13.3% vs. 9.9%, p<0.001). However, both genders had similar rates of flow-limiting dissections (1.6% vs. 1.4%, p = 0.61), perforation, slow flow, vessel closure, spasm, embolism, and thrombus formation.

Conclusion: The gender analysis of the CONFIRM registries revealed that there was successful lesion modification with orbital atherectomy in both men and women; however, women had a higher rate of dissection (all types). This difference is likely because of the older age and higher percentage of critical limb ischemia in women in this cohort. These results, however, suggest that additional studies should be completed to further understand the increased risks for women vs. men during endovascular procedures.
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http://dx.doi.org/10.1177/1526602814564367DOI Listing
February 2015

Pooled analysis of the CONFIRM Registries: outcomes in renal disease patients treated for peripheral arterial disease using orbital atherectomy.

J Invasive Cardiol 2014 Aug;26(8):350-4

UCLA Medical Center, Los Angeles, CA 90095 USA. or

Background: Patients with renal disease typically have severely calcified peripheral arterial disease. As a result, this population may have worse clinical outcomes following endovascular intervention compared to patients without renal insufficiency. Clinical trials typically exclude this patient population.

Methods: Analysis of the CONFIRM I-III registries revealed 1105 patients with renal disease (1777 lesions) and 1969 patients without renal disease (2907 lesions) who underwent orbital atherectomy. This subanalysis compared the composite procedural complication rate including dissection, perforation, slow flow, vessel closure, spasm, embolism, and thrombus formation in patients with and without renal disease.

Results: Patients with renal disease had a higher prevalence of diabetes (P<.001), hypertension (P<.001), hyperlipidemia (P<.001), and coronary artery disease (P<.001), Rutherford 5 or 6 lesions (P<.001), as well as more lesions treated (P<.001), more vessels treated (P<.001), and more below-the-knee lesions (P<.001). The renal disease and non-renal disease groups had similar composite procedural complication rates (21.3% vs. 22.4%; P=.46), dissection (11.1% vs. 11.5%; P=.83), perforation (0.6% vs. 0.8%; P=.55), slow flow (5.0% vs. 4.2%; P=.19), spasm (6.7% vs. 6.2%; P=.40), embolism (1.7% vs. 2.6%; P=.12), and thrombus formation (1.4% vs. 1.0%; P=.56). The renal disease group had a trend toward decreased vessel closure (1.1% vs. 1.6%; P=.08).

Conclusion: Plaque modification with orbital atherectomy resulted in similar low rates of procedural complications in the renal disease group compared with the non-renal disease group despite more unfavorable baseline clinical and lesion characteristics in the renal disease group.
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August 2014

Technique optimization of orbital atherectomy in calcified peripheral lesions of the lower extremities: the CONFIRM series, a prospective multicenter registry.

Catheter Cardiovasc Interv 2014 Jan 7;83(1):115-22. Epub 2013 Oct 7.

Cardiology and Interventional Vascular Associates, Dallas, Texas.

Objectives: The purpose of CONFIRM registry series was to evaluate the use of orbital atherectomy (OA) in peripheral lesions of the lower extremities, as well as optimize the technique of OA.

Background: Methods of treating calcified arteries (historically a strong predictor of treatment failure) have improved significantly over the past decade and now include minimally invasive endovascular treatments, such as OA with unique versatility in modifying calcific lesions above and below-the-knee.

Methods: Patients (3135) undergoing OA by more than 350 physicians at over 200 US institutions were enrolled on an "all-comers" basis, resulting in registries that provided site-reported patient demographics, ABI, Rutherford classification, co-morbidities, lesion characteristics, plaque morphology, device usage parameters, and procedural outcomes.

Results: Treatment with OA reduced pre-procedural stenosis from an average of 88-35%. Final residual stenosis after adjunctive treatments, typically low-pressure percutaneous transluminal angioplasty (PTA), averaged 10%. Plaque removal was most effective for severely calcified lesions and least effective for soft plaque. Shorter spin times and smaller crown sizes significantly lowered procedural complications which included slow flow (4.4%), embolism (2.2%), and spasm (6.3%), emphasizing the importance of treatment regimens that focus on plaque modification over maximizing luminal gain.

Conclusion: The OA technique optimization, which resulted in a change of device usage across the CONFIRM registry series, corresponded to a lower incidence of adverse events irrespective of calcium burden or co-morbidities.
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http://dx.doi.org/10.1002/ccd.25046DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4158859PMC
January 2014

Ultrasound-mediated oxygen delivery to lower extremity wounds.

Wounds 2012 Aug;24(8):201-6

Duke/Raleigh Hospital, Raleigh, NC.

Critical limb ischemia (CLI), an end result of peripheral ar- terial disease, remains a major clinical challenge. Wound healing in patients with CLI can be difficult due to diminished tissue oxygen- ation, often leading to recalcitrant ulcers and frequent limb loss. Nu- merous therapies, including hyperbaric oxygen therapy (HBOT), have been used to correct this regional ischemia, although often with mixed results. This case series investigates the effects of oxygen therapy de- livery augmented by low-frequency ultrasound, a device that combines surface acoustic waveform (SAW) low-frequency ultrasound with hyper- oxygenated saline to deliver oxygen to wounds. Participants included 7 patients (7 men, median age 63 years, all with hypertension) with CLI and full-thickness wounds. Baseline therapy PaO2 measurements were taken before therapy, after provision of hyper-oxygenated saline, and after sonification. The device was found to successfully oxygenate the wound beds; PaO2 levels increased by a median of 59.7%, a maximum of 116%, and a median absolute difference peaking at 10.8 mmHg PaO2 (P = 0.018). In conclusion, the treatment increases wound oxy- gen levels and may be an option in CLI therapy.
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August 2012

Optimal techniques with the Diamondback 360° System achieve effective results for the treatment of peripheral arterial disease.

J Cardiovasc Transl Res 2011 Apr 11;4(2):220-9. Epub 2011 Feb 11.

Duke Raleigh Hospital, Duke University Medical Center, 3320 Wake Forest Road, Raleigh, NC 27609, USA.

The Diamondback 360® Orbital PAD System (DB360) is a novel orbital atherectomy system for the treatment of calcified lower extremity lesions associated with peripheral arterial disease (PAD). This percutaneous, endovascular system incorporates the use of centrifugal force and differential sanding to modify plaque morphologies. The mechanism of differential sanding discriminates between compliant arterial tissue and diseased fibro-calcific or calcific plaque. An eccentrically mounted diamond-coated crown orbits at high speeds and removes a thin layer of calcific plaque with each pass of the crown. The crown creates a more concentric, smooth vessel lumen with increased diameter, increased lesion compliance and improved blood flow while protecting the vessel media. As a result, the risk for post-procedure thrombus formation and potential for restenosis may be reduced. The risk of intra-procedural events (slow flow, hemolysis, spasm and pain) may be reduced due to the design of this orbital sanding system along with proper technique. Extensive benchtop, in vivo, and clinical testing has confirmed these results and is presented within this paper. In addition, guidelines for selecting the most appropriate crown size and type (solid versus classic) and step-by-step procedural technique and pharmacology information are presented. The DB360 System provides a safe, efficacious, and cost-effective endovascular method for PAD treatment. Careful understanding of procedural methods, use of pharmacological drugs, and understanding of device operation contributes to improved treatment success.
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http://dx.doi.org/10.1007/s12265-010-9255-xDOI Listing
April 2011

Ototoxicity after combined platinum and fractionated radiation in a novel guinea pig model.

Am J Otolaryngol 2009 Jan-Feb;30(1):1-7. Epub 2008 Jun 20.

Otolaryngology Department, University of Minnesota, Minneapolis, MN, USA.

Purpose: Cis-platinum and radiation in combination are current organ preservation treatment strategies for head and neck cancer. Their individual ototoxicity has been investigated, with recent demonstration of ototoxicity in clinical studies. Currently, no ototoxicity studies have been performed in animals receiving similar schedules of radiation or cis-platinum to those patients with head and neck cancer.

Materials And Methods: In the present study, an animal model was developed to investigate the effects of combined modality therapy on hearing. Albino guinea pigs were given equivalent protocol dosages of cis-platinum (3 parenteral courses), fractionated radiation (25 fractions over 5 weeks), or both. Click and tone burst auditory brainstem response (ABR) measurements were performed before and 6 weeks after the completion of treatment.

Results: Animals receiving radiation or cis-platinum and radiation experienced permanent significant ABR shifts at all frequencies, with 33% of the animals experiencing complete unilateral sensorineural hearing loss at 2 or more frequencies in the ear receiving the full radiation dose (7075 cGy over 25 fractions) (P < .05, paired t test analysis). The animals receiving 3 doses of cis-platinum had no significant ABR threshold shifts at 6 weeks. These data suggest that cis-platinum and radiation cause greater ototoxicity than cis-platinum alone. These findings correlate closely with sensorineural hearing loss in combined modality patients at our institution and in recent studies.

Conclusions: We conclude that the current animal results parallel those seen clinically and serve as a model for ototoxicity from combined modality therapies in future protocols.
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http://dx.doi.org/10.1016/j.amjoto.2007.12.003DOI Listing
January 2009

Risks and benefits of antiplatelet therapy in uremic patients.

Adv Chronic Kidney Dis 2008 Oct;15(4):370-7

Duke Heart Center, Department of Medicine, and Duke Clinical Research Institute, Duke University Medical Center, Durham, NC 27710, USA.

Patients with renal insufficiency are at an increased risk for cardiovascular morbidity and mortality. Despite being at a substantial risk for thrombotic events, patients with renal insufficiency also experience a greater number of hemorrhagic complications associated with antiplatelet therapy than individuals with normal renal function. This review focuses on the benefits and risks of antiplatelet therapy in patients with impaired kidney function suffering from an acute coronary syndrome.
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http://dx.doi.org/10.1053/j.ackd.2008.07.006DOI Listing
October 2008

Acute in-vivo evaluation of bleeding with Gelfoam plus saline and Gelfoam plus human thrombin using a liver square lesion model in swine.

J Thromb Thrombolysis 2009 Jul 16;28(1):1-5. Epub 2008 Jul 16.

Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.

Background: Management of post-operative bleeding has historically used topical bovine thrombin. However, possible harm through activation of coagulation inhibitors has encouraged investigation with other hemostatic agents. This study utilized a novel ordinal bleeding model to test whether a Gelfoam + human thrombin solution is superior at controlling bleeding when compared to Gelfoam + saline solution at different time intervals.

Study Design: Four swine underwent open laparotomy after receiving unfractionated heparin. Twenty open liver biopsies were performed in each swine; ten biopsies treated with Gelfoam + human thrombin solution and 10 biopsies treated with Gelfoam + saline solution. Three, 6 min, and 12 min after the procedure, bleeding was objectively graded by a four-point model.

Results: There was a significant (P < 0.017), treatment effect on each success/failure outcome (success = bleeding score 1) at 3 (P < 0.001), 6 (P < 0.001), and 12 (P = 0.003) min, based on a 2 x 2 Fisher's exact test. Similarly, there was a significant treatment effect on each success/failure outcome and four-point bleeding score based on a multiple logistic regression analysis controlling for pig, lesion weight, and initial bleeding taking into consideration repeated measures at three time points.

Conclusions: The results demonstrate a superior treatment effect for control of bleeding using human thrombin compared to a saline solution. Future studies should compare bovine thrombin versus human thrombins ability to control bleeding as well as the hazard of each in activating coagulation inhibitors.
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http://dx.doi.org/10.1007/s11239-008-0249-3DOI Listing
July 2009

Evaluation of combined cardiac positron emission tomography and coronary computed tomography angiography for the detection of coronary artery disease.

Nucl Med Commun 2008 Jul;29(7):593-8

Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.

Background: Coronary artery disease is a leading cause of morbidity and mortality. Multiple imaging modalities are used to screen for significant coronary artery disease. We report the concordance between coronary computed tomography angiography (CTA) and stress cardiac positron emission tomography (CPET) to detect significant coronary artery disease, the feasibility of combining CTA and CPET in one diagnostic test, and the ability of CTA and CPET to detect significant coronary artery disease by comparison with cardiac catheterization.

Methods: Forty patients were prospectively enrolled and imaged with a hybrid PET/CT scanner. Eighteen patients had cardiac catheterization data for comparison. Concordance of findings between diagnostic tests was assessed by examining overall percentage in agreement, area under the receiver operating characteristic curve, sensitivity, specificity, and positive and negative predictive values.

Results: The overall agreement between CTA and CPET for detecting significant coronary artery disease was 76.3% with a sensitivity and specificity of 91.7 and 69.2%, respectively. The overall agreement between CTA and cardiac catheterization for detecting significant coronary artery disease was 81.3% with a sensitivity and specificity of 81.8 and 80.0%, respectively. The overall agreement between CPET and cardiac catheterization for detecting significant coronary artery disease was 77.8% with a sensitivity and specificity of 76.9 and 80.0%, respectively.

Conclusion: CTA and CPET can be performed in a single diagnostic test interval to simultaneously assess the extent of coronary artery disease and its hemodynamic significance. The sensitivity and specificity of CTA and CPET are similar to existing noninvasive screening tests.
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http://dx.doi.org/10.1097/MNM.0b013e3282f8143bDOI Listing
July 2008

Repeatability and reproducibility of phase analysis of gated single-photon emission computed tomography myocardial perfusion imaging used to quantify cardiac dyssynchrony.

Nucl Med Commun 2008 Apr;29(4):374-81

Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.

Background: A novel method to quantify dyssynchrony has been developed using phase analysis of gated single-photon emission computed tomography perfusion imaging. We report on the effect of variability in image reconstruction on the phase analysis results (repeatability) and on the interobserver and intraobserver reproducibility of the technique.

Methods: Phase standard deviation (SD) and bandwidth are phase indices that quantify dyssynchrony. To evaluate repeatability, raw data sets were processed twice in 50 patients with left ventricular dysfunction and 50 normal controls. To determine the optimal processing method, two replicated phase analysis results were obtained using automated and manual base parameter placement. Reproducibility of the phase analysis was determined using the data from 20 patients.

Results: In normal controls, manual base parameter placement improves repeatability of the phase analysis as measured by the mean absolute difference between two reads for phase SD (12.0 degrees vs. 1.2 degrees , P<0.0001) and bandwidth (33.7 degrees vs. 3.6 degrees , P<0.0001). Repeatability is better for normal controls than for patients with left ventricular dysfunction for phase SD (1.2 degrees vs. 6.0 degrees , P<0.0001) and bandwidth (3.6 degrees vs. 26.5 degrees , P<0.0001). Reproducibility of the phase analysis is high as measured by the intraclass correlation coefficients for phase SD and bandwidth of 0.99 and 0.99 for the interobserver comparisons and 1.00 and 1.00 for the intraobserver comparisons.

Conclusion: A novel method to quantify dyssynchrony has been developed using gated single-photon emission computed tomography perfusion imaging. Manual base parameter placement reduces the effect that variability in image reconstruction has on phase analysis. A high degree of reproducibility of phase analysis is observed.
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http://dx.doi.org/10.1097/MNM.0b013e3282f81380DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3048057PMC
April 2008

Effectiveness of Glycerol Mono-oleate as a Biosealant.

J Invasive Cardiol 2008 Jan;20(1):29-34

Department of Medicine, Duke University Medical Center, Box 2622, Durham, NC, 27710, USA.

Background: The number of femoral artery catheterizations will increase over the next decade to more than 9 million worldwide. Accordingly, a new era of access site management with vascular closure techniques utilizing biologics are being developed and implemented. Glycerol mono-oleate (GMO) is one such biologic - a biodegradable compound that changes from a solid phase to a bioadhesive swollen semisolid phase when exposed to aqueous solutions and heat. We assessed whether GMO would: 1) achieve hemostasis more effectively than control when injected into a swine liver biopsy tract; and 2) inhibit common percutaneous procedure pathogens.

Methods: During the hemostasis experiment, seven swine anticoagulated with heparin (ACT > 250) underwent 10 open-liver biopsies with a 14 gauge cutting needle; 5 injected with GMO (treatment) and 5 injected with nothing (control). Thirty seconds, 2 minutes, 5 minutes and 10 minutes after the procedure, bleeding was objectively graded; 0 = no bleeding (success) and 1 = bleeding (failure). During the bacteria experiment, GMO was injected into plates containing culture media for 4 common percutaneous pathogens (Enteroccocis faecalis, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae). When injected, GMO converted to a semisolid phase with definitive margins in the culture media. Each bacterium was then coated over their respective media and GMO.

Results: The results showed a significant treatment effect (p < 0.017) on each success/failure bleeding outcome at 30 seconds (p < 0.0001), 2 minutes (p < 0.0001) and 5 minutes (p = 0.0038) based on a multiple logistic regression analysis controlling for initial bleeding, pig and side-of-liver biopsy (medial or lateral lobe). At 10 minutes, the bleeding results were not significant (p = 0.0917), likely explained by a pig's innate ability to clot at this time period. For the bacteria experiment, there was no growth of bacteria on the GMO for any of the plates. Specifically, the Staphylococcus aureus plate displayed a 200 micron halo containing no bacterial growth surrounding the GMO.

Conclusion: In conclusion, these results illustrate a significant hemostatic effect post liver biopsy at multiple time points using GMO. Furthermore, GMO displays bacterial deterrent properties.
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January 2008

Clinical results of a novel wide beam reconstruction method for shortening scan time of Tc-99m cardiac SPECT perfusion studies.

J Nucl Cardiol 2007 Jul;14(4):555-65

Department of Radiology, Division of Nuclear Medicine, Duke University Medical Center, Durham, NC 27710, USA.

Background: Newly developed reconstruction algorithms enable the acquisition of images at half of the scan time while maintaining image quality. The purpose of this investigation was to evaluate a novel wide beam reconstruction (WBR) method developed by UltraSPECT for decreasing scan times and to compare it with filtered backprojection (FBP), which is the technique routinely used.

Methods And Results: Phantom and clinical studies were performed. Hot and cold sphere and cardiac phantom acquisitions were reconstructed via WBR, FBP, and ordered-subsets expectation maximization. Fifty patients were prospectively studied by use of both a standard and a short protocol. The short protocol was performed first on 29 of 50 patients via 8-frame gated technetium 99m stress single photon emission computed tomography and low-energy high-resolution collimators. Stress Tc-99m studies (30-45 mCi) were scanned for 20 seconds per frame. For the short protocol, all parameters remained constant except for the time per frame, which was reduced by 50% on Tc-99m studies. All resting Tc-99m scans (36/50 patients) were processed with FBP for the standard full-scan time studies and with WBR for the short scan studies. The images were interpreted by use of a 17-segment model and 5-degree severity score, and the perfusion and functional variables were determined. Distributions including mean, median, and interquartile ranges were examined for all variables. The differences (FBP - WBR) were computed for all variables and were examined by use of nonparametric signed rank tests to determine whether the median difference was 0. The absolute value of the difference was also examined. Spearman rank-order correlation, a nonparametric measure of association, was used for the 2 methods to determine significant correlations between variables. The hot and cold sphere phantom studies demonstrated that WBR had improved contrast recovery and slightly better background uniformity than did the ordered-subsets expectation maximization. The cardiac phantom studies performed with attenuating medium and background activity showed that the half-scan time images processed with WBR had better contrast recovery and background uniformity than did the full-scan time FBP reconstruction. In the clinical studies, highly significant correlations were observed between WBR and FBP for functional as well as perfusion variables (P < .0001). The summed stress score, summed rest scores, and summed difference score were not statistically different for FBP and WBR (P > .05). Left ventricular volumes had a high correlation coefficient but were significantly larger with FBP than with WBR.

Conclusion: Our study results suggest that cardiac single photon emission computed tomography perfusion studies may be performed with the WBR algorithm using half of the scan time without compromising qualitative or quantitative imaging results.
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http://dx.doi.org/10.1016/j.nuclcard.2007.04.022DOI Listing
July 2007

Effect of exercise training on ventricular function, dyssynchrony, resting myocardial perfusion, and clinical outcomes in patients with heart failure: a nuclear ancillary study of Heart Failure and A Controlled Trial Investigating Outcomes of Exercise TraiNing (HF-ACTION); design and rationale.

Am Heart J 2007 Jul;154(1):46-53

Moses Cone Hospital, Greensboro, NC, USA.

Background: Technetium Tc 99m gated single photon emission computed tomography (SPECT) has become the cornerstone of noninvasive risk stratification in patients with ischemic heart disease, but its role in patients with heart failure is not as well established.

Study Design: This study is a substudy of the Heart Failure and A Controlled Trial Investigating Outcomes of Exercise TraiNing (HF-ACTION) trial--a National Institutes of Health/National Heart, Lung, and Blood Institute-funded randomized controlled trial--designed to evaluate the role of exercise training in patients with heart failure due to left ventricular dysfunction. For this substudy, a total of 300 patients distributed on an approximately 1:1 basis between the exercise training and usual care arms of HF-ACTION will undergo resting technetium Tc 99m gated SPECT at baseline and 12 months to compare changes in left ventricular function with exercise training. These changes, along with baseline data, will be correlated with changes in exercise parameters, inflammatory markers, and clinical outcomes: death, cardiovascular hospitalization, and quality of life scores. In a subset of patients, first-pass radionuclide ventriculography will be obtained to assess the relationship between ventricular dyssynchrony, ejection fraction, changes in exercise parameters, and outcomes.

Conclusion: The role of nuclear imaging in patients with heart failure remains poorly defined. This substudy aims to harness the power of a large heart failure trial (HF-ACTION) to further delineate the utility of technetium Tc 99m gated SPECT imaging and first-pass radionuclide ventriculography for predicting important clinical outcomes in this population.
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http://dx.doi.org/10.1016/j.ahj.2007.03.045DOI Listing
July 2007
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