Publications by authors named "Chaitu Cheruvu"

8 Publications

  • Page 1 of 1

Beyond Stenosis With Fractional Flow Reserve Via Computed Tomography and Advanced Plaque Analyses for the Diagnosis of Lesion-Specific Ischemia.

Can J Cardiol 2016 11 29;32(11):1315.e1-1315.e9. Epub 2016 Jan 29.

Department of Medicine and Radiology, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address:

In the treatment of stable coronary artery disease (CAD), the determination of stenosis severity by invasive coronary angiography (ICA) is a critical procedure, and for borderline lesions, the detection of ischemia through invasive fractional flow reserve (FFR) is the gold standard. With advances in computational fluid dynamics, FFR can now be calculated noninvasively using anatomic data from coronary computed tomographic angiography (CCTA). This technique is known as FFR. The purpose of this review is to summarize the science of FFR, describe its diagnostic accuracy, discuss its clinical and economic impact, and elucidate factors beyond stenosis severity that may mechanistically relate to lesion-specific ischemia. These factors include adverse atherosclerotic plaque characteristics such as positive remodelling, low-attenuation plaque, and spotty calcification, as well as aggregate plaque volume. These factors can be appreciated noninvasively by CCTA but not by ICA. The diagnostic accuracy of FFR, compared with the gold standard of FFR, has been validated in 3 prospective multicentre blinded core laboratory-controlled trials, and as a result FFR has been approved by the US Food and Drug Administration for clinical use. FFR has also been shown in a clinical utility trial to better identify patients without obstructive CAD when compared with standard noninvasive assessment of stable CAD, thereby avoiding unnecessary angiograms. In addition, the use of FFR has been shown to allow for a significant cost savings compared with traditional care. It is therefore important for cardiologists to appreciate the value of this important new methodology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cjca.2016.01.023DOI Listing
November 2016

Long-Term Prognostic Utility of Coronary CT Angiography in Stable Patients With Diabetes Mellitus.

JACC Cardiovasc Imaging 2016 11 24;9(11):1280-1288. Epub 2016 Aug 24.

Department of Radiology and Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address:

Objectives: The goal of this study was to determine the long-term prognostic value of coronary computed tomography angiography (CTA) among patients with diabetes mellitus (DM) compared with nondiabetic subjects.

Background: The long-term prognostic value of coronary CTA in patients with DM is not well established.

Methods: Patients enrolled in the CONFIRM (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter) registry with 5-year follow-up data were identified. The extent and severity of coronary artery disease (CAD) were analyzed at baseline coronary CTA and in relation to outcomes between diabetic and nondiabetic patients. CAD according to coronary CTA was defined as none (0% stenosis), nonobstructive (1% to 49% stenosis), or obstructive (≥50% stenosis). Time to death (and in a subgroup, time to major adverse cardiovascular event) was estimated by using multivariable Cox proportional hazards models.

Results: A total of 1,823 patients were identified as having DM with 5-year clinical follow-up and were propensity-matched to 1,823 patients without DM (mean age 61.8 ± 10.9 years; 54.4% male). Patients with DM did not exhibit a heightened risk of death compared with the propensity-matched nondiabetic subjects in the absence of CAD on coronary CTA (risk-adjusted hazard ratio [HR] of DM: 1.32; 95% confidence interval [CI]: 0.78 to 2.24; p = 0.296). Patients with DM were at increased risk of dying compared with nondiabetic subjects in the setting of nonobstructive CAD (in the propensity-matched cohort: HR, 2.10; 95% CI: 1.43 to 3.09; p < 0.001) with a mortality risk greater than nondiabetic subjects with obstructive disease (p < 0.001). In a risk-adjusted hazard analysis among patients with DM, both per-patient obstructive CAD and nonobstructive CAD conferred an increase in all-cause mortality risk compared with patients without atherosclerosis on coronary CTA (nonobstructive disease-HR: 2.07; 95% CI: 1.33 to 3.24; p = 0.001; obstructive disease-HR: 2.22; 95% CI: 1.47 to 3.36; p < 0.001).

Conclusions: Among patients with DM, nonobstructive and obstructive CAD according to coronary CTA were associated with higher rates of all-cause mortality and major adverse cardiovascular events at 5 years, and this risk was significantly higher than in nondiabetic subjects. Importantly, patients with DM without CAD according to coronary CTA were at a risk comparable to that of nondiabetic subjects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcmg.2015.12.027DOI Listing
November 2016

A systematic review and meta-analysis of multidetector computed tomography in the assessment of coronary artery bypass grafts.

Int J Cardiol 2016 Oct 1;221:898-905. Epub 2016 Jul 1.

The Collaborative Research Group, Macquarie University, Sydney, Australia. Electronic address:

Purpose: The present meta-analysis aimed to compare the diagnostic accuracy of more recent computed tomography coronary angiography (CTCA) with invasive coronary angiography (ICA) in the assessment of graft patency after coronary artery bypass graft surgery (CABG).

Material And Methods: A systematic review was performed using nine electronic databases from their dates of inception to July 2015. Predefined inclusion criteria included studies reporting on comparative outcomes using ≥64 slice multidetector computed tomography (MDCT) and ICA. The primary endpoints included graft occlusion and significant graft stenosis ≥50%. Secondary analyses included the comparison of arterial versus venous graft conduits, and the use of different MDCT techniques.

Results: Thirty-one studies were identified according to selection criteria, involving 1975 patients with 5364 assessed grafts. Combined assessment of stenosis and occlusion for all grafts demonstrated a sensitivity of 96.1% [95% confidence interval (CI) 94.3-97.4%] and specificity of 96.3% (95% CI 95.1-97.3%). CTCA assessment of venous grafts demonstrated higher sensitivity compared to arterial grafts, when testing for both occlusion and stenosis (97.6% vs 89.2%, p=0.004).

Conclusion: Results of this study demonstrated that CTCA had a relatively high pooled sensitivity, specificity and negative predictive value compared to ICA. However, patient baseline characteristics varied between studies, and the results should be interpreted with caution. Nonetheless, our results indicate that CTCA should be recognized as an accurate and non-invasive investigation for graft patency in symptomatic patients after CABG.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijcard.2016.06.264DOI Listing
October 2016

Long term prognostic utility of coronary CT angiography in patients with no modifiable coronary artery disease risk factors: Results from the 5 year follow-up of the CONFIRM International Multicenter Registry.

J Cardiovasc Comput Tomogr 2016 Jan-Feb;10(1):22-7. Epub 2015 Dec 15.

Department of Medicine and Radiology, University of British Columbia, Vancouver, BC, Canada. Electronic address:

Background: Coronary computed tomography angiography (coronary CTA) can prognosticate outcomes in patients without modifiable risk factors over medium term follow-up. This ability was driven by major adverse cardiovascular events (MACE).

Objective: Determine if coronary CTA could discriminate risk of mortality with longer term follow-up. In addition we sought to determine the long-term relationship to MACE.

Methods: From 12 centers, 1884 patients undergoing coronary CTA without prior coronary artery disease (CAD) or any modifiable CAD risk factors were identified. The presence of CAD was classified as none (0% stenosis), mild (1% to 49% stenosis) and obstructive (≥50% stenosis severity). The primary endpoint was all-cause mortality and the secondary endpoint was MACE. MACE was defined as the combination of death, nonfatal myocardial infarction, unstable angina, and late target vessel revascularization (>90 days).

Results: Mean age was 55.6 ± 14.5 years. At mean 5.6 ± 1.3 years follow-up, 145(7.7%) deaths occurred. All-cause mortality demonstrated a dose-response relationship to the severity and number of coronary vessels exhibiting CAD. Increased mortality was observed for >1 segment non-obstructive CAD (hazard ratio [HR]:1.73; 95% confidence interval [CI]: 1.07-2.79; p = 0.025), obstructive 1&2 vessel CAD (HR: 1.70; 95% CI: 1.08-2.71; p = 0.023) and 3-vessel or left main CAD (HR: 2.87; 95% CI: 1.57-5.23; p = 0.001). Both obstructive CAD (HR: 6.63; 95% CI: 3.91-11.26; p < 0.001) and non-obstructive CAD (HR: 2.20; 95% CI: 1.31-3.67; p = 0.003) predicted MACE with increased hazard associated with increasing CAD severity; 5.60% in no CAD, 13.24% in non-obstructive and 36.28% in obstructive CAD, p < 0.001 for trend.

Conclusions: In individuals being assessed for CAD with no modifiable risk factors, all-cause mortality in the long term (>5 years) was predicted by the presence of more than 1 segment of non-obstructive plaque, obstructive 1- or 2-vessel CAD and 3 vessel/left main CAD. Any CAD, whether non-obstructive or obstructive, predicted MACE over the same time period.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcct.2015.12.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4869323PMC
October 2016

An Unusual Case of Cannula Obstruction Resulting from Venous Thromboembolism.

J Extra Corpor Technol 2014 Sep;46(3):267-9

Cerebral strokes of unknown origin frequently present with a patent foramen ovale (PFO), a common atrial septal defect occurring in approximately 25% of the adult population. Deep vein thrombosis (DVT) or pulmonary embolism (PE) in the presence of a PFO can produce paradoxical systemic embolization subsequent to an increase in pulmonary pressure, permitting entry of thrombi into the arterial circulation. Diagnosis of an impending paradoxical embolism (IPDE) involves the detection of DVT or PE in the presence of an abnormal communication between left and right circulations and may include a right-to-left shunt. Treatment includes oral anticoagulation, antiplatelet agents, thrombolysis, transcatheter closure of the defect, or surgical embolectomy and PFO closure. As a result of risks of intracranial hemorrhage with fibrinolysis, pulmonary embolectomy using cardiopulmonary bypass (CPB) and deep hypothermia is a primary treatment with a surgical mortality rate at approximately 5%. Despite optimal management, IPDE is associated with a mortality rate of 18%. Prompt diagnosis and treatment is critical in avoiding systemic thromboembolization and strokes in these patients. We report a case of superior vena cava cannula obstruction resulting from a paradoxical embolus traversing a PFO during surgery. Warning signs and management during CPB are discussed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4566838PMC
September 2014

Imaging the Aortic Annulus with Multi-Detector Computed Tomography and 3-Dimensional Transesophageal Echocardiography.

Interv Cardiol Clin 2015 Jan 9;4(1):23-37. Epub 2015 Feb 9.

Department of Medical Imaging, St. Paul's Hospital, University of British Columbia, 1081 Burrard Street, Vancouver, British Columbia V6S 1Y6, Canada. Electronic address:

Degenerative aortic stenosis is the most common cause of valvular heart disease in Western nations. Transcatheter aortic valve replacement (TAVR) is an alternative therapy for inoperable or high-risk patients with symptomatic severe aortic stenosis. Three-dimensional imaging techniques provide multiplanar imaging, allowing precise measurements of the noncircular aortic annulus and complex anatomy of the aortic root. These measurements influence patient eligibility, allow adequate prosthesis sizing, and determine the success of implantation and likelihood of complications. This review compares imaging modalities and addresses their strengths and weaknesses to assess the aortic annulus and other aortic root structures.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.iccl.2014.09.002DOI Listing
January 2015

Isolated hypertrophy of the basal ventricular septum: characteristics of patients with and without outflow tract obstruction.

Int J Cardiol 2014 May 20;173(3):487-93. Epub 2014 Mar 20.

Department of Cardiology & The University of Sydney, Sydney Medical School, Level 3 West, Concord Repatriation General Hospital, Hospital Road, Concord, Sydney, NSW 2139, Australia. Electronic address:

Background: Isolated basal septal hypertrophy (IBSH) of the left ventricle (LV) is not a well understood phenomenon, particularly in the presence of concomitant left ventricular outflow tract obstruction (LVOTO). We evaluated the prevalence of IBSH and compared those with and without LVOTO.

Methods: Retrospective observational study of 4104 consecutive patients undergoing echocardiography at a community cardiology practice and a hospital without specialized Hypertrophic Cardiomyopathy (HCM) service to determine prevalence of IBSH, defined as isolated hypertrophy (>15 mm) of the basal LV septum (BS) without hypertrophy elsewhere. Clinical, ECG and echocardiographic characteristics were compared in IBSH with and without LVOTO.

Results: Prevalence of IBSH was 5.8% (240/4104): mean (SD) age was 76.0y (10.4) with equal gender distribution. Prevalence increased with age (p<0.001 for trend), reaching 7.8% over 70y. None had a family history of HCM, and HCM-associated ECG changes were uncommon. Mean BS thickness (SD) was 17.8mm (0.24) with a BS/posterior wall ratio (SD) of 1.76 (0.31). Resting peak LVOT gradient (>20mmHg) was present in 8/240 (3.3%), mean (SD) 69.6mmHg (59.3). Patients with LVOTO had hypercontractile LV function (fractional shortening [SD] 51.8% [9.5] vs. 40.5% [10.9], p=0.012) compared to those without LVOTO, but had similar BS thickness [SD] (17.8mm [3.0] vs. 17.8mm [2.8], p=0.996) and ECG characteristics. Greater apical and septal displacements of the mitral valve co-aptation point characterized those with IBSH and LVOTO.

Conclusions: IBSH is common in elderly patients referred for echocardiography. LVOTO occurs only when concomitant mitral valve co-aptation and LV hypercontractility facilitate development of a gradient, rather than through differences in the degree of BS myocardial hypertrophy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijcard.2014.03.078DOI Listing
May 2014

Successful ablation of incessant AV reentrant tachycardia in a patient on extracorporeal membrane oxygenation.

Heart Lung Circ 2014 Jan 6;23(1):e12-5. Epub 2013 Aug 6.

Department of Cardiology, St Vincent's Hospital, Sydney, New South Wales, Australia; Faculty of Medicine, University of New South Wales, Australia; Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia.

We present the first described case of an accessory pathway ablation, requiring a transseptal puncture, performed on ECMO for tachycardia-induced cardiomyopathy in the context of cardiogenic shock. The performance of a transseptal puncture in such a scenario is a feasible option and should be considered if the clinical situation dictates, despite the inherent risks. After ablation of the left lateral pathway the patient was successfully weaned off ECMO and made a complete recovery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.hlc.2013.06.011DOI Listing
January 2014