Publications by authors named "Tae-Hyun Yang"

90 Publications

Effect of Significant Coronary Artery Stenosis on Prognosis in Patients with Vasospastic Angina: A Propensity Score-Matched Analysis.

J Clin Med 2021 Jul 28;10(15). Epub 2021 Jul 28.

Division of Cardiology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul 06649, Korea.

Vasospastic angina (VA) is a functional disease of the coronary artery and occurs in an angiographically normal coronary artery. However, it may also occur with coronary artery stenosis. We investigated the effect of coronary artery stenosis on clinical outcomes in VA patients. Study data were obtained from a prospective multicenter registry that included patients who had symptoms of VA. Patients were classified into two groups according to presence of significant coronary artery stenosis. Among 1920 patients with VA, 189 patients were classified in the "significant stenosis" group. The one-year composite clinical events rate was significantly higher in the significant stenosis group than in the "no significant stenosis" group (5.8% vs. 1.4%, respectively; < 0.001). Additionally, the prevalence of ACS was significantly greater in the "significant stenosis" group (4.8% vs. 0.9%, respectively; < 0.001). After propensity score matching, the adverse effects of significant stenosis remained. In addition, significant stenosis was independently associated with a 6.67-fold increased risk of ACS in VA patients. In conclusion, significant coronary artery stenosis can increase the adverse clinical outcomes in VA patients at long-term follow-up. Clinicians should manage traditional risk factors associated with atherosclerosis and control vasospasm as well as reduce the burden of atherosclerosis.
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July 2021

Enhancement of Catalytic Activity and Durability of Pt Nanoparticle through Strong Chemical Interaction with Electrically Conductive Support of Magnéli Phase Titanium Oxide.

Nanomaterials (Basel) 2021 Mar 24;11(4). Epub 2021 Mar 24.

Fuel Cell Laboratory, Korea Institute of Energy Research (KIER), 152, Gajeong-ro, Yuseong-gu, Daejeon 34129, Korea.

In this study, we address the catalytic performance of variously sized Pt nanoparticles (NPs) (from 1.7 to 2.9 nm) supported on magnéli phase titanium oxide (MPTO, TiO) along with commercial solid type carbon (VXC-72R) for oxygen reduction reaction (ORR). Key idea is to utilize a robust and electrically conductive MPTO as a support material so that we employed it to improve the catalytic activity and durability through the strong metal-support interaction (SMSI). Furthermore, we increase the specific surface area of MPTO up to 61.6 m g to enhance the SMSI effect between Pt NP and MPTO. After the deposition of a range of Pt NPs on the support materials, we investigate the ORR activity and durability using a rotating disk electrode (RDE) technique in acid media. As a result of accelerated stress test (AST) for 30k cycles, regardless of the Pt particle size, we confirmed that Pt/MPTO samples show a lower electrochemical surface area (ECSA) loss (<20%) than that of Pt/C (~40%). That is explained by the increased dissolution potential and binding energy of Pt on MPTO against to carbon, which is supported by the density functional theory (DFT) calculations. Based on these results, we found that conductive metal oxides could be an alternative as a support material for the long-term fuel cell operation.
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March 2021

Smoking may be more harmful to vasospastic angina patients who take antiplatelet agents due to the interaction: Results of Korean prospective multi-center cohort.

PLoS One 2021 2;16(4):e0248386. Epub 2021 Apr 2.

Division of Cardiology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea.

Background: The interaction between smoking and the use of antiplatelet agents on the prognosis of vasospastic angina (VA) is rarely investigated.

Methods: VA-Korea is a nation-wide multi-center registry with prospective design (n = 1812). The primary endpoint was the composite occurrence of acute coronary syndrome (ACS), symptomatic arrhythmia, and cardiac death. Log-rank test and Cox proportional hazard model were for statistical analysis. Also, we conducted interaction analysis in both additive and multiplicative scales between smoking and antiplatelet agents among VA patients. For additive scale interaction, relative excess risk due to interaction (RERI) was calculated and for multiplicative scale interaction, the ratio of hazard ratio (HR) was calculated. All statistical analysis conducted by Stata Ver 16.1.

Results: Patients who were smoking and using antiplatelet agents had the highest incidence rate in the primary composite outcome. The incidence rate was 3.49 per 1,000 person-month (95% CI: 2.30-5.30, log-rank test for primary outcome p = 0.017) and HR of smoking and using antiplatelet agents was 1.66 (95%CI: 0.98-2.81). The adjusted RERI of smoking and using antiplatelet agents was 1.10 (p = 0.009), and the adjusted ratio of HR of smoking and using antiplatelet agents was 3.32 (p = 0.019). The current study observed the interaction between smoking and using antiplatelet agents in both additive and multiplicative scales.

Conclusions: Smoking was associated with higher rates of unfavorable clinical outcomes among VA patients taking antiplatelet agents. This suggested that VA patients, especially those using antiplatelet agents should quit smoking.
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September 2021

Long-Term Left Atrial Function after Device Closure and Surgical Closure in Adult Patients with Atrial Septal Defect.

J Cardiovasc Imaging 2021 Apr 26;29(2):123-132. Epub 2020 Nov 26.

Division of Cardiology, Department of Internal Medicine, Inje University Busan Paik Hospital, Busan, Korea.

Background: Studies comparing left atrial (LA) function after surgical closure or percutaneous closure in patients with an atrial septal defect (ASD) are lacking.

Methods: Between 1 and 3 years after ASD treatment, we retrospectively analyzed the medical records and transthoracic echocardiographic images of patients who had been diagnosed with an ASD after 20 years of age and who had undergone surgical closure (ASD-S) or percutaneous device closure (ASD-D). We measured LA peak systolic, early diastolic, and late diastolic strain values using 2-dimensional (2D) speckle tracking echocardiography (STE) and calculated reservoir, conduit, and contraction strain.

Results: The reservoir strain value of the ASD-D groups was 25.2% ± 7.4%, which was lower compared to the control group (33.6% ± 5.5%) (p = 0.004). The LA conduit strain and the LA contraction values of the ASD-D group were also lower compared to the control group (-13.8% ± 5.8% vs. -20.4% ± 4.7%, p = 0.034; -11.3% ± 4.2% vs. -13.2% ± 2.5%, p = 0.037, respectively). The reservoir, conduit, and contraction strains of the ASD-S group were 27.8% ± 8.8%, -15.3% ± 6.4%, and -12.5% ± 5.8%, respectively, and were not different from those of the control group or the ASD-D group.

Conclusions: The 2D STE is a suitable method for evaluating LA function after ASD closure. Our results demonstrate that 1 year after device closure, the LA reservoir, conduit and contraction function were reduced in ASD-D group compared to healthy controls, while there was no difference between the ASD-S and ASD-D groups.
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April 2021

Quaternary Ammonium-Bearing Perfluorinated Polymers for Anion Exchange Membrane Applications.

Membranes (Basel) 2020 Oct 26;10(11). Epub 2020 Oct 26.

Fuel Cell Laboratory, Korea Institute of Energy Research, Daejoen 34129, Korea.

Perfluorinated polymers are widely used in polymer electrolyte membranes because of their excellent ion conductivity, which are attributed to the well-defined morphologies resulting from their extremely hydrophobic main-chains and flexible hydrophilic side-chains. Perfluorinated polymers containing quaternary ammonium groups were prepared from Nafion- and Aquivion-based sulfonyl fluoride precursors by the Menshutkin reaction to give anion exchange membranes. Perfluorinated polymers tend to exhibit poor solubility in organic solvents; however, clear polymer dispersions and transparent membranes were successfully prepared using -methyl-2-pyrrolidone at high temperatures and pressures. Both perfluorinated polymer-based membranes exhibited distinct hydrophilic-hydrophobic phase-separated morphologies, resulting in high ion conductivity despite their low ion exchange capacities and limited water uptake properties. Moreover, it was found that the capacitive deionization performances and stabilities of the perfluorinated polymer membranes were superior to those of the commercial Fumatech membrane.
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October 2020

Community-Based Pre-Hospital Electrocardiogram Transmission Program for Reducing Systemic Time Delay in Acute ST-Segment Elevation Myocardial Infarction.

Korean Circ J 2020 Aug;50(8):709-719

Department of Cardiology, Dong-A University Hospital, Dong-A University College of Medicine, Busan, Korea.

Background And Objectives: In acute ST-segment elevation myocardial infarction (STEMI), on-site transmission of electrocardiogram (ECG) has been shown to reduce systemic time delay to reperfusion and improve outcomes. However, it has not been adopted in community-based emergency transport system in Korea.

Methods: Busan Regional Cardio-cerebrovascular Center and Busan Metropolitan City Fire and Safety Headquarters (BMFSH) jointly developed and conducted a pre-hospital ECG transmission program. Seven tertiary hospitals and 22 safety stations of BMFSH participated. Systemic time delay to reperfusion of STEMI patients in the program was compared with that of 95 patients transported by 119 emergency medical system (EMS) before the program was implemented.

Results: During the study period, 289 ECG transmissions were made by 119 EMS personnel, executed within 5 minutes in 88.1% of cases. Of these, 42 ECGs were interpreted as ST-segment elevation. Final diagnosis of STEMI was made in 20 patients who underwent primary percutaneous coronary intervention. With the program, systemic time delay to reperfusion was significantly reduced (median [interquartile range; IQR], 76.0 [62.2-98.7] vs. 90.0 [75.0-112.0], p<0.01). Significant reduction of door-to-balloon time was also observed (median [IQR], 45.0 [34.0-69.5] vs. 58.0 [51.0-68.0], p=0.03). The proportion of patients with systemic time delay shorter than 90 minutes rose (51.6% vs. 75.0%, p=0.08) with pre-hospital ECG transmission.

Conclusions: We developed and implemented a community-based pre-hospital ECG transmission program for expeditious triage of STEMI patients. Significant reductions of systemic time delay and door-to-balloon time were observed. The expanded use of pre-hospital ECG transmission should be encouraged to realize the full potential of this program.
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August 2020

Effect of Operator Volume on In-Hospital Outcomes Following Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction: Based on the 2014 Cohort of Korean Percutaneous Coronary Intervention (K-PCI) Registry.

Korean Circ J 2020 Feb 18;50(2):133-144. Epub 2019 Nov 18.

Division of Cardiovascular, Department of Internal Medicine, Yeungnam University Medical Center, Yeungnam University College of Medicine, Daegu, Korea.

Background And Objectives: The relationship between operator volume and outcomes of percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI) has not been fully investigated. We aimed to investigate the relationship between operator PCI volume and in-hospital outcomes after primary PCI for STEMI.

Methods: Among the total of 44,967 consecutive cases of PCI enrolled in the Korean nationwide, retrospective registry (K-PCI registry), 8,282 patients treated with PCI for STEMI by 373 operators were analyzed. PCI volumes above the 75th percentile (>30 cases/year), between the 75th and 25th percentile (10-30 cases/year), and below the 25th percentile (<10 cases/year) were defined as high, moderate, and low-volume operators, respectively. In-hospital outcomes including mortality, non-fatal myocardial infarction (MI), stent thrombosis, stroke, and urgent repeat PCI were analyzed.

Results: The average number of primary PCI cases performed by 373 operators was 22.2 in a year. In-hospital mortality after PCI for STEMI was 571 cases (6.9%). In-hospital outcomes by operator volume showed no significant differences in the death rate, cardiac death, non-fatal MI, and stent thrombosis. However, the rate of urgent repeat PCI tended to be lower in the high-volume operator (0.6%) than in the moderate-(0.7%)/low-(1.5%) volume operator groups (p=0.095). The adjusted odds ratios for adverse in-hospital outcomes were similar in the 3 groups. Multivariate analysis also showed that operator volume was not a predictor for adverse in-hospital outcomes.

Conclusions: In-hospital outcomes after primary PCI for STEMI were not associated with operator volume in the K-PCI registry.
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February 2020

Clopidogrel plus Aspirin Use is Associated with Worse Long-Term Outcomes, but Aspirin Use Alone is Safe in Patients with Vasospastic Angina: Results from the VA-Korea Registry, A Prospective Multi-Center Cohort.

Sci Rep 2019 11 28;9(1):17783. Epub 2019 Nov 28.

Department of Cardiovascular Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea.

Anti-platelet agents are commonly used in vasospastic angina (VA) patients with comorbidity like coronary artery disease. However, long-term clinical outcomes in the use of aspirin, clopidogrel or the two agents together have rarely been investigated in VA patients. In a prospective study, we enrolled 2960 patients who received coronary angiography and ergonovine provocation test at 11 university hospitals in Korea. Among them, 1838 patients were diagnosed either with definite (n = 680) or intermediate (n = 1212) VA, using the criteria of chest pain, ECG changes and ergonovine provocation test results. They were analyzed according to their use of aspirin, clopidogrel or both, or no anti-platelet agent at all. The primary outcome was time to composite events of death from any cause, acute coronary syndrome (ACS) and symptomatic arrhythmia during a 3-year follow-up. A primary composite outcome was significantly more common in the aspirin plus clopidogrel group, at 10.8% (14/130), as compared with the non-antiplatelet group, at 4.4% (44/1011), (hazard ratio [HR] 2.41, 95% confidence interval [CI], 1.32-4.40, p = 0.004). With regard to the person-time event rate, similar results were shown, with the highest rate in the aspirin plus clopidogrel user at 4.72/1000 person months (95% CI, 2.79-7.96, log-rank test for primary outcome p = 0.016). The person-time event of the ACS rate was also highest in that group, at 2.81 (95% CI, 1.46-5.40, log-rank test for ACS p = 0.116). Kaplan-Meier survival analysis demonstrated poor prognosis in primary outcomes and ACS in aspirin plus clopidogrel users (log-rank test, p = 0.005 and p = 0.0392, respectively). Cox-proportional hazard regression analysis, adjusting for age, sex, history of coronary heart disease, hypertension, diabetes, presence or not of definite spasm, use of calcium channel blocker, demonstrated that the use of aspirin plus clopidogrel is an independent risk for the primary outcome (HR 2.01, CI: 1.07-3.81, p = 0.031). The aspirin-alone group had a similar primary and individual event rate compared to the no-antiplatelet agent group (HR 0.96, CI, 0.59-1.55, p = 0.872). Smokers using aspirin plus clopidogrel had poorer outcomes than non-smokers, with HR 6.36 (CI 2.31-17.54, p = 0.045 for interaction). In conclusion, among VA patients, aspirin plus clopidogrel use is associated with a poor clinical outcome at 3 years, especially in ACS. Aspirin alone appears to be safe for use in those patients.
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November 2019

Effectiveness and Safety of Zotarolimus-Eluting Stent (Resolute™ Integrity) in Patients with Diffuse Long Coronary Artery Disease.

Korean Circ J 2019 Aug 15;49(8):709-720. Epub 2019 May 15.

Division of Cardiology, Department of Internal Medicine, Inje University Haeundae Paik Hospital, Busan, Korea.

Background And Objectives: Diffuse long coronary artery disease (DLCAD) still has unfavorable clinical outcomes after successful percutaneous coronary intervention (PCI). Therefore, we aimed to evaluate the effectiveness and safety of Resolute™ zotarolimus-eluting stent (R-ZES; Resolute™ Integrity) for patients with DLCAD.

Methods: From December 2011 to December 2014, 1,011 patients who underwent PCI using R-ZES for CAD with longer than 25 mm lesion were prospectively enrolled from 21 hospitals in Korea. We assessed the clinical outcome of major adverse cardiac events (MACE) defined as the composite of cardiac death, non-fatal myocardial infarction (MI), and clinically-driven target vessel revascularization at 12 months.

Results: Mean age was 63.8±10.8 years, 701 (69.3%) patients were male, 572 (87.0%) patients had hypertension, 339 (33.8%) patients had diabetes, 549 (54.3%) patients diagnosed with acute MI and 545 (53.9%) patients had multi-vessel disease (MVD). A total of 1,697 stents were implanted into a total of 1,472 lesions. The mean diameter was 3.07±0.38 mm and the length was 28.27±6.97 mm. Multiple overlapping stents were performed in 205 (13.8%) lesions. A 12-month clinical follow-up was available in 1,004 patients (99.3%). The incidences of MACE and definite stent thrombosis at 12-month were 3.0% and 0.3% respectively. On multivariate Cox-regression analysis, multiple overlapping stents implantation, previous congestive heart failure, MVD, and age ≥75 years were independent predictors of one-year MACE.

Conclusions: Our study shows that R-ZES has an excellent 1-year clinical outcome in Korean patients with DLCAD.
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August 2019

Impact of multi-vessel vasospastic angina on cardiovascular outcome.

Atherosclerosis 2019 02 23;281:107-113. Epub 2018 Dec 23.

Department of Cardiovascular Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea. Electronic address:

Background And Aims: Since clinical characteristics and prognosis of patients with multi-vessel vasospastic angina (VSA) are not clear, we investigated the nature and prognosis of multi-vessel VSA in Koreans.

Methods: Among 2960 patients enrolled in the VA-KOREA (Vasospastic Angina in Korea) registry, 104 definite multi-vessel VSA patients, 163 single vessel VSA patients and 737 non-VSA patients were identified using the intracoronary ergonovine provocation test.

Results: Multi-vessel VSA and single vessel VSA groups showed similar baseline characteristics and medical treatment on discharge, but different from the non-VSA group. The primary composite endpoint (cardiac death, acute coronary syndrome, and symptomatic new onset arrhythmia) over a 36-month follow-up period was significantly higher in the multi-vessel VSA group than in the single vessel VSA and non-VSA groups (8.7% vs. 1.8% and 1.1%, each log-rank p < 0.05, respectively). The rate of death and acute coronary syndrome of the multi-vessel VSA group was higher than in the single vessel VSA and non-VSA groups (5.8% vs. 1.2% and 0.9%, each log-rank p < 0.05, respectively). In addition, multi-vessel VSA was an independent predictor of the primary composite endpoint at 36 months (HR 8.5, 95% CI [2.6-27.2], p < 0.0001).

Conclusions: Patients with multi-vessel VSA had worse clinical outcomes than single vessel VSA and non-VSA groups, suggesting that the existence of multi-vessel VSA itself is highly prognostic.
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February 2019

Evaluation of the flexural mechanical properties of various thermoplastic denture base polymers.

Dent Mater J 2018 Nov 7;37(6):950-956. Epub 2018 Mar 7.

Department of Removable Prosthodontics, School of Dental Medicine, Tsurumi University.

This study evaluated the flexural mechanical properties of various thermoplastic denture base polymers (six polyamides, four acrylic resins, polyester, polypropylene, and polycarbonate) by three different testing conditions; specimens were tested in water bath at 37°C (Wet/Water, by ISO 20795-1), or in ambient air (Wet/Air) after being immersed in distilled water for 50 h, or after desiccation for 7 days (Dry/Air). The mean ultimate flexural strength (UFS) and flexural modulus (FM) for most products ranged from 27 to 61 MPa and from 611 to 1,783 MPa respectively, which failed to meet the minimum requirements of the international standard, except for polycarbonate (89 and 2,245 MPa). The mean UFS and FM values were ranked Dry/Air>Wet/Air>Wet/Water (p<0.05). In conclusion, the flexural mechanical properties of denture base polymers varied with the products and were significantly affected by the testing medium (air or water) and specimen conditions (wet or dry).
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November 2018

The impact of a dose of the angiotensin receptor blocker valsartan on post-myocardial infarction ventricular remodelling.

ESC Heart Fail 2018 04 17;5(2):354-363. Epub 2018 Jan 17.

Division of Cardiology, Bong Seong Memorial Hospital, Busan, Republic of Korea.

Aims: Although clinical guidelines advocate the use of the highest tolerated dose of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers after acute myocardial infarction (MI), the optimal dosing or the risk-benefit profile of different doses have not been fully identified.

Methods And Results: In this multicentre trial, 495 Korean patients with acute ST segment elevation MI and subnormal left ventricular (LV) ejection fraction (<50%) were randomly allocated (2:1) to receive maximal tolerated dose of valsartan (titrated up to 320 mg/day, n = 333) or low-dose valsartan (80 mg/day, n = 162) treatment. The primary objective was to assess the changes in echocardiographic parameters of LV remodelling from baseline to 12 months after discharge. After treatment, end-diastolic LV volume (LVEDV) decreased significantly in the low-dose group, but the difference in LVEDV changes was insignificant between the maximal-tolerated-dose and low-dose groups. End-systolic LV volume decreased significantly in both groups, to a similar degree between groups. LV ejection fraction rose significantly in both study groups, to a similar degree. Changes in plasma levels of neurohormones were also comparable between the two groups. Drug-related adverse effects occurred more frequently in the maximal-tolerated-dose group than in the low-dose group (7.96 vs. 0.69%, P < 0.001).

Conclusions: In the present study, treatment with the maximal tolerated dose of valsartan did not exhibit a superior effect on post-MI LV remodelling compared with low-dose treatment and was associated with a greater frequency of adverse effect in Korean patients. Further study with a sufficient number of cases and statistical power is warranted to verify the findings of the present study.
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April 2018

Efficacy and Tolerability of Telmisartan/Amlodipine + Hydrochlorothiazide Versus Telmisartan/Amlodipine Combination Therapy for Essential Hypertension Uncontrolled With Telmisartan/Amlodipine: The Phase III, Multicenter, Randomized, Double-blind TAHYTI Study.

Clin Ther 2018 01 14;40(1):50-63.e3. Epub 2017 Dec 14.

Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Korea; Seoul National University Hospital, Seoul, Korea. Electronic address:

Purpose: This 8-week study in Korea aimed to evaluate the efficacy and tolerability of a telmisartan/amlodipine + hydrochlorothiazide (TAH) combination versus telmisartan/amlodipine (TA) combination in patients with essential hypertension that did not respond appropriately to 4-week treatment with TA.

Methods: All patients who met the inclusion criteria received TA (40/5 mg) during a 4-week run-in period (period 1). Patients who met the criteria for essential hypertension (mean sitting systolic blood pressure [MSSBP], ≥140 and <200 mm Hg, or ≥130 and<200 mm Hg in those with diabetes mellitus or chronic kidney disease) after period 1 were randomly assigned to receive TA 40/5 mg + hydrochlorothiazide 12.5 mg (test group) or TA only (control group). The test and control drugs were administered in each group for 2 weeks (period 2). Patients who completed period 2 underwent 6-week treatment (period 3) with a TAH and TA dose twice that in period 2. The primary end point was the change in MSSBP at week 8 of treatment. Secondary end points were the change in MSSBP at week 2 and MS diastolic BP, BP control rate, and BP response rate at weeks 2 and 8. Treatment tolerability was assessed based on adverse events (AEs), laboratory evaluations (chemistry, hematology, and urinalysis), 12-lead ECG, and physical examination including vital sign measurements.

Findings: We randomized 310 patients to the treatment groups. The mean (SD) ages of the TAH and TA groups were 62.0 (10.8) and 63.4 (10.4) years, respectively. The least squares mean change in MSSBP was significantly greater in the TAH group than in the TA group after 8 weeks (-18.7 vs -12.2 mm Hg; P < 0.001). Similar results were obtained on changes in MSSBP after 2 weeks and changes in sitting diastolic BP, BP control rate, and BP response rate at weeks 2 and 8 compared with the respective baseline values. The prevalences of treatment-emergent AEs (29.0% vs 16.3%; P = 0.008) and adverse drug reactions (20.0% vs 10.5%; P = 0.020) were significantly greater in the TAH group than in the TA group. Most treatment-emergent AEs were mild or moderate; none were severe. The most frequently reported AEs were dizziness and headache.

Implication: TAH triple therapy was more effective than was TA double therapy in reducing BP in these patients in Korea with essential hypertension that did not adequately respond to TA. identifier: NCT02738632.
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January 2018

Study protocol for a randomised controlled trial: harmonising optimal strategy for treatment of coronary artery stenosis - coronary intervention with next-generation drug-eluting stent platforms and abbreviated dual antiplatelet therapy (HOST-IDEA) trial.

BMJ Open 2017 10 11;7(10):e016617. Epub 2017 Oct 11.

Cardiovascular Centre, Department of Internal Medicine and Division of Cardiology, Seoul National University Hospital, Seoul, Korea.

Introduction: We have recently seen the introduction of newer generation drug-eluting stents with ultrathin struts that use advanced polymer technologies. However, the efficacy and safety of these newest stents have not yet been fully explored. In addition, there are still controversies over the optimal duration of dual antiplatelet therapy (DAPT) after stent implantation, particularly for ultrathin stents with the newest polymer technologies.

Methods And Analysis: The HOST-IDEA trial is a randomised, open-label, multicentre, non-inferiority trial and the first study to directly compare two of these ultrathin sirolimus-eluting stents: Orsiro stent with biodegradable polymer, and polymer-free Coroflex ISAR (CX-ISAR) stent. This study has a scheme of 2×2 factorial design according to the stent type and DAPT duration (3 vs 12 months). A total of 2152 patients will be randomised and stratified to demonstrate the non-inferiority of CX-ISAR to Orsiro, or of the abbreviated DAPT duration to the conventional 12 months (both in 1:1 ratio). For the comparison of stent type, the primary endpoint is target lesion failure (TLF), which is a composite of cardiac death, target vessel-related myocardial infarction and clinically driven target lesion revascularisation. For the comparison of DAPT duration, the net adverse clinical event is the coprimary endpoint, which is defined as a composite of TLF, definite/probable stent thrombosis and major bleeding.

Ethic Approval And Dissemination: All the institutions involved in this study are required to have ethical approval prior to patient enrolment. This multicentre study will recruit patients through competitive registration, but institutions that have not yet obtained ethical approvals have made it impossible to enrol patients in a centralised web database. The final results will be presented at relevant international conferences and will be materialised in the form of papers.

Trial Registration Number: NCT02601157; Pre-results.
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October 2017

Local Atrial/Ventricular Ratio as an Adjuvant Marker for Catheter Ablation of Atrioventricular Accessory Pathways.

Korean Circ J 2017 Jul 12;47(4):462-468. Epub 2017 Jul 12.

Department of Internal Medicine, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.

Background And Objectives: The earliest atrial (A)/ventricular (V) activation potential, or accessory pathway (AP) potential are commonly used as ablation targets for atrioventricular (AV) APs. However, these targets are sometimes ambiguous.

Subjects And Methods: We reviewed 119 catheter ablation cases in 112 patients diagnosed with orthodromic atrioventricular reentrant tachycardia (AVRT) or Wolff-Parkinson-White (WPW) syndrome. Local A/V amplitude potentials with the earliest activation or AP potential were measured shortly before achieving antegrade AP conduction block, ventriculoatrial block during right ventricle (RV) pacing, or AVRT termination with no AP conduction.

Results: APs were located in the left lateral (55.5%), left posterior (17.6%), left posteroseptal (10.1%), midseptal (1.7%), right posteroseptal (7.6%), right posterior (1.7%), and right lateral (5.9%) regions. The mean earliest activation time was 16.7±15.5 ms, mean A/V potential was 1.1±0.9/1.0±0.9 mV, and mean A/V ratio was 1.7±2.0. There was no statistically significant difference between the activation methods (antegrade vs. RV pacing vs. orthodromic AVRT) or AP locations (left vs. right atrium). However, when the local A/V ratio was divided into 3 groups (≤0.6, 1.0±0.3, and ≥1.4), the antegrade approach resulted in an A/V ratio greater than 1.0±0.3 (86.7%, p=0.007), and the orthodromic AVRT state resulted in a ratio of less than 1.0±0.3 (87.5%, p<0.001).

Conclusion: The mean local A/V potential and ratio did not differ by activation method or AP location. However, a different A/V ratio based on activation method (≥1.0±0.3, antegrade approach; and ≤1.0±0.3, orthodromic AVRT state) could be a good adjuvant marker for targeting AV APs.
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July 2017

Efficacy and Tolerability of Combination Therapy Versus Monotherapy with Candesartan and/or Amlodipine for Dose Finding in Essential Hypertension: A Phase II Multicenter, Randomized, Double-blind Clinical Trial.

Clin Ther 2017 Aug 19;39(8):1628-1638. Epub 2017 Jul 19.

Seoul Veterans Hospital, Seoul, Republic of Korea.

Purpose: Intensive blood pressure (BP) lowering is important for the treatment of hypertension; however, it has been a challenge to achieve target BP in many patients. The purpose of this study was to explore the optimal dosage of a fixed-dose combination of candesartan cilexetil (CAN) and amlodipine besylate (AML), by examining the tolerability and efficacy of CAN/AML combination therapy compared with those of monotherapy with either drug in patients with essential hypertension.

Methods: This Phase II multicenter, randomized, double-blind clinical trial enrolled patients aged 19 years or older with essential hypertension, defined as a mean sitting diastolic BP (msDBP) between 95 and 115 mm Hg, and a mean sitting systolic BP (msSBP) of <200 mm Hg after a 2-week placebo run-in period. A total of 635 patients were screened, of whom 439 were randomized to receive treatment; 425 patients were included in the full analysis set (combination therapy, 212; monotherapy, 213). Participants were randomly assigned to receive 1 of 8 treatments: CAN (8 or 16 mg), AML (5 or 10 mg), CAN/AML (8 mg/5 mg, 8 mg/10 mg, 16 mg/5 mg, or 16 mg/10 mg), once daily for 8 weeks.

Findings: After 8 weeks of treatment, changes in msDBP were significantly greater in the groups receiving CAN/AML combination therapies compared with monotherapies at matched doses, with the exception of CAN 8 mg/AML 10 mg versus AML 10 mg. The response to treatment and the achievement of target BP (both msSBP and msDBP) at week 8 were significantly greater overall in the groups that received combination therapy versus monotherapy. All medications were relatively well tolerated in each group.

Implications: Eight-week administration of CAN/AML (8 mg/5 mg, 16 mg/5 mg, and 16 mg/10 mg) resulted in a significantly greater BP reduction than that with CAN or AML monotherapy, and was determined to be well tolerated. identifier: NCT02944734.
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August 2017

Combined Use of Neutrophil to Lymphocyte Ratio and C-Reactive Protein Level to Predict Clinical Outcomes in Acute Myocardial Infarction Patients Undergoing Percutaneous Coronary Intervention.

Korean Circ J 2017 May 25;47(3):383-391. Epub 2017 May 25.

Department of Internal Medicine, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea.

Background And Objectives: Both neutrophil to lymphocyte ratio (NLR) and C-reactive protein (CRP) are biomarkers associated with poor prognosis of patients with acute myocardial infarction (AMI). However, the combined usefulness of NLR and CRP in predicting adverse outcomes has not been investigated.

Subjects And Methods: We analyzed 381 consecutive AMI patients who underwent percutaneous coronary intervention (PCI) from January 2012 to January 2014. The endpoints were all-cause mortality, recurrent myocardial infarction (MI), stent thrombosis, repeat revascularization, stroke, and major adverse cardiac and cerebrovascular events (MACCE) at 2-year follow-up. Included patients were divided into 4 groups according to the optimal cut-off values for NLR and CRP on receiver operating characteristic analysis predicting mortality.

Results: Patients with both high NLR (>6.30) and high CRP (>0.76) had significantly greater risk of all-cause death and MACCE at 24 months, with no significant increase in the risk of recurrent MI, stent thrombosis, or stroke compared with patients with either low NLR or low CRP, as well as those with low NLR and low CRP. Kaplan-Meier analysis revealed significantly lower survival in patients with high NLR-CRP. On Cox multivariate analysis, high NLR-CRP (hazard ratio 23.172, 95% confidence interval 6.575 to 81.671, p<0.001) was an independent predictor of all-cause death.

Conclusion: Elevated levels of both NLR and CRP are associated with increased risk of long-term mortality in AMI patients who have undergone PCI.
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May 2017

Comparison of the Antiplatelet Effects of Once and Twice Daily Low-Dose Ticagrelor and Clopidogrel After Percutaneous Coronary Intervention.

Am J Cardiol 2017 Jul 27;120(2):201-206. Epub 2017 Apr 27.

Division of Cardiology, Department of Internal Medicine, Busan Paik Hospital, Inje University College of Medicine, Busan, South Korea.

Although Asian people are believed to be more susceptible to bleeding on currently recommended dose of ticagrelor, there is limited evidence supporting low-dose ticagrelor. We prospectively randomized patients receiving dual antiplatelet therapy with aspirin and clopidogrel into 3 groups; aspirin plus clopidogrel 75 mg versus aspirin plus ticagrelor 90 mg once daily versus aspirin plus ticagrelor 45 mg twice daily. Platelet function assessments were conducted using VerifyNow P2Y12 assay at baseline and 28 days after randomization. No differences in baseline P2Y12 reaction unit (PRU) values were observed among the 3 groups. PRU values at the end of the treatment periods were significantly lower in low-dose ticagrelor (90 mg QD group, 98.6 ± 73.4 and 45 mg BID group, 65.5 ± 58.8) compared with clopidogrel (221.2 ± 50.1, both p <0.001). There was no significant difference in PRU values between 2 groups of low-dose ticagrelor (p = 0.208). The rates of high on-treatment platelet reactivity were significantly lower in low-dose ticagrelor compared with clopidogrel, whereas clopidogrel showed higher rate of optimal on-treatment platelet reactivity than ticagrelor 45 mg BID. However, similar rate of optimal on-treatment platelet reactivity was observed in clopidogrel and ticagrelor 90 mg QD. In conclusion, low-dose ticagrelor treatment, either with 90 mg QD or 45 mg BID, was associated with a more potent antiplatelet effect compared with clopidogrel treatment and once daily dose provided similar antiplatelet effect but favorable effect on optimal platelet inhibition compared with twice daily dose.
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July 2017

The Relationships between Body Mass Index and Left Ventricular Diastolic Function in a Structurally Normal Heart with Normal Ejection Fraction.

J Cardiovasc Ultrasound 2017 Mar 27;25(1):5-11. Epub 2017 Mar 27.

Division of Cardiology, Department of Internal Medicine, Busan Paik Hospital, Inje University, Busan, Korea.

Background: We conducted research to determine the effect of the weight on left ventricular (LV) diastolic function in Asians, who are at greater risk of cardiovascular events compared to individuals from Western countries with similar body mass indices (BMIs).

Methods: We studied 543 participants with structurally normal hearts and normal ejection fractions. Participants were classified as normal-weight (BMI < 23.0 kg/m), overweight (BMI 23.0-27.4 kg/m), or obese (BMI ≥ 27.5 kg/m). Peak E velocity, peak A velocity, and E' velocity were measured and E/E' was calculated.

Results: Overweight participants had lower E than normal-weight participants ( = 0.001). E' velocities in overweight and obese participants were less than those in normal weight participants (both < 0.001). The E/E' ratio in obese participants was higher compared to the value in normal-weight participants ( < 0.001) and overweight participants ( = 0.025). BMI was associated with E (R = -0.108), A (R = 0.123), E' (R = -0.229), and E/E' ratio (R = 0.138) (all < 0.05). In multivariate analyses, BMI was independently associated with higher A, lower E', and higher E/E'. The risk of diastolic dysfunction was significantly higher among overweight [adjusted odds ratio: 2.088; 95% confidence interval (CI): 1.348-3.235; = 0.001] and obese participants (adjusted odds ratio: 5.910; 95% CI: 2.871-12.162; < 0.001) compared to normal-weight participants.

Conclusion: Obesity and overweight independently predicted diastolic dysfunction. An optimal body weight lower than the universal cut-off is reasonable for preventing LV heart failure in Asians.
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March 2017

The efficacy and safety of co-administration of fimasartan and rosuvastatin to patients with hypertension and dyslipidemia.

BMC Pharmacol Toxicol 2017 01 5;18(1). Epub 2017 Jan 5.

Division of Cardiology, Korea University Guro Hospital, 148, Gurodong-ro, Guro-gu, Seoul, 08308, Republic of Korea.

Background: Hypertension and dyslipidemia are major risk factors of cardiovascular disease (CVD) events. The objective of this study was to evaluate the efficacy and safety of the co-administration of fimasartan and rosuvastatin in patients with hypertension and hypercholesterolemia.

Methods: We conducted a randomized double-blind and parallel-group trial. Patients who met eligible criteria after 4 weeks of therapeutic life change were randomly assigned to the following groups. 1) co-administration of fimasartan 120 mg/rosuvastatin 20 mg (FMS/RSV), 2) fimasartan 120 mg (FMS) alone 3) rosuvastatin 20 mg (RSV) alone. Drugs were administered once daily for 8 weeks.

Results: Of 140 randomized patients, 135 for whom efficacy data were available were analyzed. After 8 weeks of treatment, the FMS/RSV treatment group showed greater reductions in sitting systolic (siSBP) and diastolic (siDBP) blood pressures than those in the group receiving RSV alone (both p < 0.001). Reductions in siSBP and siDBP were not significantly different between the FMS/RSV and FMS alone groups (p = 0.500 and p = 0.734, respectively). After 8 weeks of treatment, FMS/RSV treatment showed greater efficacy in percentage reduction of low-density lipoprotein cholesterol (LDL-C) level from baseline than that shown by FMS alone treatment (p < 0.001). The response rates of siSBP with FMS/RSV, FMS alone, and RSV alone treatments were 65.22, 55.56, and 34.09%, respectively (FMS/RSV vs. RSV, p = 0.006). The LDL-C goal attainment rates with FMS/RSV, RSV alone, and FMS alone treatments were 80.43%, 81.82%, and 15.56%, respectively (FMS/RSV vs. FMS, p < 0.001). Incidence of adverse drug reactions with FMS/RSV treatment was 8.33%, which was similar to those associated with FMS and RSV alone treatments.

Conclusion: This study demonstrated that the co-administration of fimasartan and rosuvastatin to patients with both hypertension and hypercholesterolemia was efficacious and safe.

Trial Registration: Identifier: NCT02166814 . 16 June 2014.
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January 2017

Highly Durable Supportless Pt Hollow Spheres Designed for Enhanced Oxygen Transport in Cathode Catalyst Layers of Proton Exchange Membrane Fuel Cells.

ACS Appl Mater Interfaces 2016 Oct 10;8(41):27730-27739. Epub 2016 Oct 10.

Fuel Cell Laboratory, Korea Institute of Energy Research (KIER) , Daejeon, 305-343, Republic of Korea.

Supportless Pt catalysts have several advantages over conventional carbon-supported Pt catalysts in that they are not susceptible to carbon corrosion. However, the need for high Pt loadings in membrane electrode assemblies (MEAs) to achieve state-of-the-art fuel cell performance has limited their application in proton exchange membrane fuel cells. Herein, we report a new approach to the design of a supportless Pt catalyst in terms of catalyst layer architecture, which is crucial for fuel cell performance as it affects water management and oxygen transport in the catalyst layers. Large Pt hollow spheres (PtHSs) 100 nm in size were designed and prepared using a carbon template method. Despite their large size, the unique structure of the PtHSs, which are composed of a thin-layered shell of Pt nanoparticles (ca. 7 nm thick), exhibited a high surface area comparable to that of commercial Pt black (PtB). The PtHS structure also exhibited twice the durability of PtB after 2000 potential cycles (0-1.3 V, 50 mV/s). A MEA fabricated with PtHSs showed significant improvement in fuel cell performance compared to PtB-based MEAs at high current densities (>800 mA/cm). This was mainly due to the 2.7 times lower mass transport resistance in the PtHS-based catalyst layers compared to that in PtB, owing to the formation of macropores between the PtHSs and high porosity (90%) in the PtHS catalyst layers. The present study demonstrates a successful example of catalyst design in terms of catalyst layer architecture, which may be applied to a real fuel cell system.
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October 2016

Diagnostic Performance of Intravascular Ultrasound-Derived Minimal Lumen Area to Predict Functionally Significant Non-Left Main Coronary Artery Disease: a Meta-Analysis.

Korean Circ J 2016 Sep 28;46(5):622-631. Epub 2016 Sep 28.

Division of Cardiology, Busan Paik Hospital, University of Inje College of Medicine, Busan, Korea.

Background And Objectives: Intravascular ultrasound (IVUS)-guided percutaneous coronary intervention frequently results in unnecessary stenting due to the low positive predictive value of IVUS-derived minimal lumen area (MLA) for identification of functionally significant coronary stenosis. We appraised the diagnostic accuracy of IVUS-derived MLA compared with the fractional flow reserve (FFR) to assess intermediate coronary stenosis.

Subjects And Methods: We searched MEDLINE and Cochrane databases for studies using IVUS and FFR methods to establish the best MLA cut-off values to predict significant non-left main coronary artery stenosis. Summary estimates were obtained using a random-effects model.

Results: The 17 studies used in our analysis enrolled 3920 patients with 4267 lesions. The weighted overall mean MLA cut-off value was 2.58 mm. The pooled MLA sensitivity that predicted functionally significant coronary stenosis was 0.75 (confidence interval [CI]: 0.72 to 0.77) and the specificity was 0.66 (CI: 0.64 to 0.68). The positive likelihood ratio (LR) was 2.33 (CI: 2.06 to 2.63) and LR (-) was 0.33 (CI: 0.26 to 0.42). The pooled diagnostic odds ratio (DOR) was 7.53 (CI: 5.26 to 10.76) and the area under the summary receiver operating characteristic curve for all the trials was 0.782 with a Q point of 0.720. Meta-regression analysis demonstrated that an FFR cut-off point of 0.75 was associated with a four times higher diagnostic accuracy compared to that of 0.80 (relative DOR: 3.92; 95% CI: 1.25 to 12.34).

Conclusion: IVUS-derived MLA has limited diagnostic accuracy and needs careful interpretation to correlate with functionally significant non-left main coronary artery stenosis.
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September 2016

Initial Total Bilirubin and Clinical Outcome in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention With Drug-Eluting Stents.

Circ J 2016 May 28;80(6):1437-44. Epub 2016 Apr 28.

Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Busan Paik Hospital.

Background: Total bilirubin (TB) concentration is inversely associated with stable coronary artery disease, but there have been few studies on initial TB in patients with ST-segment elevation myocardial infarction (STEMI).

Methods and results: A total of 1,111 consecutive patients with STEMI undergoing primary percutaneous coronary intervention (PCI) with drug-eluting stents (DES) were divided into a high TB group (n=295) and a low TB group (n=816) according to the optimal cut-off 0.79 mg/dl. The high TB group had a higher rate of in-hospital major adverse cardiac events (MACE), a composite of cardiac death, non-fatal MI, and definite/probable stent thrombosis (14.2% vs. 4.2%, P<0.001) and cardiac death (13.9% vs. 3.9%, P<0.001) compared with the low TB group. The 30-day MACE-free survival rate was also significantly different between the groups (P<0.001, log-rank test). On multivariate Cox regression, initial high TB was a significant predictor of in-hospital MACE (HR, 2.69; 95% CI: 1.67-4.34, P=0.010) and of cardiac death (HR 2.72, 95% CI: 1.67-4.44, P=0.012). Adding initial TB to TIMI risk score significantly improved prediction for in-hospital MACE according to net reclassification improvement (NRI=5.2%, P=0.040) and integrated discrimination improvement (IDI=0.027, P=0.006).

Conclusions: Initial TB is a powerful prognostic marker, and inclusion of this can improve prediction of in-hospital MACE in patients with STEMI undergoing primary PCI with DES. (Circ J 2016; 80: 1437-1444).
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May 2016

Highly Platinum-Loaded Magnéli Phase Titanium Oxides as a High Voltage Tolerant Electrocatalyst for Polymer Electrolyte Fuel Cells.

J Nanosci Nanotechnol 2015 Sep;15(9):6988-94

Magnéli phase titanium oxides (MPTOs), possess high electrical conductivity and chemical stability, are promising support materials for the development of novel electrocatalyst in polymer electrolyte fuel cells (PEFCs). Despite MPTO's extremely low specific surface area (1 m2/g or less), high Pt loading (40 wt%) and excellent Pt particle-size distribution were obtained by the modified borohydride method. The reasons were discussed and compared with polyol method. Membrane electrode assembly (MEA) performance of those Pt/MPTO catalysts were found to be 169.7 and 366.2 mA/cm2 at 0.7 V for H2/air and H2/O2, respectively. The accelerated stress tests (ASTs) showed superior durability of the Pt/MPTO catalyst as a cathode electrode. After 10,000 cycles of high-voltage cycling test from 0.9 V and 1.3 V RHE, no significant performance degradation of the Pt/MPTO electrode was observed comparing with Pt/C. Thus, MPTOs can be considered as a good substitute of carbon supports in fuel cells.
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September 2015

Impact of Carvedilol versus β1-selective β blockers (bisoprolol, metoprolol, and nebivolol) in patients with acute myocardial infarction undergoing percutaneous coronary intervention.

Am J Cardiol 2015 Nov 31;116(10):1502-8. Epub 2015 Aug 31.

Division of Cardiology, Department of Internal Medicine, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea. Electronic address:

Although β blocker (BB) has constituted one of the mainstays of evidence-based therapy for patients with acute myocardial infarction (AMI), the comparative efficacy of different BBs remains uncertain. We sought to determine the comparative effectiveness of nonselective BB carvedilol and the most frequently prescribed β1-selective BBs (bisoprolol, metoprolol, and nebivolol) in patients with AMI undergoing percutaneous coronary intervention (PCI). A total of 7,863 patients were selected from the prospective national AMI registry, and patients were divided into carvedilol group (n = 6,231) and β1-selective BB group (n = 1,632) at hospital discharge. The primary end point was all-cause death or MI during follow-up. During a mean follow-up of 243 ± 144 days, all-cause death or MI occurred in 94 patients (1.5%) in the carvedilol group versus 31 patients (1.9%) in the β1-selective BB group (adjusted hazard ratio 0.81, 95% confidence interval 0.54 to 1.22, p = 0.32). This result was consistent across various risk subgroups. The risks of all-cause death, cardiac death, and MI were also similar between the groups. After propensity-score matching, no difference was observed in the rate of all-cause death or MI (1.7% in the carvedilol vs 1.9% in the β1-selective BB group, adjusted hazard ratio 0.84, 95% confidence interval 0.49 to 1.46, p = 0.55). In conclusion, no differences in the risk of all-cause death or MI were observed between the carvedilol and β1-selective BB groups in contemporary practice of the treatment for AMI.
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November 2015

The impact of calcium volume and distribution in aortic root injury related to balloon-expandable transcatheter aortic valve replacement.

J Cardiovasc Comput Tomogr 2015 Sep-Oct;9(5):382-92. Epub 2015 Apr 18.

St Paul's Hospital, Vancouver, Canada.

Background: A detailed assessment of calcium within the aortic root may provide important additional information regarding the risk of aortic root injury during transcatheter heart valve replacement (TAVR).

Objective: We sought to delineate the effect of calcium volume and distribution on aortic root injury during TAVR.

Methods: Thirty-three patients experiencing aortic root injury during TAVR with a balloon-expandable valve were compared with a control group of 153 consecutive TAVR patients without aortic root injury (as assessed by post-TAVR multidetector CT). Using commercial software to analyze contrast-enhanced pre-TAVR CT scans, calcium volume was determined in 3 regions: (1) the overall left ventricular outflow tract (LVOT), extending 10 mm down from the aortic annulus plane; (2) the upper LVOT, extending 2 mm down from the annulus plane; and (3) the aortic valve region.

Results: Calcium volumes in the upper LVOT (median, 29 vs 0 mm(3); P < .0001) and overall LVOT (median, 74 vs 3 mm(3); P = .0001) were higher in patients who experienced aortic root injury compared with the control group. Calcium in the aortic valve region did not differ between groups. Upper LVOT calcium volume was more predictive of aortic root injury than overall LVOT calcium volume (area under receiver operating curve [AUC], 0.78; 95% confidence interval, 0.69-0.86 vs AUC, 0.71; 95% confidence interval, 0.62-0.82; P = .010). Upper LVOT calcium below the noncoronary cusp was significantly more predictive of aortic root injury compared to calcium underneath the right coronary cusp or the left coronary cusp (AUC, 0.81 vs 0.68 vs 0.64). Prosthesis oversizing >20% (likelihood ratio test, P = .028) and redilatation (likelihood ratio test, P = .015) improved prediction of aortic root injury by upper LVOT calcium volume.

Conclusion: Calcification of the LVOT, especially in the upper LVOT, located below the noncoronary cusp and extending from the annular region, is predictive of aortic root injury during TAVR with a balloon-expandable valve.
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June 2016

The 24-Month Prognosis of Patients With Positive or Intermediate Results in the Intracoronary Ergonovine Provocation Test.

JACC Cardiovasc Interv 2015 Jun 20;8(7):914-23. Epub 2015 May 20.

Pyeongchon Sacred Heart Hospital, Hallym University, Anyang, South Korea.

Objectives: This study was an observational, multicenter registry to determine clinical characteristics and 24-month prognosis of patients who underwent intracoronary ergonovine provocation tests.

Background: The clinical characteristics and prognosis of patients who underwent the ergonovine provocation for vasospastic angina were not fully elucidated.

Methods: A total of 2,129 patients in the VA-KOREA (Vasospastic Angina in Korea) registry were classified into positive (n = 454), intermediate (n = 982), and negative (n = 693) groups by intracoronary ergonovine provocation tests. The 24-month incidences of cardiac death, new-onset arrhythmia, and acute coronary syndrome were determined (mean 26.7 ± 8.8 months).

Results: The number of smokers, frequency of angina before angiography, high-sensitivity C-reactive protein, and triglyceride were higher in the positive group than in other groups. The clinical characteristics of the intermediate and the negative groups were very similar. In the positive group, the incidences of diffuse, focal, and mixed spasm were 65.9%, 23.6%, and 10.6%. Coronary spasm was more frequently provoked on atherosclerotic segments. The 24-month incidences of cardiac death, arrhythmia, and acute coronary syndrome were low (0.9%, 1.6%, and 1.9%, respectively) in the positive group, and there was no cardiac death in the intermediate group (p = 0.02). In the positive group, frequent angina, current smoking, and multivessel spasm were independent predictors for adverse events.

Conclusions: The 24-month prognosis of the positive group in the intracoronary ergonovine provocation test was relatively worse than that of the intermediate group. More intensive clinical attention should be paid to vasospastic angina patients with high-risk factors including frequent angina before angiography, current smoking, and multivessel spasm.
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June 2015

Diagnostic accuracy and discrimination of ischemia by fractional flow reserve CT using a clinical use rule: results from the Determination of Fractional Flow Reserve by Anatomic Computed Tomographic Angiography study.

J Cardiovasc Comput Tomogr 2015 Mar-Apr;9(2):120-8. Epub 2015 Jan 21.

Department of Radiology, St Paul's Hospital, University of British Columbia, 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.

Background: Fractional flow reserve (FFR) is the gold standard for determining lesion-specific ischemia. Computed FFRCT derived from coronary CT angiography (coronary CTA) correlates well with invasive FFR and accurately differentiates between ischemia-producing and nonischemic lesions. The diagnostic performance of FFRCT when applied in a clinically relevant way to all vessels ≥ 2 mm in diameter stratified by sex and age has not been previously examined.

Methods: Two hundred fifty-two patients and 407 vessels underwent coronary CTA, FFRCT, invasive coronary angiography, and invasive FFR. FFRCT and FFR ≤ 0.80 were considered ischemic, whereas CT stenosis ≥ 50% was considered obstructive. The diagnostic performance of FFRCT was assessed following a prespecified clinical use rule which included all vessels ≥ 2 mm in diameter, not just those assessed by invasive FFR measurements. Stenoses <30% were assigned an FFR of 0.90, and stenoses >90% were assigned an FFR of 0.50. Diagnostic performance of FFRCT was stratified by vessel diameter, sex, and age.

Results: By FFR, ischemia was identified in 129 of 252 patients (51%) and in 151 of 407 vessels (31%). Mean age (± standard deviation) was 62.9 ± 9 years, and women were older (65.5 vs 61.9 years; P = .003). Per-patient diagnostic accuracy (83% vs 72%; P < .005) and specificity (54% vs 82%, P < .001) improved significantly after application of the clinical use tool. These were significantly improved over standard coronary CTA values before application of the clinical use rule. Discriminatory power of FFRCT also increased compared with baseline (area under the receiver operating characteristics curve [AUC]: 0.93 vs 0.81, P < .001). Diagnostic performance improved in both sexes with no significant differences between the sexes (AUC: 0.93 vs 0.90, P = .43). There were no differences in the discrimination of FFRCT after application of the clinical use rule when stratified by age ≥ 65 or <65 years (AUC: 0.95 vs 0.90, P = .10).

Conclusions: The diagnostic accuracy and discriminatory power of FFRCT improve significantly after the application of a clinical use rule which includes all clinically relevant vessels >2 mm in diameter. FFRCT has similar diagnostic accuracy and discriminatory power for ischemia detection in men and women irrespective of age using a cut point of 65 years.
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December 2015

Incidence and severity of paravalvular aortic regurgitation with multidetector computed tomography nominal area oversizing or undersizing after transcatheter heart valve replacement with the Sapien 3: a comparison with the Sapien XT.

JACC Cardiovasc Interv 2015 Mar;8(3):462-471

Department of Medical Imaging and Division of Cardiology, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address:

Objectives: This study sought to compare the influence of the extent of multidetector computed tomography (MDCT) area oversizing on the incidence of paravalvular aortic regurgitation (PAR) between the Sapien 3 and the Sapien XT transcatheter heart valve (THV) to define a new MDCT sizing guideline suitable for the Sapien 3 platform.

Background: The inverse relationship of PAR occurrence and oversizing has been demonstrated for the Sapien XT but the incidence of PAR with comparable oversizing with the Sapien 3 is not known.

Methods: Sixty-one prospectively enrolled patients who underwent transcatheter aortic valve replacement with the Sapien 3 THV were compared with 92 patients who underwent transcatheter aortic valve replacement with the Sapien XT THV. Patients were categorized depending on the degree of MDCT area oversizing percentage: undersizing (below 0%), 0% to 5%, 5% to 10%, and above 10%. The primary endpoint was mild or greater PAR on transthoracic echocardiography.

Results: Mild or greater PAR was present in 19.7% of patients (12 of 61) in the Sapien 3 group and in 54.3% of patients (50 of 92) in the Sapien XT group (p < 0.01). The Sapien 3 group, compared with the Sapien XT group, consistently demonstrated significantly lower rates of mild or greater PAR except for oversizing >10% (p for interaction = 0.54). Moderate or severe PAR rates were also lower in the Sapien 3 group than in the Sapien XT group (3.3% vs. 13.0%, p = 0.04). In the Sapien 3 group, a MDCT area oversizing percentage value of ≤4.17% was identified as the optimal cutoff value to discriminate patients with or without mild or greater PAR.

Conclusions: Our retrospective analysis suggests that the Sapien 3 THV displays significantly lower rates of PAR than does the Sapien XT THV. A lesser degree of MDCT area oversizing may be employed for this new balloon-expandable THV.
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March 2015