Joonghyun Ahn

Clopidogrel Versus Aspirin as an Antiplatelet Monotherapy After 12-Month Dual-Antiplatelet Therapy in the Era of Drug-Eluting Stents

Background—The use of dual-antiplatelet therapy (DAPT) exceeding 12 months may increase a bleeding risk despite a lower risk of ischemic events. There is no study to compare clinical outcomes in patients treated with a single-antiplatelet drug after DAPT in the era of drug-eluting stents (DES). We sought to investigate the efficacy and safety of clopidogrel versus aspirin monotherapy after 12-month DAPT after DES implantation using an institutional registry. Methods and Results—This observational study was conducted on consecutive patients receiving DES between January 2003 and December 2010. A total of 3243 patients receiving 12-month DAPT after DES implantation without adverse clinical outcomes were divided into 2 groups based on prescribed antiplatelet status: aspirin (n=2472) and clopidogrel (n=771). Clinical, angiographic, and procedural characteristics revealed more comorbidities and more complex lesions in the clopidogrel group than in the aspirin group. At 36 months after initiation of antiplatelet monotherapy, clopidogrel was associated with a reduction in risk for a composite of cardiac death, myocardial infarction, or stroke (aspirin versus clopidogrel; 3.8% versus 2.6%; hazard ratio, 0.54; 95% confidence interval, 0.32–0.92; P=0.02). The risk of cardiac death was lower with clopidogrel monotherapy than with aspirin monotherapy (1.4% versus 0.5%; hazard ratio, 0.31; 95% confidence interval, 0.11–0.93; P=0.04). Thrombolysis in myocardial infarction major bleeding occurred similarly between both groups (0.9% versus 1.3%; hazard ratio, 1.03; 95% confidence interval, 0.46–2.32; P=0.95). Conclusions—After 12-month DAPT, clopidogrel monotherapy, when compared with aspirin monotherapy, might be associated with a reduced risk of recurrent ischemic events in patients receiving DES.

Optimal Medical Therapy vs. Percutaneous Coronary Intervention for Patients With Coronary Chronic Total Occlusion - A Propensity-Matched Analysis.

BACKGROUND Limited data are available on the long-term clinical outcomes of coronary chronic total occlusion (CTO) patients who receive optimal medical therapy (OMT) compared with percutaneous coronary intervention (PCI). METHODS AND RESULTS Between March 2003 and February 2012, 2,024 patients with CTO were enrolled in a single-center registry. Among this patient group, we excluded CTO patients who underwent coronary artery bypass grafting and classified patients into the OMT group (n=664) or PCI group (n=883) according to initial treatment strategy. Propensity-score matching was also performed. The primary outcome was cardiac death. The median follow-up duration was 45.8 (interquartile range: 22.8-71.1) months. In the PCI group, 699 patients (79.2%) underwent successful revascularization. In the propensity-score matched population (533 pairs), there was no significant difference in the rate of cardiac death between the OMT and PCI groups (hazard ratio, 1.57; 95% confidence interval, 0.91-2.72, P=0.11). In the subgroup analysis, there were no significant interactions between the PCI strategy and cardiac death among several subgroups except that regarding collateral flow grades 0-2 vs. those with grade 3 (P=0.01). CONCLUSIONS As an initial treatment strategy, PCI did not reduce cardiac death compared with OMT for the treatment of CTO in the drug-eluting stent era.

Glycemic Control Status After Percutaneous Coronary Intervention and Long-Term Clinical Outcomes in Patients With Type 2 Diabetes Mellitus

Background— Data on the association between glycemic control after percutaneous coronary intervention and clinical outcomes are limited and controversial in diabetic patients. Methods and Results— We studied 980 patients with type 2 diabetes mellitus undergoing percutaneous coronary intervention using drug-eluting stents. Based on 2-year glycosylated hemoglobin A (HbA1c) levels, we divided patients into 2 groups of HbA1c<7.0 (n=489) and HbA1c≥7.0 (n=491). Propensity score–matched analysis was performed in 322 pairs. The primary outcome was major adverse cardiac and cerebrovascular events (MACCE), defined as a composite of cardiac death, myocardial infarction, repeat revascularization, or stroke. Median follow-up duration was 5.4 years. The 7-year incidence of MACCE was lower in the HbA1c<7.0 group than in the HbA1c≥7.0 group (26.9% versus 40.3%; adjusted hazard ratio, 0.75; 95% confidence interval, 0.57–0.98; P=0.03). After propensity score matching, the 7-year incidence of MACCE was still lower in the HbA1c<7.0 group than in the HbA1c≥7.0 group (27.5% versus 37.4%; hazard ratio, 0.71; 95% confidence interval, 0.52–0.97; P=0.03), mainly because of a reduction in repeat revascularization (19.9% versus 29.5%; hazard ratio, 0.66; 95% confidence interval, 0.47–0.93; P=0.02). In subgroup analyses, the benefit of glycemic control for MACCE was more prominent in patients with residual SYNTAX score (Synergy Between PCI With Taxus and Cardiac Surgery) >4 than in those with the residual SYNTAX score ⩽4 (Pinteraction=0.004). Conclusions— HbA1c<7.0 measured 2 years after percutaneous coronary intervention was associated with a reduced rate of MACCE. Our data suggest that high HbA1c levels 2 years after percutaneous coronary intervention may identify a population at increased risk of adverse events, especially repeat revascularization.

Additive prognostic values of NT-proBNP and exercise stress echocardiography in asymptomatic patients with degenerative mitral regurgitation and preserved left ventricular ejection fraction

BACKGROUND Exercise stress echocardiography (ESE) can be used to identify left ventricular (LV) dysfunction in asymptomatic chronic MR. NT-proBNP is the best marker for monitoring LV dysfunction. OBJECTIVE The aim of this study was to estimate the complementary prognostic value of ESE and NT-proBNP in asymptomatic degenerative MR with preserved LV ejection fraction (EF). METHODS Symptom-limited treadmill ESE was performed in 114 asymptomatic with significant degenerative MR (ERO >20mm, RV >30ml), LV end-systolic diameter <40mm and preserved LV function (EF >60%). Post-exercise EF increase of >4% was defined as contractile reserve (CR)+. RESULTS MV operation was performed in 19 (16.7%) and new-onset LV systolic dysfunction was developed in 23 (20.2%) patients over 3.5±1.5years. Based on ROC curve analysis, a NT-pro BNP of 100 was deemed the most relevant cutoff value to predict primary outcome with Youdens index=131.84. In sequential Cox models, a model based on clinical data and resting echocardiography variables (χ2=6.87) was improved by NT-proBNP (χ2=13.9) and presence of CR in ESE (χ2=20.8; p=0.0002). CONCLUSIONS In asymptomatic moderate to severe or severe degenerative MR and preserved LVEF, the presence of CR in ESE and NT-proBNP provide important incremental clinical determinants. In particular, the prognosis is markedly poor for those with high NT-proBNP but with absence of CR than low NT-proBNP with presence of CR.

Clinical implications of low-dose aspirin on vasospastic angina patients without significant coronary artery stenosis; a propensity score-matched analysis

BACKGROUND High-dose aspirin has been reported to exacerbate coronary artery spasm in patients with vasospastic angina. We investigated clinical implications of low-dose aspirin on vasospastic angina patients without significant coronary artery stenosis. METHODS We included patients without significant coronary artery stenosis on coronary angiography (CAG) and with positive results on intracoronary ergonovine provocation test between January 2003 and December 2014. A total of 777 patients were divided into two groups according to prescription of low-dose aspirin at discharge: aspirin group (n=321) and non-aspirin group (n=456). The major adverse cardiovascular events (MACE), defined as composite outcomes of cardiac death, acute myocardial infarction, revascularization, or rehospitalization requiring CAG or medication change due to recurrent angina were compared. RESULTS The aspirin group had significantly higher incidence of MACE (22.8% versus 12.1%; p=0.04) and had higher tendency for rehospitalization (20.6% versus 11.2%; p=0.08). All-cause mortality and cardiac death were similar between the two groups. After propensity score matching, the aspirin group had greater risk of MACE (hazard ratio [HR] 1.54; 95% confidence interval [CI], 1.04-2.28; p=0.037) and rehospitalization requiring CAG (HR, 1.33; 95% CI, 1.13-4.20; p=0.03), and a higher tendency for rehospitalization (HR, 1.40; 95% CI, 0.94-2.09; p=0.12). CONCLUSION In vasospastic angina without significant coronary artery stenosis, patients taking low-dose aspirin are at higher risk of MACE, driven primarily by tendency toward rehospitalization. Low-dose aspirin might be used with caution in vasospastic angina patients without significant coronary artery stenosis.

Morphine Does Not Affect Myocardial Salvage in ST-Segment Elevation Myocardial Infarction.

Recent studies have proposed intravenous (IV) morphine is associated with delayed action of antiplatelet agents in acute myocardial infarction. However, it is unknown whether morphine results in increased myocardial damage in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI). We investigated myocardial salvage index (MSI) to determine whether IV morphine affects myocardial injury adversely in STEMI patients undergoing primary PCI. 299 STEMI patients underwent contrast-enhanced magnetic resonance imaging a median of 3 days after PCI. Infarct size was measured on delayed-enhancement imaging, and area at risk was quantified on T2-weighted imaging. MSI was calculated as ‘[area at risk–infarct size] X 100 / area at risk’. IV morphine was administrated in 32.1% of patients. Patients treated with morphine had shorter symptom to balloon time and higher prevalence of Thrombolysis in Myocardial Infarction flow grade 0 or 1. The morphine group showed a trend toward larger MSI and infarct size and significantly greater area at risk than the non-morphine group. After propensity score matching (90 pairs), MSI was similar between the morphine and non-morphine group (46.1% versus 43.5%, P = .11), and infarct size and area at risk showed no difference. In propensity score-matched analysis, IV morphine prior to primary PCI in STEMI patients did not cause adverse impacts on myocardial salvage.

Clinical Significance of Reciprocal ST-Segment Changes in Patients With STEMI: A Cardiac Magnetic Resonance Imaging Study

INTRODUCTION AND OBJECTIVES We sought to determine the association of reciprocal change in the ST-segment with myocardial injury assessed by cardiac magnetic resonance (CMR) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). METHODS We performed CMR imaging in 244 patients who underwent primary PCI for their first STEMI; CMR was performed a median 3 days after primary PCI. The first electrocardiogram was analyzed, and patients were stratified according to the presence of reciprocal change. The primary outcome was infarct size measured by CMR. Secondary outcomes were area at risk and myocardial salvage index. RESULTS Patients with reciprocal change (n=133, 54.5%) had a lower incidence of anterior infarction (27.8% vs 71.2%, P < .001) and shorter symptom onset to balloon time (221.5±169.8 vs 289.7±337.3min, P=.042). Using a multiple linear regression model, we found that patients with reciprocal change had a larger area at risk (P=.002) and a greater myocardial salvage index (P=.04) than patients without reciprocal change. Consequently, myocardial infarct size was not significantly different between the 2 groups (P=.14). The rate of major adverse cardiovascular events, including all-cause death, myocardial infarction, and repeat coronary revascularization, was similar between the 2 groups after 2 years of follow-up (P=.92). CONCLUSIONS Reciprocal ST-segment change was associated with larger extent of ischemic myocardium at risk and more myocardial salvage but not with final infarct size or adverse clinical outcomes in STEMI patients undergoing primary PCI.

Risk Prediction Model of In-hospital Mortality in Patients With Myocardial Infarction Treated With Venoarterial Extracorporeal Membrane Oxygenation

INTRODUCTION AND OBJECTIVES There are limited data to develop a risk prediction model of in-hospital mortality for acute myocardial infarction (AMI) patients treated with venoarterial (VA)-extracorporeal membrane oxygenation (ECMO). We aimed to develop a risk prediction model for in-hospital mortality in patients with AMI who were treated with VA-ECMO. METHODS A total of 145 patients with AMI who underwent VA-ECMO between May 2004 and April 2016 were included from the Samsung Medical Center ECMO registry. The primary outcome was in-hospital mortality. To develop a new predictive scoring system, named the AMI-ECMO score, backward stepwise elimination and β coefficient-based scoring were used based on logistic regression analyses. The leave-one-out cross-validation method was performed for internal validation. RESULTS In-hospital mortality occurred in 69 patients (47.6%). On multivariable logistic regression analysis, the AMI-ECMO score comprised 6 pre-ECMO or angiographic parameters: age> 65 years, body mass index> 25 kg/m2, Glasgow coma score <6, lactic acid> 8 mmol/L, anterior wall infarction, and no or failed revascularization. The C-statistic value of AMI-ECMO score for predicting in-hospital mortality was 0.880 (95%CI, 0.820-0.940). The incidence of in-hospital mortality after VA-ECMO insertion was 6.2%, 28.1%, 51.6%, and 93.8% for AMI-ECMO score quartiles (0 to 16, 17 to 19, 20 to 26, and> 26), respectively (P <.001 for trend). The AMI-ECMO scores were also significantly associated with the estimated rate of all-cause mortality during follow-up (per 1 increase, HR, 1.11; 95%CI, 1.08-1.14; P <.001). CONCLUSIONS The AMI-ECMO score can help predict early prognosis in AMI patients who undergo VA-ECMO.

Staged hybrid procedure versus radiofrequency catheter ablation in the treatment of atrial fibrillation

The treatment effect of the hybrid procedure, consisting of a thoracoscopic ablation followed by an endocardial radiofrequency catheter ablation (RFCA), is unclear. A total of 117 ablation-naïve patients who underwent either the staged hybrid procedure (n = 72) or RFCA alone (n = 105) for drug-refractory, non-valvular persistent or long-standing persistent atrial fibrillation (AF) were enrolled. The primary outcome is occurrence of total atrial arrhythmia, defined as a composite of AF, sustained atrial tachycardia (AT), and atypical atrial flutter (AFL) after index procedure. The mean age was 52.7 years. Eighty-four percentage of the patients were male. Patients with prior history of stroke and long-standing persistent AF were more prevalent in the hybrid group than RFCA group. The left atrial volume index was larger in the hybrid group (P<0.001). During 2.1 years of median follow-up, the incidence of total atrial arrhythmia was not different between the two groups (32.5% vs. 35.7%; adjusted hazard ratio: 0.64; 95% confidence interval: 0.36–1.14; P = 0.13). The AF recurrence was significantly lower in the hybrid group than in the RFCA group (29.6% vs. 34.9%; adjusted HR: 0.53; 95% CI: 0.29–0.99; P = 0.046). The hospital stay was longer in the hybrid group than in the RFCA group (11 days vs. 4 days; P<0.001). A staged hybrid procedure may be an alternative choice for drug-refractory persistent AF, but it is no more effective than RFCA alone to eliminate atrial arrhythmias. Considering the long-length of stay and the morbidity, careful consideration should be given in selection of treatment strategy.

Impact of different nitrate therapies on long-term clinical outcomes of patients with vasospastic angina: A propensity score-matched analysis

BACKGROUND Despite the short-term vasodilatory effects of nitrates, the prognostic effects of long-term nitrate therapy in patients with vasospastic angina (VSA) remains unclear. We investigated the prognostic impact of chronic nitrate therapy in VSA patients. METHODS Between January 2003 and December 2014, a total of 1154 VSA patients proven by ergonovine provocation tests were classified into nitrate (n=676) and non-nitrate (n=478) groups according to prescriptions for oral nitrates, including isosorbide mononitrate (ISMN) and nicorandil. The primary outcome was major adverse cardiovascular events (MACE), defined as a composite of cardiac death, myocardial infarction, any revascularization, or rehospitalization due to recurrent angina. RESULTS The nitrate group was found to have a higher risk of MACE (22.9% vs. 17.6%, hazard ratio [HR] 1.32, 95% confidence interval [CI] 1.01-1.73, p=0.043) than the non-nitrate group. After propensity score matching, the nitrate group had greater risks of MACE (HR 1.32, 95%CI 1.01-1.73, p=0.049). Patients who received the immediate-release formula of ISMN (HR 1.80, 95%CI 1.35-2.39, p<0.001) or were administered any forms of ISMN other than at bedtime (HR 1.90, 95%CI 1.41-2.57, p<0.001) had a significantly higher risk of MACE compared with the non-nitrate group. Nicorandil was shown to have a neutral effect on VSA patients (HR 1.11, 95%CI 0.73-1.69, p=0.62). CONCLUSIONS The long-term use of nitrate therapy was associated with increased risk of adverse cardiac events in VSA patients. The use of immediate-release ISMN or the administration of ISMN other than at bedtime was related with poor outcomes of VSA patients.