Clinical Impact of Implantable Cardioverter-Defibrillator Therapy and Mortality Prediction Model for Effective Primary Prevention in Korean Patients.

BACKGROUND: Studies on the efficacy of implantable cardioverter-defibrillator (ICD) therapy for primary prevention in Asian patients are relatively lacking compared to those for secondary prevention. Also, it is important to stratify which patients will benefit from ICD therapy for primary prevention. METHODS: Of 483 consecutive patients who received new implantation of ICD in 9 centers in Korea, 305 patients with reduced left ventricular systolic function and/or documented ventricular fibrillation/tachycardia were enrolled and divided into primary (n = 167) and secondary prevention groups (n = 138). RESULTS: During mean follow-up duration of 2.6 ± 1.6 years, appropriate ICD therapy occurred in 78 patients (25.6%), and appropriate ICD shock and anti-tachycardia pacing occurred in 15.1% and 15.1% of patients, respectively. Appropriate ICD shock rate was not different between the two groups (primary 12% vs. secondary 18.8%, P = 0.118). However, appropriate ICD therapy rate including shock and anti-tachycardia pacing was significantly higher (primary 18% vs. secondary 34.8%, P = 0.001) in the secondary prevention group. Type of prevention and etiology, appropriate and inappropriate ICD shock did not affect all-cause death. High levels of N-terminal pro-B-type natriuretic peptide, New York Heart Association functional class, low levels of estimated glomerular filtration ratio, and body mass index were associated with death before appropriate ICD shock in the primary prevention group. When patients were categorized in 5 risk score groups according to the sum of values defined by each cut-off level, significant differences in death rate before appropriate ICD shock were observed among risk 0 (0%), 1 (3.6%), 2 (3%), 3 (26.5%), and 4 (40%) (P < 0.001). CONCLUSION: In this multicenter regional registry, the frequency of appropriate ICD therapy is not low in the primary prevention group. In addition, combination of poor prognostic factors of heart failure is useful in risk stratification of patients who are not benefiting from ICD therapy for primary prevention.

Contemporary Status of Acute Myocardial Infarction in Korean Patients: Korean Registry of Acute Myocardial Infarction for Regional Cardiocerebrovascular Centers.

BACKGROUND: This study aimed to present the development process and characteristics of the Korean Registry of Acute Myocardial Infarction for Regional Cardiocerebrovascular Centers (KRAMI-RCC). METHODS: We developed KRAMI-RCC, a web-based registry for patients with AMI. Patients from 14 RCCs were registered for more than three years from July 2016. It includes an automatic error-checking system, and user training and on-site monitoring are performed to manage data quality. RESULTS: A total of 11,700 AMI patients were registered in KRAMI-RCC over three years (73.9% men). The proportions of patients with ST-elevation and non-ST-elevation myocardial infarction at discharge were 43.4% and 56.6%, respectively. Of the total three-year patients, 5.6% died in the hospital, and 4.4% died 12 months after discharge. The case fatality within 12 months was 9.7%. Pre-hospital care data showed delayed arrival time after onset of symptoms (median 153 min) and low transportation rate by public ambulance (25.2%). Post-hospital care data showed lower participation rate in the second rehabilitation program (16.8%). CONCLUSIONS: The recently developed KRAMI-RCC registry has been more focused on pre-hospital and post-hospital data, which will be helpful in understanding the current state of AMI disease management and in making policy decisions to reduce case fatality in Korea.

Effectiveness of Implantable Cardioverter-Defibrillator Therapy for Heart Failure Patients according to Ischemic or Non-Ischemic Etiology in Korea.

BACKGROUND AND OBJECTIVES: This study was performed to describe clinical characteristics of patients with left ventriculars (LV) dysfunction and implantable cardioverter-defibrillator (ICD), and to evaluate the effect of ICD therapy on survival in Yeongnam province of Korea. SUBJECTS AND METHODS: From a community-based device registry (9 centers, Yeongnam province, from November 1999 to September 2012), 146 patients with LV dysfunction and an ICD implanted for primary or secondary prophylaxis, were analyzed. The patients were divided into two groups, based on the etiology (73 with ischemic cardiomyopathy and 73 with non-ischemic cardiomyopathy), and indication for the device implantation (36 for primary prevention and 110 for secondary prevention). The cumulative first shock rate, all cause death, and type and mode of death, were determined according to the etiology and indication. RESULTS: Over a mean follow-up of 3.5 years, the overall ICD shock rate was about 39.0%. ICD shock therapy was significantly more frequent in the secondary prevention group (46.4% vs. 16.7%, p=0.002). The cumulative probability of a first appropriate shock was higher in the secondary prevention group (p=0.015). There was no significant difference in the all-cause death, cardiac death, and mode of death between the groups according to the etiology and indication. CONCLUSION: Studies from this multicenter regional registry data shows that in both ischemic and non-ischemic cardiomyopathy patients, the ICD shock therapy rate was higher in the secondary prevention group than primary prevention group.

Prognostic significance of simvastatin therapy in patients with ischemic heart failure who underwent percutaneous coronary intervention for acute myocardial infarction.

We prospectively followed 202 patients with ischemic heart failure who underwent percutaneous coronary intervention (PCI) for acute myocardial infarction (left ventricular [LV] ejection fraction <40%). Patients were divided into 2 groups: groups I (simvastatin group, n = 106, aged 60.8 +/- 10.3 years, men 71.7%) and II (non-simvastatin group, n = 96, aged 60.9 +/- 10.4 years, men 78.1%). During 1-year clinical follow-up, simvastatin therapy was associated with a significant reduction in mortality (1.9% vs 7.5%, p = 0.048), restenosis rate (25.7% vs 43.1%, p = 0.033), and repeat PCI rate (25.7% vs 43.1%, p = 0.033), and with significant improvement in LV ejection fraction (31% to 42% vs 32% to 39%, p = 0.042). The event-free survival rate was higher in group I than in group II (79.8% vs 57.0%, p = 0.001). In conclusion, simvastatin therapy improves LV systolic function and decreases mortality, restenosis, and repeat PCI rate in patients with ischemic heart failure who underwent PCI for acute myocardial infarction.

Characteristics of function-anatomy mismatch in patients with coronary artery disease.

BACKGROUND AND OBJECTIVES: Coronary lesions with mismatched functional and anatomical significance are not uncommon. We assessed the accuracy and predictors of mismatch between fractional flow reserve (FFR) and quantitative coronary angiography (QCA) analyses in patients with coronary lesions. SUBJECTS AND METHODS: A total of 643 lesions with pre-interventional FFR and QCA measurements were consecutively enrolled and divided into four groups using FFR ≤0.80 and percent diameter stenosis (%DS) ≥50% as cutoffs for functional and anatomical significance, respectively. Accordingly, FFR >0.80 and DS ≥50%, and FFR ≤0.80 and DS <50% defined false-positive (FP) and false-negative (FN) lesions, respectively. RESULTS: Overall, 40.4% (260/643) of the lesions were mismatched, and 51.7% (218/414) and 18.3% (42/229) were FP and FN lesions, respectively. In a multivariate analysis, independent predictors of FP were non-left anterior descending artery location {odds ratio (OR), 0.36; 95% confidence interval (CI), 0.28-0.56; p<0.001}, shorter lesion length (OR, 0.96; 95% CI, 0.95-0.98; p<0.001), multi-vessel disease (OR, 0.47; 95% CI, 0.30-0.75; p=0.001), and larger minimal lumen diameter by QCA (OR, 2.88; 95% CI,1.65-5.00; p<0.001). Independent predictors of FN were multi-vessel disease (OR, 1.82; 95% CI, 1.24-5.27; p=0.048), aging (OR, 0.96; 95% CI, 0.93-0.99; p=0.034), smoking (OR, 0.36; 95% CI, 0.14-0.93; p=0.034), and smaller reference vessel diameter by QCA (OR, 0.30; 95% CI, 0.10-0.87; p=0.026). CONCLUSION: A mismatch between FFR and angiographic lesion severity is not rare in patients with coronary artery disease; therefore, an angiography-guided evaluation could under- or over-estimate lesion severity in specific lesion subsets.

Left atrial volume index as a predictor for occurrence of atrial fibrillation after ablation of typical atrial flutter.

PURPOSE: Radiofrequency catheter ablation of the cavotricuspid isthmus (CTI) is effective in the treatment of typical atrial flutter (AFL) and atrial fibrillation (AF). AF and AFL often coexist. However, AF often occurs following successful ablation of CTI. The aim of this study was to investigate the predictors of concomitant AF following successful ablation of AFL. METHODS: We enrolled 122 patients [59.1 ± 11.3 years, male 100 (82.0%)] with typical AFL, who received successful ablation of the CTI. They were followed up at outpatient clinic (24.6 ± 25.7 months). Twelve-lead electrocardiogram and Holter monitoring were used to confirm the diagnosis of recurrent AFL or AF. We assessed prior history of AF, structural heart disease, left ventricular ejection fraction, left atrial diameter (LAD), left atrial volume index (LAVI), and AFL cycle length. RESULTS: Among the 122 ablated patients, 15 (12.3%) had recurrent AFL and 33 (27.0%) had recurrent AF. In univariate logistic analysis, LAD and LAVI could significantly predict the recurrence of AF after AFL ablation. However, multivariate logistic regression analysis found that the independent predictor of recurrent AF was LAVI. An LAVI of 42.6 mL may allow for the differentiation between only AFL and AFL with concomitant AF with 69.0% sensitivity and 69.8% specificity. CONCLUSIONS: LAVI might be a useful predictor for occurrence of AF after ablation of typical AFL.

A giant coronary artery aneurysm presenting with cardiac tamponade.

We report a case of giant coronary aneurysm presenting with cardiac tamponade, which was well documented with coronary angiography.

Impact of preinterventional arterial remodeling on in-stent neointimal hyperplasia and in-stent restenosis after coronary stent implantation.

BACKGROUND: Patterns of arterial remodeling during the course of plaque development have been shown to play an important role in both the progression of de novo atherosclerosis and in the restenotic process following coronary intervention. The aim of the present prospective study was to evaluate the effect of pre-interventional arterial remodeling on in-stent neointimal hyperplasia (NIH) and in-stent restenosis (ISR) after stenting. METHODS AND RESULTS: Pre-interventional arterial remodeling was assessed in 85 native coronary lesions by using intravascular ultrasound (IVUS). The remodeling index (RI) was 1.09+/-0.20 in the positive remodeling (PR)/intermediate remodeling (IR) group and 0.84+/-0.12 in the negative remodeling (NR) group. The plaque plus media cross sectional area (P&M CSA) at pre-intervention and NIH CSA at follow-up in the minimal lumen CSA were significantly larger in the PR/IR group (9.2+/-2.9 mm2 vs 6.2+/-1.8 mm2, 3.3+/-1.2 mm2 vs 1.5+/-0.9 mm2; p = 0.001, p = 0.001, respectively). On 3-dimensional analysis of IVUS images at follow-up, the lumen volume was significantly smaller in the PR/IR group than that in the NR group (62+/-15 mm3 vs 75 +/-20 mm3; p = 0.001), and neointima hyperplasia volume was significantly larger in the PR/IR group than that in the NR group (46+/-15 mm3 vs 26+/-10 mm3; p = 0.001). A significant positive correlation was found between pre-interventional RI and follow-up NIH CSA (r = 0.25, p = 0.022). The incidence of ISR and repeat intervention was significantly higher in the PR/IR group (30.8% vs 18.2%, 28.8% vs 15.2%; p = 0.032, 0.035, respectively). CONCLUSION: Measuring pre-interventional arterial remodeling patterns by IVUS may be helpful to stratify lesions at high-risk of ISR.

Effect of anti-oxidant (carvedilol and probucol) loaded stents in a porcine coronary restenosis model.

BACKGROUND: The long-term clinical efficacy of intracoronary stenting is limited by restenosis and delivery by the stent of agents inhibiting cell cycle progression should prevent in-stent neointimal hyperplasia. Carvedilol is an antioxidant that inhibits smooth muscle cell proliferation and migration, whereas probucol is a vascular protectant and reduces stent restenosis by improving the lumen dimension at the stent placement site. METHODS AND RESULTS: BiodivYsio phosphorylcholine-coated stents were dip-coated with carvedilol (5 mg/ml) or probucol (50 mg/ml) by immersion in respective methanol solutions. Twenty-four stents (carvedilol=8, probucol=8, control=8) were placed in 12 pigs and histopathologic analysis was done 4 weeks later. Histomorphometry of the carvedilol-coated stent group compared with the control groups showed that the neointimal area decreased by 42% (1.12+/-0.55 mm2 in the carvedilol group vs 1.92+/-0.52 mm2 in the control, p=0.004) and the lumen area increased by 20% (5.15+/-0.90 mm2 vs 4.17+/-0.87 mm2, p=0.008), resulting in a 43% reduction of the percent area stenosis (18.22+/-9.6% vs 31.9+/-9.2%, p=0.002). In the probucol-coated stent group, the lumen area, neointimal area, and %area stenosis did not different significantly from the control group. There were 7.7+/-2.97% proliferating nuclear cell antigen-positive cells in the carvedilol-coated stent group compared with 17.8+/-1.45% in the control group (p=0.0001) and 15.9+/-1.91% in the probucol group (vs control, p=NS). CONCLUSIONS: The carvedilol-coated stent, but not the probucol-coated one, inhibited neointimal hyperplasia in a porcine stent restenosis model.