Current status of primary prevention of sudden cardiac death with implantable cardioverter defibrillator in patients with chronic heart failure--a report from the CHART-2 Study.

BACKGROUND The current status of primary prevention of sudden cardiac death (SCD) with implantable cardioverter defibrillator (ICD) in patients with heart failure with reduced ejection fraction remains to be fully elucidated in Japan. METHODS AND RESULTS In the chronic heart failure (CHF) cohort study, the CHART-2 Study, we enrolled 2,778 consecutive patients with NYHA class II-III. According to the Japanese Circulation Society guideline of prophylactic ICD, we divided them into 3 groups: group A, class I indication; B, class IIa; and C, no indication. During the (median) 3.2-year follow-up, 79 fatal arrhythmic events (FAE), defined as composite of sudden cardiac/arrhythmic death, ventricular tachycardia/fibrillation and appropriate ICD therapy, occurred. In the groups A, B and C, the prevalence of FAE was 16.1%, 8.9% and 1.9%, respectively; the use of prophylactic ICD among those with FAE, however, was only 44%, 9% and 6%, respectively. In the groups A and B combined, chronic atrial fibrillation (cAF) and left ventricular end-diastolic dimension (LVDd) ≥ 65 mm were independent predictors of FAE, and, when combined, their prognostic impact was highly significant (hazard ratio, 7.01; P<0.001). CONCLUSIONS Primary prevention of SCD with ICD in CHF patients is validated but is still underused in Japan, and the combination of cAF and LVDd ≥ 65 mm may be a useful indication of prophylactic ICD implantation.