Reduced Left Ventricular Ejection Fraction Is a Risk for Sudden Cardiac Death in the Early Period After Hospital Discharge in Patients With Acute Myocardial Infarction.

BACKGROUND: The incidence of sudden cardiac death (SCD) after discharge in Japanese acute myocardial infarction (AMI) patients with reduced left ventricular ejection fraction (LVEF) treated with primary percutaneous coronary intervention (PCI) remains unknown.Methods and Results:The study population included 1,429 AMI patients (199 with LVEF ≤35% and 1,230 with LVEF >35%) admitted to the Hirosaki University Hospital, treated with primary PCI within 12 h after onset, and survived to discharge. LVEF was evaluated in all patients before discharge, and the patients were followed up for a mean of 2.6±0.8 years. The Kaplan-Meier survival curves revealed LVEF ≤35% was associated with all-cause death and SCD. The incidence of SCD was 2.6% at 1 year and 3.1% at 3 years in patients with LVEF ≤35%, whereas it was 0.1% at 1 year and 0.3% at 3 years in patients with LVEF >35%. Sixty-seven percent of SCDs in patients with LVEF ≤35% occurred within 4 months after discharge, and the events became less frequent after this period. A Cox proportional hazard model indicated LVEF ≤35% as an independent predictor for all-cause death and SCD. CONCLUSIONS: The incidence of SCD was relatively low in Japanese AMI patients treated with primary PCI, even in patients with LVEF ≤35% upon discharge. Careful management of patients with reduced LVEF is required to prevent SCD, especially in the early phase after discharge.

Potential roles of the wearable cardioverter-defibrillator in acute phase care of patients at high risk of sudden cardiac death: A single-center Japanese experience.

BACKGROUND: The wearable cardioverter-defibrillator (WCD) has been expected to play a role as an effective bridge therapy to implantable cardioverter-defibrillator (ICD) implantation in patients at high risk of ventricular tachyarrhythmias (VA). Although WCD has been available since April 2014 in Japan, its usefulness remains unclear. METHODS AND RESULTS: During the early period after hospitalization, patients at high risk of VA after excluding some elderly patients were prescribed WCD. The consecutive 50 patients with WCD use (median age 56 years, 38 for secondary prevention) were studied. We analyzed clinical efficacy and safety of WCD, and examined its potential roles. Of the 50 patients, 38 used WCD only during hospitalization. During WCD use [median 16 (IQR 8-33) days], all patients wore WCD for 98% of a day regardless of in or out-of-hospital use. Sustained VA was detected in 4 patients (8%; for primary prevention in 1) with 7 episodes, and 6 of 7 episodes required shock therapy. Of the 6 shock therapies, 4 were for sustained ventricular tachycardia with the median rate of 236beats/min (IQR 203-250), and the other 2 for ventricular fibrillation. Subsequently, only 27 patients (54%) of all underwent ICD implantation following the WCD use, because of reduced risk of VA after optimal pharmacological therapy or improvement in the left ventricular function. CONCLUSIONS: The WCD use for the acute phase care of patients at high risk of VA can be safe and effective, and may be useful for evaluating indication of ICD implantation.