In-hospital predictors for primary prevention of sudden death after acute myocardial infarction with cardiac dysfunction

Abstract

BackgroundCurrent guidelines recommend prophylactic defibrillator implantation in patients with acute myocardial infarction (AMI) and left ventricular ejection fraction (LVEF) ≤40 % or LVEF ≤35 % plus heart failure symptoms or inducible ventricular tachyarrhythmias during an electrophysiology study at 40 days after AMI or 90 days after revascularization. In-hospital predictors of sudden cardiac death (SCD) after AMI during the index hospitalization remain unsettled. We sought to examine in-hospital predictors of SCD in patients with AMI and LVEF ≤40 % evaluated during the index hospitalization. MethodsWe retrospectively evaluated 441 consecutive patients with AMI and LVEF ≤40 % admitted to our hospital between 2001 and 2014 (77 % male gender; median age: 70 years; median hospitalization length: 23 days). The primary endpoint was a composite of SCD or aborted SCD at ≥30 days after AMI onset (composite arrhythmic event). LVEF and QRS duration (QRSd) on electrocardiography were measured at a median of 12 days and 18 days, respectively. ResultsDuring a median follow-up of 7.6 years, the incidence of composite arrhythmic events was 7.3 % (32 of 441 patients). In multivariable analysis, QRSd ≥100 msec (beta-coefficient = 1.54, p = 0.003), LVEF ≤23 % (beta-coefficient = 1.14, p = 0.007), and onset-reperfusion time > 5.5 h (beta-coefficient = 1.16, p = 0.035) were independent predictors of composite arrhythmic events. The combination of these 3 factors was associated with the highest rate of composite arrhythmic events compared with 0–2 factors (p < 0.001). ConclusionsThe combination of QRSd ≥100 msec, LVEF ≤23 %, and onset-reperfusion time > 5.5 h during the index hospitalization provides precise risk stratification for SCD in patients early after AMI.