Abstract

Objective: To determine the incidence of sudden cardiac death (SCD) according to left ventricular ejection fraction (LVEF) in post myocardial infarction (MI) survivors in the primary percutaneous coronary intervention (PCI) era.

Design: A multicenter observational prospective registered cohort study.

Setting: Reduced LVEF is currently the best available predictor of SCD in MI survivors. Early revascularization, such as primary PCI, reduces mortality in acute MI patients.

Patients: 4,122 consecutive patients (mean age 66+12 years, 73.7% male) with acute MI, who were discharged alive.

Main outcome measures: The primary end point was SCD, and a secondary end point was death from any cause.

Results: Patients were categorized into 3 groups: LVEF>40% (n=3416), LVEF≤40% and >30% (n=507) and LVEF≤30% (n=199). Among all patients, 77.8% received PCI and 3.7% received coronary artery bypass graft surgery. During an average follow-up of 4.1 years, SCD was 1.2% and mortality was 13.1% . Patients with LVEF≤30% and LVEF≤40% and >30% were at increased risk for SCD (HR 5.99, 95% CI: 2.73-13.14, P<0.001, HR 3.37, 95% CI: 1.74-6.50, P<0.001, respectively), and mortality (HR 3.85, 95% CI: 2.96-5.00, P<0.001, HR 1.66, 95% CI: 1.66-2.57, P<0.001, respectively), compared to patients with LVEF>40%. Kaplan-Meier estimates of SCD in our patients with LVEF≤30% were 2.9%, 5.1% and 5.1% at 1, 3 and 5 years, respectively.

Conclusions: There is a low incidence of SCD in post MI survivors in the primary PCI era although LVEF is a predictor of increased risk for SCD.