Objective: To determine the incidence of sudden cardiac death (SCD) according to left ventricular ejection fraction (LVEF) in survivors of myocardial infarction (MI) in the primary percutaneous coronary intervention (PCI) era.
Design: A multicentre observational prospective registered cohort study.
Setting: 18 medical centres in Japan.
Patients: 4122 consecutive patients (mean age 66 (SD 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 categorised into three groups: LVEF >40% (n = 3416), LVEF < or =40% and >30% (n = 507) and LVEF < or =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 < or =30% and LVEF < or =40% and >30% were at increased risk for SCD (HR 5.99, 95% CI 2.73 to 13.14, p<0.001, HR 3.37, 95% CI 1.74 to 6.50, p<0.001, respectively), and mortality (HR 3.85, 95% CI 2.96 to 5.00, p<0.001, HR 2.06, 95% CI 1.66 to 2.57, p<0.001, respectively), compared to patients with LVEF >40%. Kaplan-Meier estimates of SCD in patients with LVEF < or =30% were 2.9%, 5.1% and 5.1% at 1, 3 and 5 years, respectively.
Conclusion: There is a low incidence of SCD in survivors of MI in the primary PCI era, although LVEF is a predictor of increased risk for SCD.