Incidence and Predictors of Sudden Cardiac Death After a Major Non-Fatal Cardiovascular Event

Abstract

Background: Sudden cardiac death (SCD) still accounts for the majority of deaths from the four major cardiovascular events (myocardial infarction (MI), heart failure (HF), atrial fibrillation (AF), and stroke) despite substantial progress on prevention.

Methods: Four separate cohorts (one for each of the four major cardiovascular conditions) were captured through person-linked hospital morbidity and mortality data collections between 2000 and 2009 and followed-up for 11.5 years. The incidence rate for each cohort was total SCD cases divided by sum of follow-up time for each individual alive. Kaplan-Meier survival curve was used to calculate unadjusted risk of SCD. Predictors of SCD were identified by fitting multivariable adjusted Cox regression models in each of the cohorts.

Results: There were 1,174 cases of SCD from 53,614 total CVD events across the cohorts (35.6% for MI, 15.6% for HF, 22.4% for AF, 26.4% for stroke). The incidence rate and unadjusted risk of SCD were both highest after incident hospitalisation for HF, followed by MI, stroke and AF. The elevated risk of SCD was independently associated with MI, HF, arrhythmias, peripheral artery disease, diabetes, chronic kidney disease, and prior coronary heart disease (hazard ratios ranging from 1.1 to 2.8). Early revascularisation is protective in 28-day survivors after an incident MI event.

Conclusions: An appreciable incidence of SCD following an incident event of MI, HF, AF and stroke deserves greater prevention efforts. Major medical conditions such as MI, HF, peripheral artery disease, and arrhythmias are risk markers of SCD and coronary revascularisation is protective.

Keywords: Incidence; Major cardiovascular event; Predictor; Sudden cardiac death.