Chatterjee NA, et al. - Researchers performed this study in a current population of patients with coronary heart disease without severe systolic dysfunction to estimate the rate of sudden and/or arrhythmic deaths (SAD) vs other competing causes of death to detect high-risk subgroups that might be targeted in future trials of SAD prevention. A considerable proportion of overall mortality was attributed to SAD in this population. Unlike other markers that were equally related with both modes of death, moderately reduced left ventricular ejection fraction (LVEF), age and New York Heart Association (NYHA) class distinguished SAD and non-SAD. Across clinical subgroups, a significant variation in absolute and proportional risk of SAD was noted.

Methods

• Researchers performed this prospective observational cohort study at 135 clinical sites in the US and Canada, including 5,761 participants with coronary heart disease who did not qualify for primary prevention implantable cardioverter defibrillator therapy based on left ventricular ejection fraction (LVEF) of more than 35% or New York Heart Association (NYHA) heart failure class (LVEF >30%, NYHA I).
• Exposures included clinical risk factors measured at baseline including age, LVEF, and NYHA heart failure class.
• Main outcomes and measures included primary outcome of SAD, which is a composite of SAD and resuscitated ventricular fibrillation arrest.

Results

• The included cohort had mean (SD) age of 64 (11) years.
• During a median of 3.9 years, the estimated cumulative incidence of SAD and non-SAD was 2.1% and 7.7%, respectively.
• Most common mode of cardiovascular death was sudden and/or arrhythmic death, resulting in 114 of 202 cardiac deaths (56%), although the primary mode of death in this population was noncardiac death.
• The lowest 4-year cumulative incidence of SAD was reported in those with an LVEF of more than 60% (1.0%) and highest in those with an LVEF of 30% to 40% (4.9%) and class III/IV heart failure (5.1%); however, the cumulative incidence of non-SAD was similarly elevated in these latter high-risk subgroups.
• Death due to SAD was more likely to occur in patients with a moderately reduced LVEF (40%-49%), while those with class II heart failure and advancing age were more likely to die of non-SAD.
• A wide variation was seen in the proportion of deaths due to SAD, from 14% (18 of 131 deaths) in patients with NYHA II to 49% (37 of 76 deaths) in those younger than 60 years.