Sleep Duration and Mortality in Patients With Coronary Artery Disease

Abstract

Extremes in sleep duration are associated with higher cardiovascular risk in the general population, but their impact in patients with documented coronary artery disease (CAD) remains unknown and potentially of clinical significance. We hypothesized that both short and long sleep duration are associated with higher mortality in CAD. We inquired about sleep durations in 2,846 patients enrolled in the Emory Cardiovascular Biobank (mean age 64 years, 38% female, 23% Black, and 82% with obstructive CAD, defined by positive coronary angiography), who were then followed for all-cause and cardiovascular mortality. Multivariate Cox proportional hazard models were calculated to examine the association of sleep duration and mortality. Sleep durations of <6.5 hours (short), ≥6.5 to <7.5 hours (normal), and ≥7.5 hours (long) were reported by 39%, 26% and 35% of the cohort, respectively. On follow-up (median 2.8 years), mortality rates were 15%, 11%, and 17%, respectively. After adjusting for demographics and risk factors, both short and long sleep duration were associated with higher all-cause mortality (hazard ratio 1.44, 95% confidence interval [1.10 to 1.89], and 1.41 [1.08 to 1.85], respectively). A similar pattern was demonstrated for cardiovascular mortality only for short (hazard ratio 1.48 [1.05 to 2.09]), but not long sleep duration. In conclusion, in patients with frank CAD, both short and long sleep duration were independently associated with higher all-cause mortality, and short sleep was independently associated with higher cardiovascular mortality. In conclusion, our study is the first to extend the observations of sleep duration and mortality from population-based studies to patients with documented cardiac disease.