Severe obstructive sleep apnea increases mortality in patients with ischemic heart disease and myocardial injury

Abstract

Objectives: We hypothesized that obstructive sleep apnea(OSA) has a dose-dependent impact on mortality in those with ischemic heart disease or previous myocardial injury.

Methods: We performed a retrospective cohort study of 281 consecutive OSA patients with a history of myocardial injury as determined by elevated troponin levels or with known existing ischemic heart disease. We compared survival between those with severe OSA [apnea–hypopneaindex (AHI) ≥30] and those with mild to moderate OSA(AHI >5 and <30).

Results: Of the 281 patients (mean age 65 years, mean BMI34, 98% male, 58% with diabetes), 151 patients had mild moderate OSA and 130 had severe OSA. During a mean follow-up of 4.1 years, there were significantly greater deaths in the severe OSA group compared to the mild moderate OSA group [53 deaths (41%) vs. 44 deaths(29%), respectively, p00.04]. The adjusted hazard ratio for mortality with severe OSA was 1.72 (95% confidence interval1.01–2.91, p00.04).

Conclusions: The severity of obstructive sleep apnea is associated with increased risk of death, and risk stratification based on OSA severity is relevant even in the diseased cardiac patient.