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

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.