High risk for obstructive sleep apnea in patients with acute coronary syndrome: initial experience from a coronary unit

Introduction

Previous studies from outpatients suggested that obstructive sleep apnea (OSA) is associated with an increased risk for acute myocardial infarction and stroke. However, the evidence in inpatients is scanty. The main aim of the present study was to evaluate the risk for OSA in consecutive patients with acute coronary syndrome (ACS) admitted to a coronary unit.

Methods

We initially evaluated 94 newly diagnosed patients with ACS. All participants performed a clinical evaluation and questionnaires about the risk for OSA (Berlin questionnaire) and subjective daytime sleepiness (Epworth questionnaire). A total score >10 was considered excessive daytime sleepiness. A value of P < 0.05 was considered significant.

Results

Four patients refused to participate. Of the 90 patients (18 with unstable angina and 72 with myocardial infarction), the prevalence of high risk for OSA in patients with ACS was 58% (52 patients). Only four patients (7.7%) with high risk had a previous diagnosis of OSA. The mean age and body mass index were similar (P > 0.1) in patients with low and high risk for OSA (61 ± 14 vs 64 ± 12 years and 26.2 ± 3.7 vs 27.9 ± 7.0 kg/m², respectively). However, patients with high risk presented an increased subjective daytime sleepiness than patients with low risk for OSA (10 ± 6 vs 7 ± 4; P = 0.007).

Conclusion

High risk for OSA is common in consecutive patients with ACS but is frequently underdiagnosed and consequently undertreated. Future studies should be performed to evaluate the clinical impact of OSA in patients with ACS.