Obstructive sleep apnea affects hospital outcomes of patients with non-ST-elevation acute coronary syndromes.

STUDY OBJECTIVE

We aimed to test the hypothesis that clinically suspected obstructive sleep apnea (OSA) independently predicts worse in-hospital outcome in patients with non-ST elevation acute coronary syndromes.

DESIGN

At admission, individuals were evaluated for clinical probability of OSA by the Berlin Questionnaire. Primary cardiovascular endpoint was defined as the composite of death, nonfatal myocardial infarction, or refractory angina during hospitalization.

SETTING

Coronary care unit.

PATIENTS

There were 168 consecutive patients admitted with unstable angina or non-ST elevation acute myocardial infarction.

MEASUREMENTS AND RESULTS

During a median hospitalization of 8 days, the incidence of cardiovascular events was 13% (12 deaths, 4 nonfatal myocardial infarctions, and 6 refractory anginas.) Incidence of the primary endpoint was 18% in individuals with high probability of OSA, compared with no events in individuals with low probability (P = 0.002). After logistic regression adjustment for the Global Registry of Acute Coronary Events (GRACE) risk score, anatomic severity of coronary disease, and hospital treatment, probability of OSA remained an independent predictor of events (odds ratio [OR] = 3.4; 95% confidence interval [CI] = 1.3 - 9.0; P = 0.015). Prognostic discrimination of the GRACE score, measured by a C-statistic of 0.72 (95% CI = 0.59-0.85), was significantly improved to 0.82 (95% CI = 0.73-0.92) after inclusion of OSA probability in the predictive model (P = 0.03).

CONCLUSION

Considering the independent prognostic and incremental value of suspected OSA, this condition may represent an aggravating factor for patients with non-ST elevation acute coronary syndrome.