Screening for obstructive sleep apnea in early outpatient cardiac rehabilitation: feasibility and results

Obstructive sleep apnea (OSA) has been recognized as a risk factor for cardiovascular disease and mortality. The aim of this study was to determine the feasibility and efficacy of implementing a screening program for OSA in early outpatient cardiac rehabilitation (CR) and to estimate the risk for OSA in this population.

From 535 consecutive patients enrolled in early outpatient CR we screened 383 (72%) patients and classified them as low- vs. high-risk for OSA using the Berlin questionnaire. Those considered at high-risk for OSA were referred for further evaluation. We assessed the yield and feasibility of the screening program, patient compliance with referral, and the percentage of patients diagnosed with OSA after polysomnography.

Mean age was 63 ± 12 years, 70% were men, 20% had diabetes, 65% had hypertension, and 58% had experienced a recent myocardial infarction. Two hundred and one patients (52%) had a high risk for OSA based on the questionnaire. Of the 169 who completed the CR program, only 111 (78%) were referred for further evaluation (Fig. 1). Of the 74 patients who completed their OSA work-up, 39 were found to have OSA with an apnea-hypopnea index of ≥ 5 events/h.

Implementation of a simple screening program for OSA in early outpatient CR is feasible with minimal incremental resources. A significant percentage of patients at high-risk decline further evaluation, suggesting that their perceived risk for OSA and its consequences may be low.