Clinical characteristics of patients with acute coronary syndrome at high clinical suspicion for obstructive sleep apnea syndrome.

INTRODUCTION The risk of a cardiovascular event increases with the number of cardiovascular risk factors. The aim of this study was to identify patients with acute coronary syndromes (ACS) who were at high clinical suspicion for obstructive sleep apnea syndrome (OSAS). We also report the clinical characteristics of ACS patients at high clinical suspicion for OSAS. METHODS We studied 158 consecutive patients who satisfied the entry criteria (mean age 57.1 ± 8.7 years, 68% males) and were admitted to a tertiary university hospital. The risk of OSAS was assessed using the Berlin questionnaire. In addition, all patients were required to have excessive sleepiness as demonstrated by a score >10 on the Epworth Sleepiness Scale (ESS). RESULTS Fifty four (34.2%) patients were at high clinical suspicion. On admission, patients at clinical suspicion for OSAS had significantly more often a history of hypertension (92.6% vs. 55.8%, p<0.0001) or diabetes mellitus (37% vs. 15.4%, p=0.0049); significantly higher mean ESS (14.83 ± 3.02 vs. 5.83 ± 3.33, p<0.0001), systolic blood pressure (149.9 ± 34.2 vs. 128.4 ± 23.6 mmHg, p<0.0001), diastolic blood pressure (87.7 ± 17.4 vs. 76.2 ± 12.1 mmHg, p<0.0001), and body mass index (32.3 ± 4.6 vs. 27 ± 3.8 kg/m(2), p<0.0001); and a lower glomerular filtration rate (79.5 ± 21.2 vs. 87.5 ± 22.2 ml/min/1.73 m(2), p=0.048). Patients at high clinical suspicion for OSAS more often had onset of acute chest pain between midnight and 5.59 am compared to the patients at low clinical suspicion (42.6% vs. 26%; p<0.05). The mortality (7.4% vs. 1%; p=0.03) was greater in patients at high clinical suspicion. CONCLUSIONS This study demonstrates that one out of every three ACS patients was diagnosed with a high clinical suspicion for OSAS. The prevalence of cardiovascular risk factors among ACS patients at high clinical suspicion for OSAS was high when compared with patients at low clinical suspicion. This finding calls for physicians to perform routine screening and individual evaluation of myocardial infarction patients for sleep disorders, especially when they are obese, or have hypertension or chest pain in the night hours.