Obstructive sleep apnoea is highly frequent in consecutive patients with refractory angina

Abstract

Purpose: Obstructive sleep apnoea (OSA) is common among patients with stable coronary artery disease and may contribute to poor cardiovascular outcome. OSA has not been investigated in patients with refractory angina, a debilitating condition characterized by persistent symptoms despite optimized medical therapy. Methods: Consecutive patients with multi-vessel coronary disease by angiography and refractory angina (severe ischemic symptoms that persist despite optimal medical therapy and whom coronary revascularization procedures are no longer feasible or helpful) were recruited from a specialized out patient clinic. Regardless of sleep complaints, all patients were evaluated by standard overnight polysomnography, symptoms of excessive daytime sleepiness by Epworth Sleepiness Scale (ESS) and one week diary of angina. Results: We evaluated 31 patients (18 males, age: 62±10y, body mass index: 29.8±4.5kg/m2). Co-morbidities were common (dyslipidemia 100%, hypertension 93% and diabetes 61%) and all patients presented persistent angina despite optimal anti-ischemic medical therapy and preserved systolic function (ejection fraction on echocardiography: 53±11%). Patients presented poor sleep quality, poor sleep efficiency (60±16%) and the prevalence of OSA (AHI>15) and severe OSA (AHI>30) was 71 and 55%, respectively. As compared with patients without OSA patients with OSA presented similar age, gender, BMI (28.2±5 vs. 30.4±4.5kg/m2, p=0.26) similar ESS (10±6 vs. 11±6), non-significant trend to higher frequency of diurnal (66 vs. 91%, p=0.13) and nocturnal angina (45 vs. 77%, p=0.10). Conclusions: This preliminary study showed a high frequency of OSA in consecutive patients with refractory angina. Traditional risk factors for OSA, including age, male gender and BMI did not discriminate patients with OSA. Non-significant trends to higher frequency of diurnal and nocturnal angina suggest that OSA may contribute to trigger angina symptoms.