Frequency of obstructive sleep apnoea syndrome detected by means of a questionnaire in patients with coronary heart disease.

As previous studies have suggested an association between obstructive sleep apnea syndrome (OSA) and ischaemic heart disease, the aim of the present study was to evaluate the frequency of clinically relevant OSA in this selected population. From September 1992 to April 1993, 136 patients referred to the Cardiology Unit for suspected angina pectoris were asked to participate in the study. The main inclusion criterion was a stable coronary heart disease, diagnosed by angiography. A sleep questionnaire was administered by a trained physician. Patients who experienced one of the following symptoms: association of body mass index (-weight/height2) above 27.5 and heavy snoring, breathing stops, or daytime hypersomnolence, were selected for a nocturnal oxygen saturation recording. The occurrence of at least one desaturation, defined as a 4% fall from baseline, led to a full night-time polysomnography. One hundred and eight patients (78 males), satisfied the entry criteria. A pulse oximetry was performed in 15, and three patients experienced a significant desaturation. Finally, one patient satisfied the criteria of OSA. The estimated proportion of OSA amounted to 0.92%, in accordance with the prevalence of OSA described in the general population. Clinically relevant OSA does not appear to be more frequent in patients suffering from stable coronary heart disease. Systematic sleep investigations in such patients do not appear to be useful in daily clinical practice.