[Sleep-related breathing disorders in patients with coronary heart disease].

INTRODUCTION AND AIM OF STUDY

Obstructive sleep apnoea (OSA) favours the development of arterial hypertension independently of body-weight and may thus have an effect on coronary heart disease (CHD). This study was undertaken to determine the prevalence of OSA in patients with CHD.

PATIENTS AND METHODS

From among all patients in whom left heart catheterization with coronary angiography had provided the diagnosis of coronary heart disease 50 were randomly chosen (47 men, 3 women; mean age 61 +/- 6 years) for further investigations. During the night airway flow, heart rate, body position and arterial oxygen saturation were recorded. The patients also had to fill in a questionnaire concerning tiredness during the day and any snoring. Polysomnography was performed in all those whose apnoea index (AI) was > 10/h.

RESULTS

25 patients had an apnoea index of > 10/h. Eight of them also had increased tiredness during the day. The patients with an AI > 10/h were significantly older than those in whom it was < or = 10/h (63.1 +/- 3.5 vs 58.4 +/- 7.2 years; P < 0.002) and also had a higher body-mass index (27.8 +/- 4.2 vs 25.7 +/- 3.0 kg/m2; P < 0.05). Polysomnography, done in the sleep laboratory, in 19 of the 25 patients with an AI > 10/h registered an average AI of 17.0 +/- 10.9 per hour sleep; in seven patients it was > 20/h.

CONCLUSIONS

The prevalence of obstructive sleep apnoea (OSA) is higher in patients with coronary heart disease (CHD) than in the healthy population. As OSA associated with a marked fall in nocturnal blood oxygen saturation and a rise in blood pressure may cause myocardial ischaemia, OSA should also always be considered when CHD is diagnosed.