Is obstructive sleep apnea (OSA) a risk factor for myocardial infarction and cardiac arrhythmias in patients with coronary heart disease (CHD)?

We prospectively studied 74 men, 39-78 years of age, with significant (greater than or equal to 70%) stenosis of one or more coronary arteries. The investigation included coronary arteriography, ventriculography, and ambulatory monitoring of cardio-respiratory variables during sleep using the MESAM-IV(TM). We found 48 subjects with a respiratory disturbance index (RDI)greater than or equal to 10 events per hour. Our analyses failed to establish a relationship between RDI, myocardial infarction and known risk factors for coronary heart disease. Similarly, there was no relationship between RDI, number of coronary vessels involved, or left ventricular ejection fraction. Compared to general population studies, however, our group of coronary heart disease patients had a high incidence of obstructive sleep apnea syndrome (35%).