[Main coronary artery stenosis: significance of the clinical stage for angiographic and surgical risk].

86 patients with significant main coronary artery stenosis (greater than 50%) were divided into 61 with stable and 25 with unstable angina pectoris. The coronary morphology (isolated main coronary artery stenosis, degree of stenosis, additional vessel disease) and the left ventricular function (ejection fraction, left ventricular end-diastolic pressure) were the same in both groups. Deaths due to coronary angiography amounted to 2.3% and involved two patients with unstable angina. 82% (n = 50) of the patients with stable angina and 83% (n = 19) with unstable angina were considered operable. 69% of the stable and 74% of the unstable group were actually revascularised. Operative deaths amounted to 3.4% and again involved two patients with unstable angina. During an average post-operative follow-up period of 38 months 5% of the operated and 28% of the non-operated patients died (P less than 0.05). The investigation demonstrated that for patients with main coronary artery stenosis operability in stable angina is no different from that in unstable angina. Angiographic and operative deaths in patients with unstable symptomatology, however, were markedly higher than in those with stable angina.