[Results after coronary bypass operation]

To determine the influence of various risk factors on 30-day postoperative mortality rate of aortocoronary bypass operation at different centres.

Data on 227 patients (179 men, mean age 63 [40-87] years; 48 women, mean age 68 [44-81] years), 219 first operations, 8 second operations) were retrospectively analysed. In all patients the indications for aortocoronary bypass surgery had been established in the last 3 months of 1993. The operations had been performed at six cardiac centres in Germany (five in Hessen [H1-H5]) and in three hospitals elsewhere in Europe outside of Germany (E1-E3).

The operative mortality was relatively high (5.3%), 152 patients (67%) presenting with one or more risk factors accounting for an increased perioperative mortality. The mortality rate was significantly higher for: clearly impaired left ventricular function (ejection fraction < 40%): 20 vs 3% with an ejection fraction > or = 40% (P < 0.001); emergency operation: 16.6 vs 2.7% for elective operation (P < 0.001); advanced age (> or = 70 years): 10.9 vs 3.1% for younger patients (P < 0.025); and unstable angina: 9.2 vs 2.9% with stable angina (P < 0.05). Most of the bypasses were done with the internal mammary artery (63.9%, usually combined with venous bypasses (exclusive use of venous bypasses in 35.2%), but the proportion of arterial bypasses differed greatly between centres (96% in H3, 19% in H4).

(1) Aortocoronary bypass operations are done on many patients with important risk factors, resulting in a relatively high 30-day postoperative mortality rate. (2) The proportion of internal mammary artery bypasses markedly differs between centres in Hessen.