Influence of left ventricular function and other parameters on early and late mortality following coronary bypass surgery.

Left ventricular performance, coronary anatomy and postoperative clinical parameters of 66 control patients (group 1) randomly selected from 797 survivors of coronary bypass surgery were compared with those of 45 patients who died within 30 days of operation (group II) and 53 patients who died late (average, 22+/-2 mo) (group III). Average preoperative left ventricular end-diastolic pressure, ejection fraction and mean circumferential fibre shortening rate were significantly better in group I than in group III patients. These same parameters were not significantly different when group I was compared to group II. Abnormal wall motion was significantly less frequent in patients from group I than in patients from group II and III. Triple-vessel disease was present preoperatively in 40 (61%) controls compared with 37 (82%) early deaths (P = 0.021) and 35 (66%) late deaths (NS). The number of grafts placed per patient was not significantly different in the three groups. Perioperative myocardial in farction (MI) and low cardiac output syndrome were the commonest causes of early death. Late complications such as MI and heart failure occurred in 4 (6%) v; 15 (32%) (P = 0.0006) and 4 (6%) v. 27 (57%) (Pless than 0.0001) group I v. group III patients, respectively. Surgical expertise, preoperative ventricular performance and triple-vessel disease are important determinants of early mortality following bypass surgery and preoperative left ventricular performance is one of the most important determinants of late mortality,