Hospital morbidity and mortality after myocardial revascularisation surgery: current changes in risk factors.

To identify the operating risks for mortality and morbidity in patients undergoing aortocoronary bypass surgery, the data of 514 myocardial revascularisation procedures performed consecutively between January 1991 and December 1992 were analysed; 73.2% of the patients had associated diseases and 59.3% had suffered one or more previous myocardial infarctions. The mean ejection fraction of the population as a whole was 52.2 +/- 13. In 10.5% of the cases there was severe left ventricular (LV) function impairment with a mean ejection fraction (EF) of 30.2 +/- 4.4 (range 20-35). A major preoperative complication occurred in 8.2% of the entire population and 68.8% of the patients undergoing emergency surgery. Surgery was elective in 72.7% of the cases, urgent in 15.4% and emergency in 11.9%. Hospital mortality was 4.1% (CL 3.2-4.9). In the group of electively operated patients, mortality was 2.7% (CL 1.8-3.5), with no statistically significant difference (P = 0.943) from the mortality observed in the patients undergoing urgent surgery [2.5% (CL 0.8-4.1)]. The mortality in both groups was statistically different (P = 0.0001 and P = 0.008) from that of the patients undergoing emergency surgery [14.7% (CL 10.1-18.9)]. Perioperative acute myocardial infarction occurred in 5.4% of the patients (CL 4.4-6.4), in three cases resulting in death [10.7% (CL 4.8-15.8)]. Fourteen of the acute myocardial infarctions (AMI) occurred in the 42 patients undergoing emergency surgery for acute coronary occlusion (33.3%). A percentage of 18.7% of the 493 surviving patients suffered a postoperative complication.(ABSTRACT TRUNCATED AT 250 WORDS)