Profile of preoperative characteristics of patients having CABG over the past decade.

The Society of Thoracic Surgeons' National Cardiac Database was used to determine the changes in preoperative characteristics and the predicted and observed risk of operative mortality of patients undergoing coronary artery bypass grafting during the decade of 1984 to 1993. During this period, the data show an increase of 2.5 years in age and decreases of 3% both in incidence of male patients and in incidence of first operation. There was little change in the percentages of urgent/emergent procedures or mean left ventricular ejection fraction. There was a significant 17.5% decrease in the proportion of lowest risk patients (0% to 2.5% predicted mortality) from 61.1% to 43.6%. Although no change in the next higher risk group (> 2.5% to 5.0% predicted mortality) occurred, the higher risk groups showed increases of 6.2%, 9.1%, 1.4%, and 1.1% for the > 5% to 10%, > 10% to 20%, > 20% to 30%, and > 30% to 50% risk groups, respectively. Over the past 2 years, there have been no significant changes in the distribution of the risk groups. These data will provide a base for comparison of future endeavors to lower complication rates and cost of coronary artery bypass graft operations.