Changing Operative Characteristics of Patients Undergoing Operations for Coronary Artery Disease: Impact on Early Outcomes

Background Aggressive nonsurgical revascularization results in high-risk patients presenting for operation at a later stage of coronary artery disease (CAD). This study investigated the effect of temporal changes in operative characteristics on outcomes of surgical revascularization. Methods We compared preoperative, intraoperative, and postoperative variables of 5633 patients who underwent surgical revascularization for CAD between April 1998 and January 2007, divided into early (1998 to 2002, n = 2746) and late (2004 to 2007, n = 2887) eras. End points were major adverse outcomes (postoperative myocardial infarction, stroke, new dialysis) and operative mortality. Results Median age (66 vs 68 years, p < 0.0001), prevalence of left ventricular systolic dysfunction, left main stem disease, prior angioplasty, diabetes mellitus, concomitant valve operation, and aprotinin use increased steadily over time. Severe symptoms, nonelective operations, mean number of grafts, postoperative bleeding, reopening for bleeding, and blood transfusion declined. Major complications were evenly distributed between the eras. Operative mortality for isolated coronary artery bypass grafting did not change (2.0% vs 1.8% p = 0.62) despite increasing operative risk (p < 0.0001); there was a 100% reduction in the absolute risk (110% to 210%) over time. The markers for operative difficulties, such as longer bypass times, were determinants of operative mortality and, in addition to other predictors like age and left ventricular systolic dysfunction, were more prevalent in the late era. Conclusions Coronary operations are increasingly performed in higher-risk patients; however, surgical revascularization is nearly twice as safe in current practice compared with a decade ago.