Trends in Coronary Artery Bypass Surgery: Changing Type of Surgical Patient

Introduction and objectives. In the last few years, the percentage of high-risk patients proceeding to coronary artery bypass surgery has increased. The most common risk factors are older age and the presence of comorbid complaints. We carried out a retrospective study to confirm this new risk profile and to evaluate its impact on surgical results. Patients and method. We analyzed the changing risk profile of 1360 patients who underwent coronary artery bypass surgery in our hospital between 1993 and 2001, divided into three historical cohorts: 1993-1996, 1997-1999 and 2000-2001. The main factors associated with morbidity and mortality were analyzed by logistic regression analysis. The introduction of new operative techniques, such as off-pump surgery and arterial grafting, was also evaluated. Results. The patients' risk profile worsened over time: patients were older, comorbid complaints were more common, and ventricular function was poorer. EuroSCORE figures reflected this trend: estimated mortality in the three historical cohorts was 2.0%, 4.0% and 4.2%, respectively (P<.001). However, risk-adjusted mortality, at 3.7%, 2.7% and 1.5%, respectively, decreased (P<.05), and combined overall morbidity and mortality remained stable, at 16.7%, 16.4% and 13.8%, respectively, (P<.39). There was a non-significant tendency for arterial grafting and off-pump surgery to reduce in-hospital morbidity and mortality. Conclusions. The risk profile of patients undergoing surgery has worsened as their mean age has increased and as comorbid complaints have become more prevalent. However, there has been no simultaneous increase in risk-adjusted mortality. The potential benefits of new surgical advances such as off-pump surgery and multiple arterial grafting must be corroborated by future studies.