Changing trends in emergency coronary bypass surgery

Patients undergoing emergency coronary artery bypass grafting represent a unique and high-risk population that remains challenging for cardiac surgeons. We examined the changing trends in patients undergoing emergency bypass grafting over the past 20 years.

We conducted a retrospective review of our database between 1990 and 2009 and patients were divided into 2 groups based on year of operation: 1990-1999, n = 393; 2000-2009, n = 184. The primary outcomes of interest for this study are operative mortality and incidence of low cardiac output syndrome.

The percentage of patients undergoing emergency coronary bypass grafting has decreased from 2.7% to 1.7% over time. The percentage of patients with dyslipidemia, hypertension, triple vessel disease, peripheral vascular disease, and left main disease increased over time (P < .05). Operative mortality remained at 8.1% in both year groups. Preoperative hypertension, congestive heart failure, left ventricular ejection fraction less than 20%, and previous cardiac surgery independently predicted operative mortality by logistic regression analysis. Low cardiac output syndrome developed in 25% of the patient population undergoing emergency bypass grafting. The independent predictors of low cardiac output syndrome were small body surface area, congestive heart failure, shock, myocardial infarction, earlier decade (1990-1999) and increased age.

Despite a changing preoperative risk profile, the operative mortality of emergency coronary artery bypass grafting has remained stable over the years. However, mortality remains significantly above the observed mortality in elective bypass grafting. Continued improvements in the management of heart failure and the care of the elderly will likely result in reduced risks of emergency coronary artery bypass grafting.