The influence of age on the results of reoperative coronary artery bypass grafting

Abstract

Background: With a steady increase in the number of elderly patients requiring coronary artery bypass grafting (CABG), a larger portion of elderly patients will also become candidates for reoperative CABG. Scepticism still exists as to whether this operation is justified in older patients. The purpose of this study was to examine the effect of increasing age on the outcome after reoperative CABG.

Methods: Between January 1, 1990 and June 30, 1996 563 patients underwent isolated reoperative CABG, and were included in this retrospective analysis. Patients who had combined procedures were excluded. The patients were divided by age into two groups: those aged 69 years or less (n = 507), and those older than 70 years (n = 56). Hospital mortality and morbidity for each group was compared. Medium-term survival for each group was compared with that of their age-matched population derived from Swiss life tables.

Results: The patients aged 70 years and older had a higher New York Health Association functional class, and more patients had unstable angina requiring urgent surgery than did the younger patients. The elderly also showed an over-representation of diabetes and multifocal vascular disease (generalized arteriosclerotic disease), and there was a higher number of patients with triple-vessel disease and left stenosis (> or = 70%) in this group. Patients aged 70 years and older received fewer distal anastomoses (3.0 versus 3.6; P < 0.01), and had a longer cardiopulmonary bypass time compared with the younger patients, but the ischemia time was similar in both groups. Hospital mortality was higher in patients older than 70 years (7.1 versus 17.9%). There was an increased frequency of postoperative low cardiac output and a higher incidence of gastrointestinal complications and transient renal failure amongst the elderly patients (> or = 70 years). Despite a higher hospital mortality rate and slightly increased morbidity the 5-year survival was excellent, and comparable with the age-matched population in both groups [89.6% (< 70 years) and 76.2% (> or = 70 years)]. The cardiac event-free survival was 79.8% (< 70 years), and 69.9% (> or = 70 years) after 5 years.

Conclusion: An acceptable early mortality and long-term survival together with good functional long-term results support the justification of reoperative CABG in older patients, at least up to the age of 80 years.