Mortality and morbidity of patients on the waiting list for coronary artery bypass graft surgery

Abstract

Objectives: The public health care system in Brazil has extensive waiting lists of patients requiring complex operations such as coronary artery bypass grafting (CABG). The purpose of this study was to identify the mortality and morbidity rates of the patients awaiting CABG and identify predictors of adverse events and their association with perioperative outcomes.

Methods: We conducted a retrospective analysis of outpatient medical records of patients referred for this elective procedure in Rio de Janeiro, Brazil. Excluded from the study were records of patients with any of the following: an indication for urgent surgery, unstable angina or concomitant surgical valvular disease or subsequent transfer to clinical or percutaneous therapy.

Results: A total of 274 patients were identified and met the inclusion criteria, with a median waiting time for an operation of 142.7 days. While waiting for CABG surgery, 31 (11.3%) patients died of any cause and 42 (15.3%) patients had a serious cardiac event (death, myocardial infarction or unstable angina). Of the 22 (8%) incidents of acute myocardial infarction, 8 (2.9%) were non-fatal and 14 (5.1%) were fatal. There was a greater risk of death awaiting CABG surgery in patients with a left ventricular ejection fraction below 45% (hazard ratio = 2.33, 95% confidence interval 1.02-5.32; P = 0.039). The operative mortality rate was 5.8%. Although there was no evidence of worse perioperative outcomes in patients with prolonged waiting times for an operation, there was an association between waiting more than 16 weeks for an operation and death while on the list.

Conclusions: Extensive waiting periods for CABG contribute to higher mortality and morbidity rates, especially in patients with left ventricular dysfunction.

Keywords: Coronary artery bypass surgery; Coronary disease; Myocardial revascularization; Waiting lists.