Morbidity and mortality in patients waiting for coronary artery bypass surgery.

Objectives: To describe morbidity and mortality in patients waiting for coronary artery bypass graft (CABG) surgery and to assess determinants for the occurrence of these complications.

Methods: A prospective cohort study was carried out in a tertiary referral general teaching hospital. Three hundred and sixty consecutive patients with a priority of routine or urgent who were accepted for CABG or CABG with additional valve surgery were evaluated. Follow-up began from the moment of acceptance until the procedure took place for cardiac death, myocardial infarction and unstable angina requiring hospital admission.

Results: The median (25-75th percentile) waiting time in the two priority groups was 100 (79-119) days for the routine group and 69 (38-91) days for the urgent group. Overall, eight patients died, seven suffered a myocardial infarction, and 33 episodes of unstable angina requiring immediate hospitalization occurred. The majority of events took place during the first 30 days on the waiting list. Unstable angina less than 3 months before acceptance was identified as an independent predictor (hazard ratio 2.5, 95% confidence interval 1.2-5.1) for complications during the wait. The prognostic value of smoking and familial cardiovascular disease was found to vary depending on the priority assigned to the patient.

Conclusions: Complications occur relatively early during the time on the waiting list. If complications in coronary heart disease cannot be predicted more accurately, the only way to diminish the complication rate is drastic reduction of waiting times.