Determinants for early mortality in patients awaiting coronary artery bypass graft surgery: a case-control study

A total of 1124 consecutive patients who were selected for coronary artery bypass graft surgery were studied. Of patients awaiting surgery (mean waiting time 98 days) 25 patients (2.2%) died before operation (mean waiting time 63 days). To assess patient characteristics predictive for early mortality before surgery, 25 deceased patients were analysed and compared to 50 controls matched for age, gender, type of surgery and waiting-list priority. Univariate analysis showed that the deceased patients had a higher rate of severe angina pectoris class III-IV (odds ratio (OR) 2.9), unstable angina prior to angiography (OR 4.8), cardiac enlargement on chest X-ray (OR 13.5), positive exercise testing of short duration (less than or equal to 6 min) (OR 6.0), coumarin treatment (OR 4.2), smoking (OR 3.0), severe left main or three-vessel disease (OR 4.1), abnormal end-diastolic volume (OR 3.1) and an abnormal left ventricular wall motion score (OR 3.0). Using multivariate analysis, cardiac enlargement (OR 14.4), positive exercise testing of short duration (OR 13.3), smoking (OR 8.7), coumarin treatment (OR 7.1), unstable angina (OR 6.5) and/or left main or three-vessel disease (OR 5.4) were independent predictors for death while awaiting coronary revascularisation. Thus, patients with the above mentioned independent characteristics have an increased short-term mortality while awaiting coronary bypass graft surgery. These indicators may contribute important information for determination of priority in high risk patients awaiting coronary artery bypass graft surgery.