Third coronary artery bypass operations: risks and costs.

BACKGROUND: Third coronary artery bypass operations are technically difficult and are associated with increased risk. METHODS: We reviewed the cases of 469 patients who had undergone a third isolated coronary artery bypass operation and used univariate and multivariate testing to examine the effect of preoperative and operative variables on outcome and costs. RESULTS: The in-hospital mortality was 7.0% (33 patients). Advanced age and severe symptoms were found to increase risk (both p < 0.05): the mortality was 14% (n = 74) in patients 70 years old or older who had severe symptoms. However, the overall mortality for 1993 through 1995 was 4.3% (5/117) and only one death (1.3%) occurred among the 79 patients who were less than 70 years old. The late survival rate was 94%, 84%, and 66% at 1, 5, and 10 postoperative years, respectively, and predictors of decreased late survival were advanced age, abnormal left ventricular function, and diabetes (all p < 0.05). Again, age of 70 years or more was a predictor of a poor outcome. Only 52% of patients in that subgroup (including both early and late mortality) were alive 5 years after operation. Analysis of direct hospital costs showed that the mean costs of third coronary artery bypass operations were 21% higher than the mean costs of primary operations but that the elevation in the mean costs for third operations was related to very high costs in 4 patients. Sex was found to influence the cost of both primary and third operations (increased cost for women). CONCLUSIONS: Unfavorable outcomes after third coronary artery bypass operations have been associated with preoperatively definable variables, particularly age of 70 years or more. The in-hospital mortality in patients younger than 70 was low, and long-term survival in this group has been favorable. The increased hospital costs associated with third operations are related to high costs in only a few patients and have been unpredictable.