The cost-effectiveness of routine post myocardial infarction exercise stress testing

The cost-effectiveness of the strategy of a routine pre-discharge exercise test (followed by coronary angiography and coronary artery bypass surgery if indicated) in patients with an uncomplicated myocardial infarction was compared with a policy of no routine exercise testing. Using data from the literature, a decision tree was developed to estimate the number of lives saved by the routine exercise test strategy (12 lives saved per 1000 tests), as well as the number of angiograms and coronary artery bypass procedures that would be performed. It was assumed that surgery decreases one year mortality by 25%. The resources consumed by bypass surgery were obtained from a chart review and the costs were estimated using a method of fully allocated costing. Both direct and indirect costs were included. The average cost of coronary artery bypass surgery was $14,958 (1985 Canadian dollars). The cost of routine exercise testing was $255,726 per life saved. With sensitivity analyses this varied from $139,487 (coronary bypass surgery 50% effective) to $1,022,904 (bypass surgery 7.5% effective). A routine post myocardial infarction stress test is an example of how a relatively inexpensive technology, by leading to other expensive clinical actions, can consume a significant amount of resources.