Cost-effectiveness of screening strategies for left main coronary artery disease in patients with stable angina.

To define optimal strategies for screening for left main coronary artery disease (LMCAD), the authors evaluated the cost-effectiveness of exercise tolerance testing and cardiac catheterization in patients with mild stable chest pain, such as patients with definite or probable angina in the Coronary Artery Surgery Study registry (prevalence of LMCAD = 9%). Performance characteristics of the exercise test, operative mortality, long-term survival rates, and rates of crossing over to surgical therapy for patients initially managed with medical therapy were derived from pooled literature data; cost estimates were based on local charge data. Strategies using the exercise test to identify candidates for catheterization were associated with longer life expectancies than either the conservative strategy in which patients would be observed or the more aggressive strategy in which all patients would undergo coronary angiography. The most cost-effective option was to screen patients with an exercise test and to perform catheterization in patients with greater than or equal to 2 mm of ST-segment change. Compared with a strategy of catheterization for greater than or equal to 3 mm of ST-segment change only, this strategy increased life expectancy at marginal costs per year of life saved ranging from $11,263 to $18,100 for 40- to 70-year-old patients, respectively, while, compared with a strategy of observation unless symptoms worsened, its incremental cost-effectiveness was $6,510 to $12,428 per year of life saved. Thus, screening patients with stable chest pain syndromes with exercise tests and performing catheterization for patients with greater than or equal to 2 mm of ST-segment change has cost-effectiveness comparable to that of the treatment of moderate diastolic hypertension.