Sex Bias in Considering Coronary Bypass Surgery

Abstract

Cardiovascular nuclear medicine exercise studies may serve as a screening method to be used in making decisions to refer patients for catheterization and coronary artery bypass surgery. In a study of 390 patients consecutively referred for nuclear exercise testing, abnormal results found in 31% of the women and in 64% of the men affected physicians' decisions to recommend catheterization in men only; 4% of the women with abnormal radionuclide scans were referred for catheterization compared with 40% of the men (p < 0.001). This 10:1 ratio was independent of age. A multiple logistic regression analysis that controlled for age, previous myocardial infarction, presence of typical and atypical angina, and abnormal test results yielded an odds ratio of 6.3 for men. The male-to-female ratio of patients with coronary artery disease given abnormal results of a cardiovascular nuclear scan is only 2:1. Thus, the sex differential in decisions to refer patients for cardiac catheterization cannot be explained entirely by differences in the sensitivity of tests or the rates of coronary artery disease; it also cannot be explained by differential benefits from surgery. These findings raise the question of whether coronary artery bypass surgery is underused in women.