Sex Differences in Functional and CT Angiography Testing in Patients With Suspected Coronary Artery Disease

Background: Although risk stratification is an important goal of cardiac noninvasive tests (NITs), few contemporary data exist on the prognostic value of different NITs according to patient sex.

Objectives: The goal of this study was to compare the results and prognostic information derived from anatomic versus stress testing in stable men and women with suspected coronary artery disease.

Methods: In 8,966 patients tested at randomization (4,500 to computed tomography angiography [CTA], 52% female; 4,466 to stress testing, 53% female), we assessed the relationship between sex and NIT results and between sex and a composite of death, myocardial infarction, or unstable angina hospitalization.

Results: In women, a positive CTA (≥70% stenosis) was less likely than a positive stress test result (8% vs. 12%; adjusted odds ratio: 0.67). Compared with negative test results, a positive CTA was more strongly associated with subsequent clinical events than a positive stress test result (CTA-adjusted hazard ratio of 5.86 vs. stress-adjusted hazard ratio of 2.27; adjusted p = 0.028). Men were more likely to have a positive CTA than a positive stress test result (16% vs. 14%; adjusted odds ratio: 1.23). Compared with negative test results, a positive CTA was less strongly associated with subsequent clinical events than a positive stress test result in men, although this difference was not statistically significant (adjusted p = 0.168). Negative CTA and stress test results were equally likely to predict an event in both sexes. A significant interaction between sex, NIT type, and test result (p = 0.01) suggests that sex and NIT type jointly influence the relationship between test result and clinical events.

Conclusions: The prognostic value of an NIT result varies according to test type and patient sex. Women seem to derive more prognostic information from a CTA, whereas men tend to derive similar prognostic value from both test types.