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

Abstract

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.

Keywords: coronary artery disease; imaging; noninvasive testing; prognosis; risk stratification.

Figure 1. Adjusted Association Between Noninvasive Test Type and Test Results in Women and Men Tested as Randomized

Adjusted for age, race, body mass index, coronary artery disease (CAD) equivalent, Framingham risk score (12), ASCVD score (13), 2011 Diamond and Forrester score (14), hypertension, dyslipidemia, diabetes, family history of premature CAD, sedentary lifestyle, smoking, typicality of chest pain, and physician's estimation of likelihood of significant CAD. CTA = computed tomographic angiography; ECG = electrocardiography.

Figure 2. Comparison of Test Results and Clinical Event Rates by Test Type in Women and Men

Clinical event rates are the primary composite outcome consisting of all-cause death, myocardial infarction, or unstable angina hospitalization. The top 2 panels compare positive test rates and event rates by sex in patients undergoing CTA vs. stress testing. In women event rates are similar in the 2 arms, but test positivity rates are higher in the stress test arm. In men event rates are also similar in the 2 arms, but test positivity rates are higher in the CTA arm. The bottom 2 panels compare event rates by positive and negative test results for each sex and by test type. Within women, the event rate with a negative CTA was similar to that with a negative stress test, but the event rate with a positive CTA was higher than that with a positive stress test. Within men, the event rate with a negative CTA was similar to that with a negative stress test, as was the event rate with a positive CTA and a positive stress test.

Figure 3. Adjusted Event Curves of the Primary Composite Outcome Comparing Positive Versus Negative Test Results by Sex and Test Type

Event curves are shown comparing the association of positive and negative test results for each sex and by test type with the primary composite outcome of all-cause death, myocardial infarction, or unstable angina hospitalization. Curve are adjusted for age, race, body mass index, coronary artery disease (CAD) equivalent, Framingham risk score (12), ASCVD score (13), 2011 Diamond and Forrester score (14), hypertension, dyslipidemia, diabetes, family history of premature CAD, sedentary lifestyle, smoking, typicality of chest pain, and physician's estimation of likelihood of significant CAD . Interaction p = 0.010. CTA = computed tomographic angiography.