Sex Differences in the Performance of Cardiac Computed Tomography Compared With Functional Testing in Evaluating Stable Chest Pain

In industrialized countries, coronary artery disease (CAD) is the leading cause of death among women and associated with a worse outcome compared with men. Because of a frequently different presentation of complaints, ischemic heart disease is thought to be under-recognized in women. The prevalence of vasospasm and microvascular angina is higher in women, which may partly explain the differences in symptoms between women and men. Conventional first-line noninvasive diagnostic tests are thought to be less accurate in women, further contributing to underdiagnosis and potentially undertreatment. On the other hand, women have higher rates of indeterminate exercise ECG results but also more falsepositive results because of nonspecific ST-T segment changes. The lower sensitivity of nuclear imaging is thought to result from the smaller size of the female heart, although falsepositive diagnoses may be introduced by breast attenuation artifacts. Paradoxically, there seems to be a relative overuse Background—Cardiac computed tomography (CT) represents an alternative diagnostic strategy for women with suspected coronary artery disease, with potential benefits in terms of effectiveness and cost-efficiency. Methods and Results—The CRESCENT trial (Calcium Imaging and Selective CT Angiography in Comparison to Functional Testing for Suspected Coronary Artery Disease) prospectively randomized 350 patients with stable angina (55% women; aged 55±10 years), mostly with an intermediate coronary artery disease probability, between cardiac CT and functional testing. The tiered cardiac CT protocol included a calcium scan followed by CT angiography if the Agatston calcium score was between 1 and 400. Patients with test-specific contraindications were not excluded from study participation. Sex differences were studied as a prespecified subanalysis. Enrolled women presented more frequently with atypical chest pain and had a lower pretest probability of coronary artery disease compared with men. Independently of these differences, cardiac CT led in both sexes to a fast final diagnosis when compared with functional testing, although the effect was larger in women (P interaction=0.01). The reduced need for further testing after CT, compared with functional testing, was most evident in women (P interaction=0.009). However, no sex interaction was observed with respect to changes in angina and quality of life, cumulative diagnostic costs, and applied radiation dose (all P interactions≥0.097). Conclusions—Cardiac CT is more efficient in women than in men in terms of time to reach the final diagnosis and downstream testing. However, overall clinical outcome showed no significant difference between women and men after 1 year. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01393028. (Circ Cardiovasc Imaging. 2017;10:e005295. DOI: 10.1161/CIRCIMAGING.116.005295.)