Sex differences in the effectiveness of early coronary computed tomographic angiography compared with standard emergency department evaluation for acute chest pain: the rule-out myocardial infarction with Computer-Assisted Tomography (ROMICAT)-II Trial.

Background: We evaluate sex-based differences in the effectiveness of early cardiac computed tomographic angiography (CCTA) and standard emergency department (ED) evaluation in patients with acute chest pain.

Methods And Results: In the Rule-Out Myocardial Infarction With Computer-Assisted Tomography (ROMICAT)-II multicenter, controlled trial, we randomized 1000 patients (47% women) 40 to 74 years of age with symptoms suggestive of acute coronary syndrome to an early CCTA or standard ED evaluation. In this prespecified analysis, women in the CCTA arm had a greater reduction in length of stay, lower hospital admission rates, and lesser increased cumulative radiation dose than men in a comparison of ED strategies (P for interaction ≤0.02). Although women had lower acute coronary syndrome rates than men (3% versus 12%; P<0.0001), sex differences in length of stay persisted after adjustment for baseline differences, including acute coronary syndrome rate (P for interaction <0.03). Length of stay was similar between sexes with normal CCTA findings (P=0.11). There was no missed acute coronary syndrome for either sex. No difference was observed in major adverse cardiac events between sexes and ED strategies (P for interaction =0.39). Women had more normal CCTA examinations than men (58% versus 37%; P<0.0001), less obstructive coronary disease by CCTA (5% versus 17%; P=0.0001), but similar normalcy rates for functional testing (P=0.65). Men in the CCTA arm had the highest rate of invasive coronary angiography (18%), whereas women had comparable low 5% rates regardless of ED strategy.

Conclusions: This trial provides data supporting an early CCTA strategy as an attractive option in women presenting to the ED with symptoms suggestive of acute coronary syndrome. The findings may be explained by lower CAD prevalence and severity in women than men.

Clinical Trial Registration Url: http://www.clinicaltrials.gov. Unique identifier: NCT01084239.