Results:

A total of 1,000 participants were included in this study; of those in the CCTA arm, 239 were women and 262 were men. There were no differences in the baseline characteristics between the two randomized arms (early CCTA vs. standard ED evaluation). However, overall, women were older, more frequently African American, more often diabetic, and were more likely to be on beta-blocker medications. Women had lower rates of ACS as a final diagnosis compared to men (3% vs. 12%, p < 0.0001). Women randomized to early CCTA had greater reduction in length of stay, lower hospital admission rates, and lesser increased cumulative radiation dose than men when comparing ED strategies (p-interactions ≤ 0.02). Women had lower ACS rates than men (3% vs. 12%, p < 0.0001); however, sex differences in length of stay persisted after adjustment for baseline differences including ACS rate (p interaction < 0.03). Length of stay was similar between sexes with normal CCTA findings (p = 0.11). There was no missed ACS for either sex. No difference was observed in major adverse cardiac events between sex and ED strategies (p-interaction = 0.39). Women had more normal CCTA examinations than men (58% vs. 37%, p < 0.0001), less obstructive coronary disease by CCTA (5% vs. 17%, p = 0.0001), but similar normalcy rates for functional testing (p = 1.0). Men in the CCTA arm had the highest rate of invasive coronary angiography (18%), while women had comparable low 5% rates irrespective of ED strategies.