Abstract Body (Do not enter title and authors here): Background
Coronary CT angiography (CCTA) has emerged as a first line tool for detecting CAD and assessing need for invasive coronary angiography (ICA). Historically, women have higher cardiovascular mortality compared to men with similar coronary plaque burden, yet remain undertreated. This study aims to investigate gender differences in ICA rates and subsequent revascularization following CCTA.

Methods
This study included adults who underwent CCTA between 2013-2019 at a single institution. CCTA stenosis severity was categorized as <50%, 50-69% and ≥70%. Plaque burden was assessed by segment involvement score (SIS), defined as number of coronary segments with plaque. Outcomes included ICA and revascularization within 90 days of CCTA. Multivariable logistic regression analysis was performed after adjustment for demographic, clinical, and imaging variables.

Results
Of 5,855 patients (mean age 61 years, 58% men) who underwent CCTA, 582 (9.9%) and 386 (6.6%) underwent ICA and revascularization, respectively. There was no significant difference in ICA rates between men and women with similar CCTA stenosis severity (Figure 1A; stenosis 50-69%: 17.9% vs. 19.2%, p=0.677; stenosis ≥70%: 53.8% vs. 58.3%: p=0.313). However, among patients with stenosis ≥70% who underwent ICA, men had significantly higher rates of revascularization (Figure 1A. 80.1% vs. 69.2%, p=0.029). In multivariable analysis, male gender was an independent predictor of revascularization after adjustment for clinical characteristics, including CCTA stenosis severity and SIS (male gender: OR 1.58, 95% CI: 1.01-2.47, p=0.047). Of note, in patients with stenosis ≥70%, rates of revascularization in women were significantly lower in the early study period (years 2013-2015, p=0.020); however, the difference narrowed in the recent study period (years 2016-2019, p=0.309) (Figure 1B).

Conclusion
There were comparable ICA rates between men and women. Women with severe stenosis (≥70%) by CCTA had significantly lower rates of revascularization, particularly in the early study period. These findings suggest a disparity in the management of CCTA-identified severe CAD, though it has demonstrated improvement in recent years.