Differences of plaque burden measures on CCTA in younger men and women

• Semi-quantified measures of plaque burden by coronary CT angiography (CCTA) are associated with a higher risk of all-cause mortality; and all-cause mortality and nonfatal MI in younger women compared to men. • Greater risk stratification was observed in young women in all measured CCTA variables including the severity of coronary stenosis, measurements of plaque extent, extent and severity and CAC in comparison to men. • Whether these differences reflect biological factors or treatment differences remains to be determined. The extent and severity of coronary artery disease (CAD) on coronary CT angiography (CCTA) is predictive of mortality, cardiovascular death, and non-fatal myocardial infarction in both men and women; however, associations of various measures of coronary plaque burden with prognosis in younger women and men has had little study. To compare prognostic significance of CAD plaque burden and distribution on CCTA in women and men <60. 3813 consecutive patients (age: 49.4±8.1 years, 36% women) without CAD history who underwent CCTA (2007-2019) with clinical follow-up. Single academic medical center None CCTA plaque burden was assessed by stenosis severity, segment involvement score (SIS), segment stenosis score (SSS), and coronary artery calcium (CAC) scores. Primary endpoint: all-cause mortality (ACM); secondary outcome: ACM or non-fatal MI (NFMI). 180 (4.7%) ACM occurred over a median of 7.4 years, Severity of stenosis, SIS, SSS and extent of CAC were higher in men compared to women (all p<0.001). In multivariable Cox models, there were significant interactions between sex and all CCTA measures, with women having higher risk than men of ACM with increase of each plaque burden measure compared to men: coronary stenosis (CAD≥50% HR 6.52 vs 1.86, interaction p=0.021), SIS (SIS>4 HR 6.94 vs 1.68, interaction p=0.006), SSS (SSS>6 HR 7.91 vs 1.79, interaction p=0.006) and CAC (CAC>300 HR 9.62 vs 1.82, interaction p=0.004). All plaque burden measures discriminated events in women better than men, with C-statistics for multivariable models ranging from 0.729-0.760 in women, compared to 0.674-0.690 in men. Findings were similar for ACM/NFMI. Prognostic significance of multiple measures of plaque burden identified by CCTA had greater prognostic impact in younger women, compared with younger men. NA