P1443 Sex differences of coronary physiology can be justified by fractional myocardial mass

Abstract

Abstract Background Women has lower prevalence of coronary artery disease but has higher mortality from acute myocardial infarction. The gender difference in the anatomical-physiological relationship may elucidate the gender difference in the clinical presentation of coronary artery disease. Purpose We hypothesized that the gender difference in the anatomical-physiological relationship may elucidate the gender difference in the clinical presentation of coronary artery disease. Background Women has lower prevalence of coronary artery disease but has higher mortality from acute myocardial infarction. The gender difference in the anatomical-physiological relationship may elucidate the gender difference in the clinical presentation of coronary artery disease. Methods In this multicenter registry, 482 patients who underwent coronary CT angiography and fractional flow reserve (FFR) measurement were enrolled. Fractional myocardial mass (FMM, a vessel-specific amount of myocardium) and %FMM (fraction of FMM to whole myocardial mass) was measured in major coronary arteries and branches. FFR and quantitative coronary angiography (QCA) were interrogated in the subset of 772 vessels. The severity of physiological or anatomical stenosis was assessed by FFR and diameter stenosis (DS), respectively. Results In the analysis of all major epicardial arteries (N = 3,833), FMM was lower in women compared to men (p < 0.01, all), but %FMM was similar between women and men (p = NS, all). Among physiologically assessed 772 vessels, compared to men (N = 587), vessels of women (N = 185) showed smaller dimension (reference diameter (RD) = 2.90 ± 0.65 vs 3.14 ± 0.69 mm, minimal luminal diameter (MLD) = 1.30±.0.57 vs 1.40 ± 0.57 mm (p < 0.05, all), similar severity of stenosis (DS = 55% vs 55% p = NS), and higher FFR (0.81 ± 0.13 vs 0.78 ± 0.15, p < 0.001). In subgroup analysis according to the tertiary categories of DS, RD, and MLD, vessels of women showed higher FFR and lower FMM. Generalized estimating equations modeling demonstrated that gender, DS, RD, MLD, and location in left anterior descending artery were not (p = NS, all) but FMM/MLD were significant predictors for FFR ≤ 0.80 (p = 0.021). Conclusions Compared to men, coronary arteries of women are smaller and supply smaller amount of myocardium even after adjusting for vessel size, which may explain overall higher FFR value of women. This gender difference in anatomical-physiological relationship may explain the gender difference in the clinical coronary artery disease. Abstract P1443 Figure.