Sex differences in coronary microvascular resistance measured by a computational fluid dynamics model

Abstract

BackgroundIncreased coronary microvascular resistance (CMVR) is associated with coronary microvascular dysfunction (CMD). Although CMD is more common in women, sex-specific differences in CMVR have not been demonstrated previously.AimTo compare CMVR between men and women being investigated for chest pain.Methods and resultsWe used a computational fluid dynamics (CFD) model of human coronary physiology to calculate absolute CMVR based on invasive coronary angiographic images and pressures in 203 coronary arteries from 144 individual patients. CMVR was significantly higher in women than men (860 [650–1,205] vs. 680 [520–865] WU, Z = −2.24, p = 0.025). None of the other major subgroup comparisons yielded any differences in CMVR.ConclusionCMVR was significantly higher in women compared with men. These sex-specific differences may help to explain the increased prevalence of CMD in women.

Coronary Spasm Testing with Acetylcholine: A Powerful Tool for a Personalized Therapy of Coronary Vasomotor Disorders

“…All these findings supported the hypothesis that women have elevated resting coronary blood flow, which, in turn, results in reduced capacity of coronary flow augmentation from rest to hyperemia [ 94 , 98 , 99 , 100 ]. Conversely, a computational fluid dynamics analysis by Taylor et al noted higher coronary microvascular resistance in women compared with men [ 101 ]. Differences in enrolled population (the study by Taylor et al [ 101 ] included a large proportion of patients with obstructive CAD, while the other studies included only patients with INOCA/ANOCA [ 94 , 98 , 99 , 100 ]), and invasive methods for assessing microvascular function might explain these differences.…”

“…Conversely, a computational fluid dynamics analysis by Taylor et al noted higher coronary microvascular resistance in women compared with men [ 101 ]. Differences in enrolled population (the study by Taylor et al [ 101 ] included a large proportion of patients with obstructive CAD, while the other studies included only patients with INOCA/ANOCA [ 94 , 98 , 99 , 100 ]), and invasive methods for assessing microvascular function might explain these differences. Furthermore, microvascular spasm is associated with a higher prevalence of diastolic dysfunction [ 102 , 103 , 104 ], a hallmark of heart failure with preserved ejection fraction, potentially suggesting a role in its pathogenesis [ 105 , 106 ].…”