Correlation Of Coronary Microvascular Function And Diastolic Dysfunction

Abstract Background Coronary microvascular dysfunction (CMD) is an important mechanism for heart failure with preserved ejection fraction (HFpEF) which is closely related with diastolic dysfunction on transthoracic echocardiography (TTE). Purpose The aim of this study was to evaluate the association of CMD with echocardiographic parameters of diastolic dysfunction. Methods Total 385 patients with chest discomfort in the absence of significant coronary artery obstruction were enrolled to this study and underwent invasive coronary physiologic assessment including index of microcirculatory resistance (IMR), and coronary flow reserve (CFR). Echocardiographic parameters for diastolic dysfunction - left atrial volume index (LAVI) and left ventricular filling pressure (E over e') were compared in patients with true CMD (CFR<2.5 with IMR ≥20), mismatched CMD (CFR≥2.5 with IMR ≥20 or CFR<2.5 with IMR <20), and no CMD (CFR≥2.5 with IMR <20). Results Among the study population, 55 patients (14.3%) were true CMD, 162 patients (42.1%) were mismatched CMD and 168 patients (43.6%) were no CMD. Age (62.9±10.5 vs. 61.1±9.9 vs. 61.7±10.5, p=0.522) and left ventricular ejection fraction (63.9±8.1 vs. 63.9±6.2 vs. 63.0±6.7, p=0.414) was not different between groups. Patients with true CMD showed significantly larger left atrial size (LAVI: 34.7±18.2 mL/m2 vs. 26.8±10.7 mL/m2, p=0.005) and trend towards higher LV filling pressure (E/e': 10.8±3.5 vs. 9.9±3.5, p=0.073) compared with no CMD. In subgroup analysis, younger patients showed more pronounced increase of LAVI (Age <65: 39.6±22.6 vs. 26.1±11.6, p=0.003; Age ≥65: 28.0±9.13 vs. 28.8±8.2, p=0.266; p for interaction 0.043) in true CMD compared to no CMD. Non-diabetic patients also showed more pronounced increase of E/e' in true CMD (Non-diabetes: 10.2±2.7 vs. 9.2±2.6, p=0.002; Diabetes: 12.1±4.5 vs. 11.9±5.1, p=0.197; p for interaction 0.015). Conclusions Coronary microvascular dysfunction is significantly related with echocardiographic parameters of diastolic dysfunction. The effect of CMD on diastolic dysfunction is more prominent in low-risk patients. Figure 1 Funding Acknowledgement Type of funding source: None