Original Article
Coronary microvascular resistance and its relevant factors in patients with moderate coronary stenosis and chest pain
Dongfang He, Meiyan Liu, Lijun Zhang, Chengjun Guo, Yunpeng Chi, Lin Zhao, Xiaojiang Zhang
Published 2018-04-01
Cite as Chin J Intern Med, 2018, 57(4): 270-274. DOI: 10.3760/cma.j.issn.0578-1426.2018.04.008
Abstract
ObjectiveTo evaluate the impact of cardiovascular risk factors on index of microvascular resistance (IMR) and coronary flow reserve (CFR) and to explore the characteristics of IMR and CFR and the relationship between IMR and angiographic features in patients with intermediate coronary stenosis and chest pain.
MethodsFractional flow reserve (FFR), CFR, and IMR were measured in patients who underwent invasive coronary angiography with 40%-70% stenosis by visual assessment. All patients with FFR>0.75 were enrolled and grouped with the cut-off points of IMR≥25 and CFR≤2.0. Patients with IMR≥25 were group H, including two sub-groups (high IMR-low CFR, group H1 and high IMR-high CFR, group H2), while those with IMR<25 were group N. The thrombolysis in myocardial infarction (TIMI) frame were counted.
ResultsA total of 34 patients with FFR>0.75 were enrolled with 61.8%(21 cases) of males and 38.2% (13 cases) of females. The mean age was (57.3±8.1) years old. High IMR accounted for 47.1% of all cases. There was significant difference between group H and N in TIMI frame (33.0 vs. 20.8, P=0.031). There were significant differences between group H1 and H2 in homocysteine (17.8 µmol/L vs. 12.0 µmol/L, P=0.005) and IMRcorr (58.0 vs. 36.1, P=0.002). IMRcorr was correlated to TIMI frame (r=0.40, P=0.012) for all cases. The sensitivity and specificity of inferring IMR≥35.3 by TIMI frame were 0.75 and 0.65 (P=0.049) with TIMI frame over 40.5.
ConclusionsHigh IMR may be one of the reasons for chest pain in patients with intermediate coronary stenosis. There is no correlation between vascular risk factors and IMR or CFR, while there is positive correlation between TIMI frame and IMR. The specificity is 65% for inferring IMR rise with TIMI frame over 40.5.
Key words:
Coronary disease; Microcirculation; Fractional flow reserve, myocardial; Coronary flow reserve; Index of microcirculatory resistance
Contributor Information
Dongfang He
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China
Meiyan Liu
Lijun Zhang
Chengjun Guo
Yunpeng Chi
Lin Zhao
Xiaojiang Zhang