Prevalence and characteristics of coronary microvascular dysfunction in post-percutaneous coronary intervention patients with recurrent chest pain

Background: Coronary microvascular dysfunction (CMD) and obstructive coronary artery disease (CAD) are likely to exist side-by-side, thereby probably inducing angina pectoris symptoms of some patients not effectively relieved after revascularization. We aimed to evaluate the prevalence and characteristics exhibited by CMD in patients with recurrent chest pain who received percutaneous coronary intervention (PCI) before. Methods: We conducted a single-center cross-sectional retrospective study. A total of 373 patients having received PCI were hospitalized for recurrent chest pain. Subsequently, they underwent coronary angiography and a rest/stress dynamic and routine gated myocardial perfusion imaging (MPI). At the vascular level, if any coronary artery stenosis <50% and myocardial flow reserve (MFR) <2.0 in the corresponding territory was considered to result from CMD. At the participant level, the CMD group was defined as one of the non obstructive coronary arteries, in accordance with CMD at the vascular level. Results: A total of 102 patients were finally recruited. At the vascular level, 274 vessels were eligible for inclusion, and the proportion of CMD was 43.1% (118/274). At the participant level, 49.0% (50/102) postPCI patients with recurrent chest pain were indicated as CAD coexisting with CMD. Body mass index (BMI), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) in CMD patients exceeded those in controls. The stress myocardial blood flow (MBF) of CMD patients was significantly decreased than controls (stress MBF of left ventricle in CMD vs. control: 1.36 +/- 0.43 vs. 2.50 +/- 0.70, P<0.01). After age adjustment, multivariate logistic regression analysis revealed that increased BMI (OR: 1.405, 95% CI: 1.048-1.882) and LDL-C (OR: 3.094, 95% CI: 1.044-9.173) showed independent correlations with CMD (P<0.05). Conclusions: The prevalence of CMD could be relatively high in post-PCI patients suffering from recurrent angina with no need for revascularization, and increased BMI and LDL-C could be independent predictors of CMD.