ABSTRACT Background Coronary microvascular dysfunction (CMD) can be phenotyped as endogenous or classical. Aims This study investigated the prognostic significance of these CMD endotypes in patients with chronic coronary syndrome after elective percutaneous coronary intervention (PCI). Methods This retrospective study included 205 patients who underwent elective PCI in the left anterior descending artery (LAD). Post‐PCI, coronary flow was assessed using stress transthoracic Doppler echocardiography to measure diastolic peak flow velocity (DPV) and calculate coronary flow velocity reserve (CFVR). CMD was defined as CFVR ≤ 2.0 and further classified as endogenous (resting DPV > 33 cm/s) or classical (resting DPV ≤ 33 cm/s). This cutoff was determined by the 34.6th percentile of sorted DPV values, corresponding to reduced CFVR distribution. The primary endpoint was major adverse cardiac events (MACE), a composite of cardiac death, myocardial infarction, heart failure hospitalization, and target vessel revascularization. Results Over a median follow‐up of 2.3 years, 30 patients (14.6%) experienced MACE. The cumulative incidence of MACE was significantly higher in patients with endogenous‐type CMD compared to those with classical‐type CMD or without CMD ( p < 0.001). In multivariate Cox proportional hazard analysis, endogenous‐type CMD remained an independent predictor of MACE (hazard ratio: 3.28; 95% confidence interval: 1.53–7.04; p = 0.002). Conclusions Endogenous‐type CMD in the LAD territory following elective PCI is an independent predictor of MACE. Noninvasive phenotyping of CMD post‐PCI using stress echocardiography may improve risk stratification and guide personalized management strategies for these high‐risk patients.
Watanabe et al. (Tue,) studied this question.