Prognostic Significance of Endogenous-Type Coronary Microvascular Dysfunction in the Left Anterior Descending Artery After Elective Percutaneous Coronary Intervention.

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.