Prognostic Value of Endogenous-Type Coronary Microvascular Dysfunction After Elective Percutaneous Coronary Intervention.

Background: Global coronary flow reserve (G-CFR) impairment represents coronary microvascular dysfunction (CMD) and correlates with poor prognosis. Hyperemic coronary flow is reduced in conventional CMD, but normal or mildly reduced with elevated resting flow in endogenous-type CMD (E-CMD). This retrospective study assessed the prognostic value of post-percutaneous coronary intervention (PCI) CMD, focusing on E-CMD.

Methods and results: We included 320 chronic coronary syndrome (CCS) patients undergoing PCI and post-PCI phase contrast cine-cardiac magnetic resonance imaging (CMR). Major adverse cardiac and cerebrovascular events (MACCE) were evaluated, considering the presence of post-PCI CMD and E-CMD based on G-CFR and resting myocardial flow assessed by coronary sinus flow using CMR. CMD was defined as G-CFR <2.0 and classified as E-CMD or non-E-CMD. Post-PCI CMD was observed in 43.4% of patients, 63.3% exhibiting E-CMD. During a median 2.5-year follow-up, MACCE occurred in 26 (8.1%) patients, more often in those with CMD (11.5% vs. 5.5%; P=0.063). MACCE incidence was higher in E-CMD than non-E-CMD and non-CMD (14.8% vs. 5.9% and 5.5%, respectively; P=0.027). Kaplan-Meier analysis revealed worse prognosis in E-CMD (P=0.025). Cox proportional hazards modeling revealed that E-CMD independently predicted MACCE (hazard ratio 3.24; 95% confidence interval 1.47-7.14; P=0.004).

Conclusions: Post-PCI CMD, particularly E-CMD, was significantly associated with worse outcomes in CCS patients. Post-PCI CMD evaluation could guide therapeutic strategies for CCS patients.