Clinical Significance of Coronary Flow Reserve Improvement After Elective Percutaneous Coronary Intervention

Limited research has explored the prognostic significance of changes in coronary flow velocity reserve (CFVR), as measured by stress-transthoracic Doppler echocardiography (S-TDE), following elective percutaneous coronary intervention (PCI). This study aimed to assess whether post-PCI changes in CFVR are associated with major adverse cardiac events (MACE) and to identify baseline clinical factors that predict improvement of CFVR.

A retrospective analysis was performed on 184 patients who underwent elective FFR-guided PCI for the left anterior descending (LAD) artery. Standard pre-PCI TDE examinations and pre- and post-PCI physiological assessments using S-TDE were performed. Patients were categorized based on CFVR improvement, defined as an increase greater than the median value of CFVR changes. MACE, including all-cause death, myocardial infarction, ischemic stroke, and heart failure requiring hospitalization, was evaluated.

The median improvement in CFVR was 0.50 (28.8%). During a median follow-up period of 1.9 years, MACE occurred in 26 patients (14.1%). Patients without CFVR improvement had significantly worse outcomes (p = 0.029). In multivariate Cox regression analysis, both lower pre-PCI CFVR and lack of CFVR improvement were associated with poor prognosis. A multivariate logistic regression analysis identified absence of diabetes, lower pre-PCI FFR, lower pre-PCI CFVR, and longer pre-PCI deceleration time of diastolic coronary flow as predictors of CFVR increase, with an AUC of 0.814 (95% CI: 0.755-0.873).

In patients undergoing elective FFR-guided LAD PCI, a lower pre-PCI CFVR and lack of CFVR improvement were associated with poor prognosis, whereas a comprehensive pre-PCI evaluation predicted CFVR improvement.