Prognostic value of global coronary flow reserve before and after elective percutaneous coronary intervention in patients with chronic coronary syndrome.

Background: Impaired global coronary flow reserve (G-CFR), evaluated through phase-contrast cine cardiovascular magnetic resonance (PC-CMR), has been linked to worse outcomes in patients with cardiovascular disease. This study aimed to investigate the prognostic value of G-CFR improvement, as evaluated using PC-CMR imaging pre- and post-percutaneous coronary intervention (PCI).

Methods: In this single-center study, 320 patients with chronic coronary syndrome (CCS) who underwent pre- and post-PCI PC-CMR measurements were followed up to determine major adverse cardiac or cerebrovascular events (MACCE) predictors. MACCE was defined as a composite of cardiac death, nonfatal myocardial infarction, hospitalization due to heart failure, or ischemic stroke. The association between CMR parameters, including baseline data, G-CFR changes post-PCI, and MACCE, was investigated.

Results: G-CFR improvement was observed in 51.6% (165/320) patients, while MACCE occurred in 8.1% (26/320) during a median follow-up period of 2.5 years. G-CFR improvement was significantly associated with a lower pre-PCI G-CFR. The log-rank test revealed a significant association between patients without G-CFR improvement post-PCI and a poor prognosis. Patients with lower pre-PCI G-CFR and lack of G-CFR improvement exhibited the highest incidence of MACCE. The multivariable Cox proportional hazard model revealed that lack of G-CFR improvement was an independently significant MACCE predictor from pre-PCI G-CFR and SYNTAX (Synergy between PCI with Taxus and Cardiac Surgery) score.

Conclusion: Besides the association between pre- and post-PCI lower G-CFR and worse prognosis, the presence or absence of G-CFR improvement post-PCI may provide novel insights into the prognosis following elective PCI in patients with CCS.