QFR Assessment and Prognosis After Nonculprit PCI in Patients With Acute Myocardial Infarction.

Background: Complete revascularization using either angiography-guided or fractional flow reserve (FFR)-guided strategy can improve clinical outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, there is concern that angiography-guided percutaneous coronary intervention (PCI) may result in un-necessary PCI of the non-infarct-related artery (non-IRA), and its long-term prognosis is still unclear.

Objectives: This study sought to evaluate clinical outcomes after non-IRA PCI according to the quantitative flow ratio (QFR).

Methods: We performed post hoc QFR analysis of non-IRA lesions of AMI patients enrolled in the FRAME-AMI (FFR Versus Angiography-Guided Strategy for Management of AMI With Multivessel Disease) trial, which randomly allocated 562 patients into either FFR-guided PCI (FFR ≤0.80) or angiography-guided PCI (diameter stenosis >50%) for non-IRA lesions. Patients were classified by non-IRA QFR values into the QFR ≤0.80 and QFR >0.80 groups. The primary outcome was a major adverse cardiac event (MACE), a composite of cardiac death, myocardial infarction, and repeat revascularization.

Results: A total of 443 patients (552 lesions) were eligible for QFR analysis. Of 209 patients in the angiography-guided PCI group, 30.0% (n = 60) underwent non-IRA PCI despite having QFR >0.80 in the non-IRA. Conversely, only 2.7% (n = 4) among 209 patients in the FFR-guided PCI group had QFR >0.80 in the non-IRA. At a median follow-up of 3.5 years, the rate of MACEs was significantly higher among patients with non-IRA PCI despite QFR >0.80 than in patients with deferred PCI for non-IRA lesions (12.9% vs 3.1%; HR: 4.13; 95% CI: 1.10-15.57; P = 0.036). Non-IRA PCI despite QFR >0.80 was associated with a higher risk of non-IRA MACEs than patients with deferred PCI for non-IRA lesions (12.9% vs 2.1%; HR: 5.44; 95% CI: 1.13-26.19; P = 0.035).

Conclusions: In AMI patients with multivessel disease, 30.0% of angiography-guided PCI resulted in un-necessary PCI for the non-IRA with QFR >0.80, which was significantly associated with an increased risk of MACEs than in those with deferred PCI for non-IRA lesions. (FFR Versus Angiography-Guided Strategy for Management of AMI With Multivessel Disease [FRAME-AMI] ClinicalTrials.gov number; NCT02715518).