Clinical Events After Deferral of LAD Revascularization Following Physiological Coronary Assessment

Abstract

BackgroundPhysicians are not always comfortable deferring treatment of a stenosis in the left anterior descending (LAD) artery because of the perception that there is a high risk of major adverse cardiac events (MACE). The authors describe, using the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) trial, MACE rates when LAD lesions are deferred, guided by physiological assessment using fractional flow reserve (FFR) or the instantaneous wave-free ratio (iFR).ObjectivesThe purpose of this study was to establish the safety of deferring treatment in the LAD using FFR or iFR within the DEFINE-FLAIR trial.MethodsMACE rates at 1 year were compared between groups (iFR and FFR) in patients whose physiological assessment led to LAD lesions being deferred. MACE was defined as a composite of cardiovascular death, myocardial infarction (MI), and unplanned revascularization at 1 year. Patients, and staff performing follow-up, were blinded to whether the decision was made with FFR or iFR. Outcomes were adjusted for age and sex.ResultsA total of 872 patients had lesions deferred in the LAD (421 guided by FFR, 451 guided by iFR). The event rate with iFR was significantly lower than with FFR (2.44% vs. 5.26%; adjusted HR: 0.46; 95% confidence interval [CI]: 0.22 to 0.95; p = 0.04). This was driven by significantly lower unplanned revascularization with iFR and numerically lower MI (unplanned revascularization: 2.22% iFR vs. 4.99% FFR; adjusted HR: 0.44; 95% CI: 0.21 to 0.93; p = 0.03; MI: 0.44% iFR vs. 2.14% FFR; adjusted HR: 0.23; 95% CI: 0.05 to 1.07; p = 0.06).ConclusionsiFR-guided deferral appears to be safe for patients with LAD lesions. Patients in whom iFR-guided deferral was performed had statistically significantly lower event rates than those with FFR-guided deferral.

Outcomes of Deferred Revascularization Following Physiological Coronary Assessment Using Fractional Flow Reserve

“…A study by Sen et al showed that in LAD lesions, iFR-guided deferral is safer than FFR-guided deferral and significantly lower MACE rates. 15 However, our study was only with FFR, not in comparison with other functional modalities of assessment.…”

Clinical Outcome of Lesions With Discordant Results Among Different Invasive Physiologic Indices ― Resting Distal Coronary to Aortic Pressure Ratio, Resting Full-Cycle Ratio, Diastolic Pressure Ratio, Instantaneous Wave-Free Ratio, and Fractional Flow Reserve ―

“…Recently, post-hoc analysis of the pooled population of the DEFINE-FLAIR and iFR-SWEDEHEART trials 25 and post-hoc analysis of the DEFINE-FLAIR trial 26 suggested the possible superiority of iFR-guidance in deferral of LAD lesions or patients with acute coronary syndrome, based on higher risk of MACE after FFRguidance in these patient subsets. However, none of those post-hoc analyses had enough study power to validate the differences among subgroups.…”

Per-Vessel Level Analysis of Fractional Flow Reserve and Instantaneous Wave-Free Ratio Discordance ― Insights From the AJIP Registry ―

“…8 The insights from this study suggest one explanation of the results of the DEFINE-FLAIR LAD sub-analysis, which demonstrated superior clinical outcomes among patients deferred with iFR in the LAD compared to FFR. 9 The rate the composite of cardiovascular death, myocar-logically diffuse and 81.5% (123/151) physiologically focal.…”