P3660Clinical usefulness of instantaneous wave-free ratio for evaluation of coronary artery lesion with prior myocardial infarction

Abstract

Background: Fractional flow reserve (FFR) is useful for functional evaluation of coronary artery stenosis, even in lesions with prior myocardial infarction (pMI). Instantaneous wave-free ratio (iFR) is a vasodilator-free alternative and shows good diagnostic classification match with FFR. In addition, recent study demonstrated that iFR-guided revascularization strategy was non-inferior to FFR-guided revascularization strategy. Purpose:We investigated the clinical usefulness of iFR in coronary artery lesions with pMI. Methods: Consecutive 200 patients with stable coronary artery disease who were admitted to 4 hospitals in Japan between May 2014 and July 2016 were retrospectively analyzed. Patients were divided into 2 subgroups according to the presence or absence of pMI. We evaluated clinical application of iFR-guided revascularization strategy with respect to the rate of major adverse cardiac events (MACE). MACE was defined as all-cause death, non-fatal MI, unstable angina pectoris requiring revascularization, fatal arrhythmia and heart failure requiring hospitalization. Results: A total of 200 coronary artery lesions were evaluated including 44 pMI territories lesions (73.7±8.2 years old, male gender 77.3%) and 156 de novo coronary artery lesions (72.8±9.6 years old, male gender 72.4%). The prevalence of diabetes mellitus, dyslipidemia and prior percutaneous coronary artery intervention was significantly higher in patients with pMI than those without pMI. iFR was closely correlated with FFR in lesions with pMI and without pMI (r=0.81 and 0.72; P<0.001, respectively). In lesions with pMI, iFR cut-off 0.89 was optimal against the clinical FFR cut-off 0.80 according to the receiver operating characteristics curve analysis with a sensitivity of 78% and specificity 100% (area under the receiver operating characteristics curve 0.92), while in lesions without pMI, iFR cut-off value against the clinical FFR cut-off value of 0.80 was 0.92. There was no statistical significant difference in iFR cut off value against FFR value of 0.80 between the lesion with and without pMI (P=0.42). PCI was deferred in 72.7% patients with pMI and 73.1% patients without pMI. Among them, MACE occurred 3.0% in patients with pMI and 5.3% in those without pMI during 12 months follow-up without statistical significance (hazard ratio 1.73, 95% confidence interval 0.10-3.21, P=0.58). (See figure) (Figure presented) Conclusion: iFR may be useful for clinical decision-making and for prediction of prognosis even in patients with pMI.