Usefulness of the Fractional Flow Reserve Derived by Intracoronary Pressure Wire for Evaluating Angiographically Intermediate Lesions in Acute Coronary Syndrome

Introduction and objectives. In contrast to findings in stable ischemic heart disease, in acute coronary syndrome (ACS), measurement of the fractional flow reserve (FFR) using an intracoronary pressure wire has not been shown to be useful for evaluating angiographically equivocal coronary lesions. The aim of this study was to analyze outcomes at 1 year in ACS patients with lesions that were classed as intermediate on coronary angiography and which were not nonrevascularized because of the FFR value determined by intracoronary pressure wire. Methods. The observational study involved a cohort of patients admitted for ACS who had intermediate lesions on coronary angiography that were not revascularized because the FFR was >0.75. Functional studies were not carried out if there was angiographic evidence of instability. All-cause mortality, non-fatal myocardial infarction, revascularization of the target lesion and readmission for cardiac causes in the first year of the study were recorded. Results. The study included 106 patients with 127 lesions that were not revascularized because the FFR was >0.75. Their mean age was 69.9 +/- 10 years, 92 (86.8%) had non-ST-elevation ACS, the mean angiographic stenosis was 40.5 +/- 7.8%, and the mean FFR was 0.88 +/- 0.06. There were no complications during the procedure. The follow-up rate at 1 year was 95.1%. Events observed at 1 year were: 2 deaths (total mortality 1.9%), 0 fatal acute myocardial infarctions, 1 (0.9%) target lesion revascularization and 5 (4.7%) readmissions for cardiac causes. Conclusions. Once lesions with clear angiographic signs of instability are excluded, intracoronary pressure wire measurement could be useful in ACS patients for avoiding unnecessary revascularization of angiographically intermediate coronary lesions.