Background. There is little information available regarding deferral of revascularization in cases of fractional flow reserve (FFR) measurements in the borderline range (between 0.75 to 0.80). The objectives of this study were to evaluate the clinical outcomes of patients with moderate coronary lesions and FFR measurements between 0.75 and 0.80, comparing those who underwent coronary revascularization (CR) to those who had medical treatment (MT), and to determine the predictive factors of major adverse cardiac events (MACE) at follow-up. Methods. A total of 107 consecutive patients (mean age 62 ± 10 years) with at least one moderate coronary lesion (mean percent diameter stenosis 47 ± 12%) evaluated by coronary pressure wire with FFR measurement between 0.75 and 0.80 (mean 0.77 ± 0.02) were included in the study. Maximal hyperemia was obtained by intracoronary administration of adenosine (mean dose 215 ± 84 μg). MACE (coronary revascularization, myocardial infarction, cardiac death) and the presence of angina were evaluated at follow-up. Results. A total of 63 patients (59%) underwent CR and 44 patients (41%) had MT, with no clinical differences between groups. At a mean follow-up of 13 ± 7 months, MACE related to the coronary lesion evaluated by FFR were higher in the MT group compared to CR group (23% vs 5%, difference 18%, 95% CI 5%–30%, p=0.005). FFR measurement in an artery supplying a territory with previous myocardial infarction was the only predictive factor of MACE in the MT group (odds ratio 14.1, 95% CI 1.3–39, p=0.03). The presence of angina at follow-up was more frequent in the MT group compared to the CR group (41% vs 9%, difference 32%, 95% CI 11%–49%, p<0.001). Conclusions. In patients with moderate coronary lesions and FFR measurements in the “grey zone” range deferral of revascularization was associated with a higher rate of cardiac events and a higher prevalence of angina at follow-up, especially in those with previous myocardial infarction in the territory evaluated by FFR. These results suggest that a FFR cut-off point of 0.80 rather than 0.75 might be more appropriate for deferring coronary revascularization in these cases.
Read full abstract