Background: Measurement of fractional flow reserve (FFR) is useful tool for assessing the functional severity of coronary artery stenosis and for clinical decision of treatment strategy. Many studies have shown that FFR measurement <0.75 is specific for ischemia, but there is a controversy about whether we need to intervene the lesion of FFR measurement 0.75-0.80 or not. The objective of this study is to compare the clinical outcomes of revascularization versus conservative treatment in the borderline FFR measurement lesions.
Methods: We used the FFR-Registry database out of 4 centers in Korea. In 267 patients (mean age 62 ± 10 years, male 69%), 277 lesions (LAD, 213; LCX, 40; RCA, 24) with FFR measurement between 0.75 and 0.80 (mean 0.77±0.02) were included in this study. The rate of major adverse cardiac events (MACE; death, myocardial infarction, target lesion revascularization) and target lesion related events (TLRE; FFR-evaluated lesion revascularization, FFR-evaluated lesion-related myocardial infarction) were evaluated at 1 year follow up. Sixty-seven lesions from 66 patients were deferred from revascularization (Conservative group) and 210 lesions from 201 patients were treated with percutaneous coronary intervention (PCI group).
Results: For 1 year follow-up, 4 cases of TLRE (4 cases of FFR-evaluated lesion revascularization and no case of FFR-evaluated lesion-related myocardial infarction) from 4 patients occurred in the Conservative group and 8 cases of TLRE (8 cases of FFR-evaluated lesion revascularization and 1 case of FFR-evaluated lesion-related myocardial infarction) from 8 patients occurred in the PCI group.
Five cases of MACE (1 case of death, no case of myocardial infarction and 5 cases of target lesion revascularization) occurred in the Conservative group and 13 cases of MACE (4 cases of death, 2 cases of myocardial infarction and 9 cases of target lesion revascularization) occurred in the PCI group.
Using Cox proportional hazard model, there was no difference in lesion-related events between Conservative-group and PCI-group (hazard ratio 0.303, 95% CI 0.5-2.025, P = 0.218).
Conclusions: In coronary lesions with borderline FFR, revascularization did not show the better clinical outcome compared to medical treatment. Therefore, lesions with borderline FFR measurement can be deferred from revascularization without an increased risk for lesion-related outcomes.
