Fractional flow reserve versus angiography for revascularization in patients with coronary artery disease: A systematic review and meta-analysis of randomized controlled trials

Background: Fractional flow reserve (FFR) is routinely used to assess the ischemic potential of a coronary artery lesion. However, recently published randomized control trials have questioned the advantage of FFR over angiography to guide revascularization. Whether FFR guided revascularization provides clinical benefit over angiography remains unclear. Methods: We performed a meta-analysis in patients with stable coronary artery disease (CAD), acute coronary syndrome (ACS), multivessel or single vessel CAD undergoing revascularization comparing FFR versus angiography to guide revascularization. Randomized control trials comparing FFR angiography guided revascularization were searched through PubMed, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central, Scopus, Google Scholar, and Web of Science databases. The primary endpoints included cardiovascular mortality, repeat revascularization, myocardial infarction, major adverse cardiac events, stroke or transient ischemic attack and target lesion revascularization. We also evaluated the procedural outcomes including the average number of stents used between the two groups, procedure time and contrast volume used. Event rates were compared using a forest plot of odds ratios using a random-effects model assuming interstudy heterogeneity. Results: The meta-analysis included 13 trials in which 7415 patients met the eligibility criteria. There was no significant difference between the FFR versus angiography guided revascularization groups across all clinical measures including all-cause mortality (OR = 1.06, 95% CI = 0.74-1.53, P = 0.74, I2= 27%), cardiovascular mortality (OR = 0.81, 95% CI = 0.43-1.52, P = 0.51, I2= 44%), repeat revascularization (OR = 1.02, 95% CI = 0.83-1.26, P = 0.83, I2= 17%), myocardial infarction (OR = 0.92, 95% CI = 0.69-1.21, P = 0.54, I2= 36%), major adverse cardiac event (OR = 0.82, 95% CI = 0.62-1.08, P = 0.15, I2= 41%), stroke or transient ischemic attack (OR = 1.49, 95% CI = 0.87-2.55, P = 0.15, I2= 0%) and target lesion revascularization (OR = 0.86, 95% CI = 0.44-1.69, P = 0.67, I2= 0%). A sensitivity analysis was performed for studies that included patients exclusively with an ACS and studies that used FFR coronary artery bypass grafting as a revascularization strategy. There was no difference in any of the clinical outcomes between the two groups in the sensitivity analysis. In terms of procedural outcomes, the average number of stents used was lower in the FFR group as compared to the angiography group, mean difference (MD) of -0.79 (95% CI = - 1.10, - 0.48), P < 0.00001) with no difference in procedure time or contrast volume used. Conclusion: This meta-analysis suggests that FFR when used in conjunction with angiography prevents unnecessary PCI without any difference in clinical outcomes between the two groups.