Diagnostic performance of instantaneous wave-free ratio for the evaluation of coronary stenosis severity confirmed by fractional flow reserve: A PRISMA-compliant meta-analysis of randomized studies

BACKGROUND: The instantaneous wave-free ratio (iFR) is a new vasodilator-free index of coronary stenosis severity. The aim of this meta-analysis is to assess the diagnostic performance of iFR for the evaluation of coronary stenosis severity with fractional flow reserve as standard reference. METHODS: We searched PubMed, EMBASE, CENTRAL, ProQuest, Web of Science, and International Clinical Trials Registry Platform (ICTRP) for publications concerning the diagnostic value of iFR. We used a random-effects covariate to synthesize the available data of sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR−), and diagnostic odds ratio (DOR). Overall test performance was summarized by the summary receiver operating characteristic curve (sROC) and the area under the curve (AUC). RESULTS: Eight studies with 1611 subjects were included in the meta-analysis. The pooled sensitivity, specificity, LR+, LR−, and DOR for iFR were respectively 73.3% (70.1–76.2%), 86.4% (84.3–88.3%), 5.71 (4.43–7.37), 0.29 (0.22–0.38), and 20.54 (16.11–26.20). The area under the summary receiver operating characteristic curves for iFR was 0.8786. No publication bias was identified. CONCLUSION: The available evidence suggests that iFR may be a new, simple, and promising technology for coronary stenosis physiological assessment.