Meta-Analysis of Diagnostic Performance of Instantaneous Wave-Free Ratio versus Quantitative Flow Ratio for Detecting the Functional Significance of Coronary Stenosis

Abstract

Background. Fractional flow reserve (FFR), as a functional measurement of coronary stenosis, is recommended for guiding revascularization in intermediate coronary lesions. However, it still remains underutilized for potential reasons including time consumption, costs, or contraindications associated with adenosine administration. Here we performed this meta-analysis to assess the diagnostic performance of two adenosine-free indices, instantaneous wave free-ratio (iFR), and quantitative flow ratio (QFR) in evaluating coronary stenosis severity with FFR as the reference standard. Methods. PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched to include relevant studies with the diagnostic accuracy of iFR or QFR referenced to FFR. A bivariate model was applied to pool diagnostic parameters. We used Cochran’s Q test and I2 index to assess heterogeneity and identify the potential source of heterogeneity by meta-regression. Results. A total of 8213 lesions from 28 studies (19 for iFR and 9 for QFR) were included in this meta-analysis. The pooled sensitivity and specificity were 0.79 (95% CI, 0.75 to 0.83) and 0.85 (95% CI, 0.82 to 0.87) for iFR and 0.90 (95% CI, 0.84 to 0.93) and 0.88 (95% CI, 0.86 to 0.90) for QFR, respectively. Significantly higher sensitivity and specificity were observed in the bivariate analysis for QFR than for iFR (P < 0.001 for both). The area under summary receiver-operating curve of iFR and QFR was 0.89 (95% CI, 0.86 to 0.92) and 0.92 (95% CI, 0.89 to 0.94). Conclusion. Evidence suggests that both of the two indices have good performance in detecting functional ischemia of coronary arteries and QFR might be a promising method without requiring the pressure wire. Further application of QFR may potentially provide important information to clinicians in the assessment of coronary lesions.

Meta-Analysis of Diagnostic Performance of Contrast-Fractional Flow Reserve versus Quantitative Flow Ratio for Functional Assessment of Coronary Stenoses

“…ree previous meta-analyses assessed the diagnostic parameters of QFR for detecting significant coronary stenosis. e reliability of the analysis may have been affected by the lack of current studies and the inclusion of a conference abstract [7,11,12]. Another meta-analysis included 4 well-designed multicenter prospective studies, in which the QFR calculation followed a strict procedure and finished by well-trained operators, but the study sample was relatively small.…”

“…By reviewing the current meta-analysis of cFFR and QFR, we found that heterogeneity of the correlation values of cFFR (I 2 � 81.00%) [6] and sensitivity and specificity of QFR (I 2 ranged from 70.1% to 72.07% and 24.1% to 60.1%, resp.) [7,12] both are high. However, despite the large heterogeneity, we found that our research reported consistent results with previous studies, which reported that the sensitivity and specificity of cFFR were 88% and 93%, while the reported sensitivity of QFR ranged from 84% to 89%, with the specificity being 88% [6,7,12].…”

“…[7,12] both are high. However, despite the large heterogeneity, we found that our research reported consistent results with previous studies, which reported that the sensitivity and specificity of cFFR were 88% and 93%, while the reported sensitivity of QFR ranged from 84% to 89%, with the specificity being 88% [6,7,12]. At the same time, observational studies and a meta-analysis have shown that the diagnostic accuracy of cFFR and QFR was better than that of iFR, suggesting that both may have similar diagnostic accuracy.…”

“…e contrast-FFR (cFFR) and quantitative flow ratio (QFR) are two novel adenosine-free indices which show superior diagnostic accuracy to other adenosine-free options, including resting distal coronary pressure to aortic pressure ratio (Pd/Pa) and instantaneous wave-free ratio (iFR). It appears that either of these methods may serve as alternatives to FFR since both observational studies and meta-analyses show emerging evidence of cFFR and QFR as effective alternatives to FFR [4][5][6][7].…”

“…Recent meta-analyses reviewed major studies focusing on the diagnostic accuracy of cFFR or QFR using FFR as a reference [6,7,12]. However, there is still no systematic comparison between cFFR and QFR to evaluate their diagnostic performance.…”