Diagnostic performance of quantitative flow ratio in prospectively enrolled patients: An individual patient‐data meta‐analysis

Abstract

Objectives We aimed to provide robust performance estimates for quantitative flow ratio (QFR) in assessment of intermediary coronary lesions. Background Angiography‐based functional lesion assessment by QFR may appear as a cost saving and safe approach to expand the use of physiology‐guided percutaneous coronary interventions. QFR was proven feasible and showed good diagnostic performance in mid‐sized off‐line and on‐line studies with fractional flow reserve (FFR) as reference standard. Methods We performed a collaborative individual patient‐data meta‐analysis of all available prospective studies with paired assessment of QFR and FFR using the CE‐marked QFR application. The main outcome was agreement of QFR and FFR using a two‐step analysis strategy with a multilevel mixed model accounting for study and center level variation. Results Of 16 studies identified, four studies had prospective enrollment and provided patient level data reaching a total of 819 patients and 969 vessels with paired FFR and QFR: FAVOR Pilot (n = 73); WIFI II (n = 170); FAVOR II China (n = 304) and FAVOR II Europe‐Japan (n = 272). We found an overall agreement (mean difference 0.009 ± 0.068, I2 = 39.6) of QFR with FFR. The diagnostic performance was sensitivity 84% (95%CI: 77–90, I2 = 70.1), specificity 88% (95%CI: 84–91, I2 = 60.1); positive predictive value 80% (95%CI: 76–85, I2 = 33.4), and negative predictive value 95% (95%CI: 93–96, I2 = 75.9). Conclusions Diagnostic performance of QFR was good with FFR as reference in this meta‐analysis of high quality studies. QFR could provide an easy, safe, and cost‐effective solution for functional evaluation of coronary artery stenosis.

Comparison of quantitative flow ratio and fractional flow reserve with myocardial perfusion scintigraphy and cardiovascular magnetic resonance as reference standard. A Dan-NICAD substudy

“…Additionally, we showed that QFR may be useful for appropriate evaluation of visually estimated severe lesions not applicable for FFR measurement. The current findings add to the existing knowledge that QFR agrees with wire-based FFR in the majority of patients in head to head comparisons [5,6,11,16]. We found a low sensitivity of QFR and FFR when CMR and MPS were used as reference.…”

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.…”

“…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. It may be that the diagnostic performance of QFR in clinical practice is difficult to ascertain because it relies on clinical staff for accuracy and there are different protocols in each setting [12].…”

“…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].…”

“…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.…”