Diagnostic performance of resting full-cycle ratio in identifying coronary lesions causing myocardial ischaemia: a meta-analysis

Abstract

Background The resting full-cycle ratio (RFR), a new non-congestive resting index, is commonly used for physiological evaluations of coronary arteries. Aims This study aims to evaluate the accuracy of RFR in detecting coronary artery stenosis with hemodynamic significance using fractional flow reserve (FFR) as the reference standard. Methods Using ‘RFR, resting full-cycle ratio’ as the search term, we searched PubMed, Embase, Cochrane Library, and Web of Science databases, screening the literature according to the inclusion and exclusion criteria. By applying FFR ≤ 0.80 and RFR ≤ 0.89 as the diagnostic criteria for ischaemia, we analysed the synthetic sensitivity, specificity, and corresponding 95% confidence intervals, then synthesised the summary receiver operating characteristic curve (SROC). Results Three studies were included in this meta-analysis, comprising 1,084 patients with 1,312 lesions. When we used FFR ≤ 0.80 as the reference standard, the synthesised sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), and negative likelihood ratio (LR-) of RFR in the diagnosis of coronary ischaemia were 73%, 81%, 67%, 85%, 3.95, and 0.33, respectively. Besides, the area under the curve (AUC) was 0.8276. Conclusion Using FFR as the reference standard, RFR has good diagnostic accuracy in detecting coronary ischaemic lesions and may be an effective alternative to FFR in the future, to some extent.