Validation of Quantitative Flow Ratio Derived Virtual Angioplasty With Post–angioplasty Fractional Flow Reserve. The Qimera–i Study

Abstract Backgroud Quantitative flow ratio (QFR) virtual angioplasty with pre–PCI residual QFR showed better results compared with angiographic approach to assess post–PCI functional results. However correlation with pre–PCI residual QFR and post–PCI fractional flow reserve (FFR) is lacking. Methods Multicenter prospective study including consecutive patientswith angiographically 50–90% coronary lesions and positive QFR result. All patients were evaluated with QFR, hyperemic and non–hyperemic pressure ratios (NHPR) before and after the index PCI. Pre–PCI residual QFR (virtual angioplasty) was calculated and compared with post–PCI fractional flow reserve (FFR), QFR and NHPR. Results A total of 84 patients with 92 treated coronary lesions were included, with a mean age of 65.5±10.9 years and 59% of single vessel lesion being the left anterior descending artery in 69%. The mean vessel diameter was 2.82±0.41 mm. Procedural success was achieved in all cases, with a mean number of implanted stents of 1.17±0.46. Baseline QFR value was 0.69 ± 0.12 and baseline FFR and NHPR were 0.73 + 0.08 and 0.82 + 0.11, respectively. Mean post–PCI FFR increased to 0.87 ±0.05 whereas residual QFR had been estimated as 0.95 ± 0.05 showing poor correlation with post–PCI FFR (0.163; 95%CI:0.078–0.386) and a low diagnostic accuracy (30.9%, 95%CI:20–43%). Conclusions In this analysis, the results of QFR–based virtual angioplasty did not seem to accurately correlate with post–PCI FFR.