Clinical Implication of Quantitative Flow Ratio After Percutaneous Coronary Intervention for 3-Vessel Disease
N Kogame, K Takahashi, M Tomaniak et al.

KEYWORDS
DES; PCI; quantitative flow ratio

OBJECTIVES- The aim of this study was to investigate the impact of post–percutaneous coronary intervention (PCI) quantitative flow ratio (QFR) on clinical outcomes in patients with de novo 3-vessel disease (3VD) treated with contemporary PCI.

BACKGROUND- The clinical impact of post-PCI QFR in patients treated with state-of-art PCI for de novo 3VD is undetermined.

METHODS - All vessels treated in the SYNTAX (SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery) II trial were retrospectively screened and analyzed for post-PCI QFR. The primary endpoint of this substudy was vessel-oriented composite endpoint (VOCE) at 2 years, defined as the composite of vessel-related cardiac death, vessel-related myocardial infarction, and target vessel revascularization. The receiver-operating characteristic curve was used to calculate the optimal cutoff value of post-PCI QFR for predicting 2-year VOCE. All the analyzable vessels were stratified on the basis of the optimal cutoff value.

RESULTS- A total of 968 vessels treated with PCI were screened. Post-PCI QFR was analyzable in 771 (79.6%) vessels. A total of 52 (6.7%) VOCEs occurred at 2 years. The mean value of post-PCI QFR was 0.91 ± 0.07. The diagnostic performance of post-PCI QFR to predict 2-year VOCE was moderate (area under the curve: 0.702; 95% confidence interval: 0.633 to 0.772), with the optimal cutoff value of post-PCI QFR for predicting 2-year VOCE 0.91 (sensitivity 0.652, specificity 0.635). The incidence of 2-year VOCE in the vessels with post-PCI QFR <0.91 (n = 284) was significantly higher compared with vessels with post-PCI QFR ≥0.91 (n = 487) (12.0% vs. 3.7%; hazard ratio: 3.37; 95% confidence interval: 1.91 to 5.97; p < 0.001).

CONCLUSIONS- A higher post-PCI QFR value is associated with improved vessel-related clinical outcomes in state-of-the art PCI practice for de novo 3VD. Achieving a post-PCI QFR value ≥0.91 in all treated vessels should be a target when treating de novo 3VD. These findings require confirmation in future prospective trials.