Impact of quantitative flow ratio on outcomes after percutaneous coronary intervention for chronic total occlusion.

The clinical implication of a post-percutaneous coronary intervention (PCI) quantitative flow ratio (QFR) in coronary artery disease (CAD) patients with chronic total occlusion (CTO) remains insufficiently explored. This single-center retrospective observational study analyzed 195 CTO lesions from 195 CAD patients who underwent successful PCI with drug-eluting stent implantation and were assessed for post-PCI QFR. The primary end point was target lesion revascularization (TLR) at 3 years. The receiver-operating characteristic curve was used to calculate the optimal cutoff value of post-PCI QFR for predicting 3-year TLR. Patients were stratified on the basis of the optimal cutoff value, and the predictors for 3-year TLR were assessed by multivariate Cox proportional hazard models. The ROC curve demonstrated that the cutoff value of post-PCI QFR for predicting 3-year TLR was 0.84, with a sensitivity of 61% and specificity of 66%. The cumulative incidence of TLR at 3 years was significantly higher in the low post-PCI QFR group (≤ 0.84) compared to the high post-PCI QFR group (> 0.84) (22.0% versus 8.4%, P = 0.017). In multivariate analysis, age (hazard ratio [HR], 0.94 [0.91 to 0.98]), renal failure on dialysis (HR, 3.89 [1.58 to 9.55]), ostial lesion (HR, 5.01 [1.90 to 13.23]), and post-PCI QFR ≤ 0.84 (HR, 2.49 [1.04 to 5.97]) were independent predictors for 3-year TLR. Lower post-PCI QFR was associated with increased 3-year TLR in CAD patients with CTO.