Abstract
BACKGROUND: The association between the quantitative flow ratio (QFR) and adverse events after drug-coated balloon (DCB) angioplasty for in-stent restenosis (ISR) lesions has not been investigated. HYPOTHESIS: Post-procedural QFR is related to adverse events in patients undergoing DCB angioplasty for ISR lesions. METHODS: This retrospective study included data from patients undergoing DCB angioplasty for drug-eluting stent (DES) ISR between January 2016 and February 2019. The QFR was measured at baseline and after DCB angioplasty. The endpoint was the vessel-oriented composite endpoint (VOCE), defined as a composite of cardiac death, vessel-related myocardial infarction, and ischemia-driven target vessel revascularization. RESULTS: Overall, 177 patients with 185 DES-ISR lesions were included. During 1-year follow-up, 27 VOCEs occurred in 26 patients. The area under curve (AUC) of the post-procedural QFR was statistically greater than that of the in-stent percent diameter stenosis (0.77, 95% confidence interval [CI] 0.67-0.87 vs. 0.64, 95% CI 0.53-0.75; p = .032). Final QFR cutoff of 0.94 has the best predictive accuracy for VOCE. A QFR > 0.94 was associated with a lower risk of VOCE compared to a QFR ≤ 0.94 (log-rank test, p < .0001). Survival analysis using the multivariable Cox model showed that a post-procedural QFR ≤ 0.94 was an independent predictor of 1-year VOCE (hazard ratio 6.53, 95% CI 2.70-15.8, p < .001). CONCLUSIONS: A lower QFR value was associated with worse clinical outcomes at 1 year after DCB angioplasty for DES-ISR.