Vessel‐Oriented Analysis on the Relationship Between Quantitative‐Flow Ratio and Mortality in Patients With Severe Aortic Stenosis and Intermediate Coronary Lesions

Background Quantitative flow ratio (QFR) is effective in predicting mortality in patients undergoing transcatheter aortic valve replacement (TAVR). How QFR reclassifies coronary artery disease (CAD) at vessel‐level compared to angiography and how this influences the risk of death, remains undetermined. Methods We calculated QFR from consecutive 280 TAVR patients with bystander coronary stenoses. All lesions were managed conservatively. Angiographic CAD was defined by a diameter stenosis ≥ 50%, functional CAD by a QFR ≤ 0.80. The outcome was mortality at 3 years. Results Overall, 635 lesions were included. Angiographic CAD was evident in 165 (26.0%), functional CAD in 17 (11.2%) (reclassification: p < 0.001). Angiography/QFR mismatch occurred in 22.5%, mostly in large vessels and lesions located in the proximal left anterior descending (LAD). QFR ≤ 0.80 was an independent predictor of death (HR 2.91, 95% CI 1.94−4.36; p < 0.001). The risk was progressively increased for lower QFR values and positive QFR at LAD site (vs. QFR > 0.80 HR: 3.92, 95% CI 2.78−5.53; p < 0.001; vs. QFR ≤ 0.80 at non‐LAD site: HR 2.65, 95% CI 1.07−6.59; p = 0.034). Conclusions QFR leads to a significant reclassification of CAD rates at vessel‐level and shows a significant prognostic value in patients undergoing TAVR.