Natural History of Coronary Atherosclerosis in Patients With Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement: The Role of Quantitative Flow Ratio

Background: The prognostic impact of functionally significant coronary artery disease, as assessed with quantitative flow ratio (QFR), in patients with severe aortic stenosis treated with transcatheter aortic valve replacement is unknown. Methods: This is a retrospective study with blind analysis of angiographic data, enrolling consecutive patients with severe aortic stenosis treated with transcatheter aortic valve replacement at 4 Italian centers. None of the patients enrolled received pre-transcatheter aortic valve replacement or concomitant coronary revascularization, either for the absence of significant coronary stenoses or by clinical decision. Visual estimation of diameter stenosis and QFR analysis were performed in all coronary arteries. The end point was all-cause mortality at a 3-year follow-up. Results: A total of 318 patients were enrolled. At visual estimation, 140 patients (44%) presented a diameter stenosis ≥50% in at least 1 coronary artery, whereas 78 patients (24.5%) had at least 1 vessel with QFR <0.80 and, therefore, included in the positive QFR group. Overall, 69 (21.7%) patients died during the follow-up. In the Kaplan-Meier analysis, patients with positive QFR experienced significantly higher rates of death during follow-up compared with those without (51.1% versus 12.1%; P<0.001), whereas no significant difference was evident in terms of death between patients with or without significant coronary artery disease according to angiographic evaluation (24.3% versus 19.7%; P=0.244). In a multivariate regression model, positive QFR was an independent predictor of all-cause death during follow-up (hazard ratio, 5.31 [95% CI, 3.21-8.76]). Conclusions: Coronary QFR can predict mortality in patients with severe aortic stenosis treated with transcatheter aortic valve replacement without revascularization.