Clinical Outcomes in High‐Gradient, Classical Low‐Flow, Low‐Gradient, and Paradoxical Low‐Flow, Low‐Gradient Aortic Stenosis After Transcatheter Aortic Valve Implantation: A Report From the SwissTAVI Registry

BACKGROUND: In view of the rising global burden of severe symptomatic aortic stenosis, its early recognition and treatment is key. Although patients with classical low‐flow, low‐gradient (C‐LFLG) aortic stenosis have higher rates of death after transcatheter aortic valve implantation (TAVI) when compared with patients with high‐gradient (HG) aortic stenosis, there is conflicting evidence on the death rate in patients with severe paradoxical low‐flow, low‐gradient (P‐LFLG) aortic stenosis. Therefore, we aimed to compare outcomes in real‐world patients with severe HG, C‐LFLG, and P‐LFLG aortic stenosis undergoing TAVI. METHODS AND RESULTS: Clinical outcomes up to 5 years were addressed in the 3 groups of patients enrolled in the prospective, national, multicenter SwissTAVI registry. A total of 8914 patients undergoing TAVI at 15 heart valve centers in Switzerland were analyzed for the purpose of this study. We observed a significant difference in time to death at 1 year after TAVI, with the lowest observed in HG (8.8%) aortic stenosis, followed by P‐LFLG (11.5%; hazard ratio [HR], 1.35 [95% CI, 1.16–1.56]; P<0.001) and C‐LFLG (19.8%; HR, 1.93 [95% CI, 1.64–2.26]; P<0.001) aortic stenosis. Cardiovascular death showed similar differences between the groups. At 5 years, the all‐cause death rate was 44.4% in HG, 52.1% in P‐LFLG (HR, 1.35 [95% CI, 1.23–1.48]; P<0.001), and 62.8% in C‐LFLG aortic stenosis (HR, 1.7 [95% CI, 1.54–1.88]; P<0.001). CONCLUSIONS: Up to 5 years after TAVI, patients with P‐LFLG have higher death rates than patients with HG aortic stenosis but lower death rates than patients with C‐LFLG aortic stenosis.