Invasive and echocardiographic gradients of self- and balloon-expandable valves in failing aortic bioprostheses

Background Transcatheter aortic valve implantation (TAVI) is an established treatment for a failing aortic bioprosthesis. The hemodynamics of TAVI in degenerated transcatheter or surgical aortic valves (TAV-in-TAV or TAV-in-SAV) are unknown. We aimed to investigate hemodynamic differences between self- and balloon-expandable TAV-in-TAV and TAV-in-SAV groups, and transthoracic echocardiography-derived (TTE) versus invasive transaortic pressure gradients. Methods Patients ≥ 18 years with a self-expanding EVOLUT (SEV) or balloon-expandable SAPIEN3 (BEV) valve for TAV-in-TAV or TAV-in-SAV were included. Transaortic gradients were determined invasively and by TTE within 48 h post-intervention. Results We identified 56 patients with SEV ( n = 36) or BEV ( n = 20) TAV in a failing aortic bioprosthesis. Fourteen cases involved failing transcatheter valves and 42 surgical bioprostheses. Invasive mean gradients were similar after BEV and SEV (median (25th–75th percentile): 6.0 (1.5–6.5) vs 7.0 (2.0–10.0) mm Hg, p = 0.109). Mean gradients by TTE were higher for BEV than SEV at discharge (16.0 (10.8–19.8) versus 10.0 (7.0–12.0) mm Hg, p = 0.003) and 12-month follow-up (13.0 (11.0–15.5) versus 9.0 (7.0–12.3) mm Hg, p = 0.025). The discrepancy between TTE and invasive mean gradients was significantly larger for BEV than SEV (13.0 (6.3–14.0) vs 3.0 (1.5–8.3) mm Hg, p = 0.001) and most pronounced in TAV-in-SAV (BEV 13.0 (6.3–17.0) vs SEV 3.0 (1.0–8.5) mm Hg, p = 0.004). Conclusion Mean gradient after TAV in a failing bioprosthesis is similar for BEV and SEV, when measured invasively, but higher with BEV than SEV by TTE. The discordance between invasive and TTE-derived mean gradients is the largest in BEV.