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.