High Residual Gradient Following a Self-Expandable Transcatheter Aortic Valve-in-Valve Implantation - Risk Factor Analysis, Outcomes, and Survival.

INTRODUCTION: Transcatheter aortic valve-in-valve implantation (TAVI-ViV) can be associated with unfavorable hemodynamic outcomes. This study aimed to estimate the prevalence, identify the risk factors, and evaluate the outcomes and survival of patients with high residual gradients after TAVI-ViV. METHODS: A total of 85 patients were included in the study. The cohort was divided into group A, with postprocedural mean pressure gradient (PG) ≥ 20 mmHg, and group B, with mean PG < 20 mmHg. RESULTS: Postprocedural PG ≥ 20 mmHg was observed in 24.7% of the patients. In a univariate analysis, preoperative gradient, pre-existing patient-prosthesis mismatch (PPM), deep valve implantation, small degenerated valves, and an older generation of transcatheter aortic valves were found to be risk factors for high residual gradient. Multivariate analysis showed that preexisting maxPG > 60 mmHg, implantation level of 4 mm below neo-annulus, and degenerated valve size ≤ 23 mm were independent predictors of high residual gradient. There were no differences in early morbidity (myocardial infarction, pacemaker implantation, stroke, acute renal insufficiency) between groups. Kaplan-Meier estimated that the survival rate was comparable at one and five years regardless of postoperative gradient. Survivors with high residual mean gradient were significantly affected by a high New York Heart Association (NYHA) class. CONCLUSION: High residual transvalvular gradient after TAVI-ViV is not rare, but it does not significantly affect mortality. High residual mean gradient has a negative impact on NYHA functional class improvement after the procedure. High preoperative gradient, implantation level, and small failed bioprosthesis may predispose to increased residual gradient.