High residual gradients after transcatheter aortic valve implantation in raphe-type bicuspid aortic valve stenosis: insights from the AD-HOC registry.

Background: Bicuspid aortic valve (BAV) stenosis poses several challenges when transcatheter aortic valve implantation (TAVI) is performed, including the risk of high residual gradients (HRG).

Objective: To identify incidence, predictors and outcomes of HRG after TAVI in Sievers type 1 BAV stenosis.

Methods: Consecutive patients with Sievers type 1 BAV stenosis undergoing TAVI at 24 international centers from 2016 to 2023 were enrolled. HRG were defined as a mean transvalvular gradient ≥ 20 mmHg at 30 days, according to Valve Academic Research Consortium-3 (VARC-3) criteria. The primary endpoint was major adverse cardiovascular events (MACE), defined as a composite of all-cause death, neurologic events or hospitalization for heart failure, assessed at 3 years after TAVI. Secondary endpoints included the single components of the primary outcome. Endpoints were assessed according to the presence of HRG, before and after covariate adjustment for clinically relevant confounders.

Results: A total of 972 patients were enrolled. HRG post-TAVI were found in 35 patients (3.6%). Patients with HRG had a higher preprocedural aortic valve gradient (57.0 [interquartile range: 49.0-69.0] mmHg vs 48.0 [40.0-58.0] mmHg, p < 0.001) and received smaller transcatheter heart valve (THV) (26.0 [23.0-29.0] mm vs 29.0 [26.0-29.0] mm, p < 0.001) when compared to patients with normal residual gradients (NRG). The only independent predictor of HRG was a bioprosthesis size ≤ 23 mm. At 3 years, MACE occurred in 35.0% of HRG patients and 22.3% of NRG patients (adjusted hazard ratio [HR]: 2.41, 95% confidence interval [CI]: 1.15-5.04; p = 0.019). HRG patients had a higher risk of neurologic events as compared to NRG patients (13.3% versus 4.5%, adjusted HR: 4.50, 95% CI: 1.52-13.30, p = 0.007).

Conclusions: After TAVI in Sievers type 1 BAV stenosis, HRG occurred in around 4% of cases and were associated with an increased risk of MACE and neurologic events.