Background: Bioprosthetic valve fracture (BVF) is a technique to reduce transvalvular gradients in valve-in-valve transcatheter aortic valve replacement (VIV-TAVR) procedures. Outcome of VIV-TAVR with BVF has not been compared with VIV-TAVR without BVF. Aim of this study was to evaluate the outcome of VIV-TAVR with BVF compared with VIV-TAVR without BVF in cohorts with comparable baseline characteristics. 

Methods: Fourteen international centers provided data of BVF-VIV-TAVR procedures in patients with degenerated surgical aortic valves (SAVs) with fracturable or dilatable sewing rings. Patients with VIV-TAVRs performed in the same time period in SAVs, which were suitable for, but did not undergo BVF, served as a control-group. Data were collected retro- and prospectively.

Results: 81 cases of BVF-VIV-TAVR (BVF-group) were compared with 79 cases of VIV-TAVR without BVF (control-group). Baseline characteristics were comparable with the exception of more male patients (65 vs 42%, p=0.004), larger SAVs (24.1±2.4 vs 22.1±2.1, p<0.001) and true internal diameters (20.7 ± 2.5mm vs 19.1 ± 1.8, p < 0.001) in the control-group. 

VARC-2 defined device success was 93% in the BVF- and 68.4% in the control-group (p<0.001). The main reason for procedure failure was a residual mean transvalvular gradient ³ 20mmHg in both groups, which was found in 5 of 6 failures in the BVF- and in 22 of 25 failures in the control-group (p<0.001). The mean transvalvular gradient decreased from 37 ± 13mmHg to 10.8 ± 5.9mmHg (p<0.001) in the BVF- and from 35 ± 16mmHg to 15.8 ± 6.8mmHg (p<0.001) in the control-group with a significantly higher final transvalvular gradient in the control-group (p<0.001). Transvalvular gradients did not significantly change over time. In-hospital major adverse events occurred in 3.7% in BVF- and 7.6% in control-group (p=0.325). A linear mixed model identified BVF, self-expanding transcatheter heart valves (THVs) and SAV types other than Mitroflow as predictors for lower transvalvular gradients.

Conclusions: Compared with VIV-TAVR alone, VIV-TAVR with BVF resulted in a significantly lower transvalvular gradient acutely and at follow-up. Independent predictors for lower gradients were the use of self-expanding THVs and the treatment of SAVs other than Mitroflow, irrespective of BVF-performance. BVF significantly reduced the gradient independently from transcatheter or surgical valve type.