Effects of Bioprosthetic Valve Fracturing on Valve-in-Valve Transcatheter Aortic Valve Implantation Transvalvular Gradients.

Background: Valve-in-valve (ViV) transcatheter aortic valve implantation (TAVI) is quickly becoming a routine and effective means by which to treat degenerated bioprosthetic valves. A known complication of ViV-TAVI is patient-prosthesis mismatch, which substantially affects survival. Bioprosthetic valve fracture is a method by which to reduce the risk of patient-prosthesis mismatch and post-ViV-TAVI transvalvular gradients. This study sought to determine the safety and efficacy of post-ViV-TAVI bioprosthetic valve fracture.

Methods: Patients with a history of surgical aortic valve replacement undergoing ViV-TAVI bioprosthetic valve fracture (N = 25) at the corresponding institution from 2015 to 2022 were cataloged for a retrospective analysis. The implanted transcatheter valves were Medtronic Evolut R, Evolut PRO, and Evolut PRO+. Gradients were assessed before and after implantation and after fracturing using transthoracic echocardiogram.

Results: The mean left ventricular ejection fraction of patients who underwent fracturing was 55.04%. The average (SD) peak and mean (SD) transvalvular gradients before the intervention were 68.17 (19.09) mm Hg and 38.98 (14.37) mm Hg, respectively. After ViV-TAVI, the same gradients were reduced to 27.25 (12.27) mm Hg and 15.63 (6.47) mm Hg, respectively. After bioprosthetic valve fracture, the gradients further decreased to 17.59 (7.93) mm Hg and 8.860 (3.334) mm Hg, respectively. The average reduction in peak gradient associated with fracturing was 12.07 mm Hg (95% CI, 5.73-18.41 mm Hg; P = .001). The average reduction in mean gradient associated with valve fracturing was 6.97 mm Hg (95% CI, 3.99-9.74 mm Hg; P < .001).

Conclusion: Bioprosthetic valve fracture is a viable option for reducing residual transvalvular gradients after ViV-TAVI and should be considered in patients with elevated gradients (>20 mm Hg) or with concern for patient-prosthesis mismatch in patients who have an unacceptable risk for a redo sternotomy and surgical aortic valve replacement.