Abstract
BACKGROUND: Valve-in-valve transcatheter aortic valve replacement (ViV-TAVR) has emerged as a safe, effective alternative to redo aortic valve surgery in high-risk patients with degenerated surgical bioprosthetic valves. However, ViV-TAVR has been associated high postprocedural valvular gradients, compared with TAVR for native-valve aortic stenosis. METHODS: We performed a retrospective study of all patients who underwent ViV-TAVR for a degenerated aortic valve bioprosthesis between January 1, 2013 and March 31, 2019 at our center. The primary outcome was postprocedural mean aortic valve gradient. Outcomes were compared across surgical valve type (stented versus stentless), surgical valve internal diameter (≤19 versus >19 mm), and transcatheter aortic valve type (self-expanding vs. balloon-expandable). RESULTS: Overall, 89 patients underwent ViV-TAVR. Mean age was 69.0±12.6 years, 61% were male, and median Society of Thoracic Surgeons Predicted Risk of Mortality score was 5.4 [interquartile range, 3.2-8.5]. Bioprosthesis mode of failure was stenotic (58% of patients), regurgitant (24%), or mixed (18%). The surgical valve was stented in 75% of patients and stentless in 25%. The surgical valve's internal diameter was ≤19 mm in 45% of cases. A balloon-expandable transcatheter valve was used in 53% of procedures. Baseline aortic valve area and mean gradients were 0.87±0.31 cm(2) and 36±18 mmHg, respectively. These improved after ViV-TAVR to 1.38±0.55 cm(2) and 18±11 mmHg at a median outpatient follow-up of 331 [67-394] days. Higher postprocedural mean gradients were associated with surgical valves having an internal diameter ≤19 mm (24±13 versus 16±8, P=0.002) and with stented surgical valves (22±11 versus 12±6, P<0.001). CONCLUSIONS: ViV-TAVR is an effective option for treating degenerated surgical aortic bioprostheses, with acceptable hemodynamic outcomes. Small surgical valves and stented surgical valves are associated with higher postprocedural gradients.