This section describes efficacy outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview.
The evidence on efficacy is presented separately for 2 different indications: first for degenerated aortic surgical bioprostheses and second for rescue of suboptimal transcatheter aortic valve implantation (TAVI).
Transcatheter ViV implantation in degenerated aortic surgical bioprostheses
4.1 A register of 47 patients treated by valve-in-valve transcatheter aortic valve implantation (ViV‑TAVI) reported implantation success of 100% and short-term procedural success of 98% (46/47). Implantation success was defined as successful implantation into the failed surgical prosthesis (procedural success was not defined).
4.2 In a register of 459 patients who were treated by ViV‑TAVI for degenerated bioprosthetic valves, the 1‑year survival rate calculated using a Kaplan–Meier curve was 83% (228/459; 95% confidence interval [CI] 81.8 to 84.7%). Factors associated with mortality within 1 year included small size of the original surgical bioprosthesis (<21 mm; hazard ratio [HR] 2.04; 95% CI 1.14 to 3.67; p=0.02) and aortic stenosis before intervention (compared against regurgitation, HR 3.07; 95% CI 1.33 to 7.08; p=0.008).
4.3 The register of 459 patients treated by ViV‑TAVI for degenerated bioprosthetic valves reported improvement in New York Heart Association (NYHA) functional class after the procedure. Before treatment, 8% (35/459) of patients were in class I/II, compared with 93% (313/459) at 30‑day follow up. Before treatment 92% (424/459) of patients were class III/IV compared with 7% (25/338) at 30 days. These results were maintained at 1‑year follow-up.
4.4 The register of 47 patients reported that there was an improvement in the mean transvalvular pressure gradient (from 38±15 mmHg to 17±10 mmHg, significance not reported) and an increase in mean aortic valve area (from 0.90±0.42 cm2 to 1.61±0.47 cm2, p<0.001) after ViV‑TAVI implantation.
Transcatheter ViV implantation for rescue of suboptimal TAVI
4.5 A register of 663 patients, including 24 patients treated by transcatheter ViV for aortic bioprosthesis malposition reported procedural success in all patients treated by ViV‑TAVI. For the 24 patients treated by ViV‑TAVI, the register reported survival of 23 patients (96%) and an improvement in the mean transaortic gradient in all 24 patients (from 45.4±14.8 mmHg to 10.5±5.2 mmHg, p=0.83) at 1‑year follow-up.
4.6 The specialist advisers listed additional key efficacy outcomes as mid- and long-term survival, long-term durability and quality of life.