Transcatheter aortic valve implantation: evidence on safety and efficacy compared with medical therapy. A systematic review of current literature.

OBJECTIVES: Transcatheter aortic valve implantation (TAVI) promises effective treatment for high-risk elderly patients with symptomatic severe aortic stenosis (AS). However, the adoption of TAVI must be justified and guarantee long-term performance. Systematic reviews are a core methodology in evidence-based health economics for judging medical effectiveness. In this work, the methodology was applied to provide objective evidence on the efficacy and safety of TAVI at 1-year follow-up and to assess whether TAVI confers a survival benefit compared with medical therapy.
METHODS: In accordance with the toolkit of the "German Scientific Working Group Technology Assessment for Health Care" (GSWG), a systematic literature review on the safety and efficacy of TAVI procedures was conducted in major bibliographic databases to identify all relevant publications. Preestablished inclusion criteria were defined. An initial screening of identified articles regarding titles and abstracts was followed by a full-text screening. Data from eligible articles were extracted and evaluated according to GSWG checklists followed by a qualitative synthesis of information.
RESULTS: The systematic literature search identified 12 primary publications (derived from 1,849 citations) for TAVI [number of patients (n) = 1,049] and 11 publications (derived from 189 citations) for medical therapy of AS (n = 946) that fulfilled the inclusion criteria. Mean overall procedural success rate for included TAVI interventions was 93.3%. Mean combined procedural, post-procedural, and cumulative in-hospital/30-day mortality was 11.4% (n = 116; range 5.3-23%). 1 year after TAVI, the mean overall survival rate was 75.9% (range 64.1-87%) compared with 62.4% (range 40-84.8%) for medically treated patients (p value < 0.01). 1-year survival after TAVI for patients treated with transvascular (TV) procedures was higher than after transapical (TA) procedures (79.2 vs. 73.6%) (p value = 0.04). At 1-year follow-up, the improved valvular function remained stable, and there was a trend towards an improved ventricular function.
CONCLUSION: Based on the best available data, in patients with symptomatic severe AS, TAVI demonstrates an improved 1-year survival compared with medical treatment. The survival benefit of TV-TAVI over medical therapy elucidated from this systematic literature review is +16.8% and therefore, in good congruence with the recently published results from the randomized PARTNER US trial (+20%).