Transcatheter Aortic Valve Implantation for Treatment of Aortic Valve Stenosis: A Health Technology Assessment.

Background: Surgical aortic valve replacement (SAVR) is the gold standard for treating aortic valve stenosis. It is a major operation that requires sternotomy and the use of a heart-lung bypass machine, but in appropriately selected patients with symptomatic, severe aortic valve stenosis, the benefits of SAVR usually outweigh the harms. Transcatheter aortic valve implantation (TAVI) is a less invasive procedure that allows an artificial valve to be implanted over the poorly functioning valve.

Methods: We identified and analyzed randomized controlled trials that evaluated the effectiveness and safety of TAVI compared with SAVR or balloon aortic valvuloplasty and were published before September 2015. The quality of the body of evidence for each outcome was examined according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. The overall quality was determined to be high, moderate, low, or very low using a step-wise, structural methodology. We also developed a Markov decision-analytic model to assess the cost-effectiveness of TAVI compared with SAVR over a 5-year time horizon, and we conducted a 5-year budget impact analysis.

Results: Rates of cardiovascular and all-cause mortality were similar for the TAVI and SAVR groups in all studies except one, which reported significantly lower all-cause mortality in the TAVI group and a higher rate of stroke in the SAVR group. Trials of high-risk patients who were not suitable candidates for SAVR showed significantly better survival with TAVI than with balloon aortic valvuloplasty. Median survival in the TAVI group was 31 months, compared with 11.7 months in the balloon aortic valvuloplasty group. Compared with SAVR, TAVI was associated with a significantly higher risk of stroke, major vascular complications, paravalvular aortic regurgitation, and the need for a permanent pacemaker. SAVR was associated with a higher risk of bleeding. Transapical TAVI was associated with higher rates of mortality and stroke than transfemoral TAVI in high-risk patients. TAVI and SAVR both improved patients' quality of life during the first year. However, because of a large amount of missing data and the lack of published data beyond 1 year, it was difficult to evaluate the impact of critical adverse outcomes on patients' longer-term health status. In the base-case analysis, when TAVI was compared with SAVR, the incremental cost-effectiveness ratio was $51,988 per quality-adjusted life-year. The 5-year budget impact of funding TAVI ranged from $7.6 to $8.3 million per year.

Conclusions: Moderate quality evidence showed that TAVI and SAVR had similar mortality rates in patients who were eligible for surgery. Information about quality of life showed similar results for TAVI and SAVR in the first year, but was based on low quality evidence. Moderate quality evidence also showed that TAVI was associated with higher rates of adverse events than SAVR. In patients who were not suitable candidates for surgery, moderate quality evidence showed that TAVI improved survival compared with balloon aortic valvuloplasty. When TAVI was compared with SAVR, the incremental cost-effectiveness ratio was $51,988 per quality-adjusted life-year.