Transcatheter Aortic Valve Implantation Outcomes and Challenges in Asia: A Systematic Review and Meta-Analysis

Abstract

Background: Aortic stenosis (AS) is the world's most prevalent heart valve disease. Transcatheter aortic valve replacement (TAVR) or Implantation (TAVI) is widely available yet adopting this procedure in Asia has been slow due to high device cost, the need for specific training programs, and the lack of specialized heart teams and dedicated infrastructures. The limited number of randomized controlled trials describing TAVI outcomes among the Asian population hampered the approval for medical reimbursements as well as acceptance among surgeons and operators in some Asian countries.

Methods: A comprehensive medical literature search on TAVI and/or TAVR performed in Asian countries published between January 2015 and June 2022 was done through MEDLINE and manual searches of bibliographies. The full text of eligible articles was obtained and evaluated for final analysis. The event rates for key efficacy and safety outcomes were calculated using the data from the registries and randomized controlled trials.

Results: A total of 15,297 patients were included from 20 eligible studies. The mean patient age was 82.88 $\pm$ 9.94 years, with over half being females (62.01%). All but one study reported Society of Thoracic Surgeons (STS) scores averaging an intermediate risk score of 6.28 $\pm$ 1.06%. The mean logistic European Systems for Cardiac Operations Risk Evaluation (EuroSCORE) was 14.85. The mean baseline transaortic gradient and mean aortic valve area were 50.93 $\pm$ 3.70 mmHg and 0.64 $\pm$ 0.07 ${\mathrm{cm}}^2$ , respectively. The mean procedural success rate was 95.28 $\pm$ 1.51%. The weighted mean 30-day and 1-year all-cause mortality rate was 1.66 $\pm$ 1.21% and 8.79 $\pm$ 2.3%, respectively. The mean average for stroke was 1.98 $\pm$ 1.49%. The acute kidney injury (AKI) rate was 6.88 $\pm$ 5.71%. The overall major vascular complication rate was 2.58 $\pm$ 2.54%; the overall major bleeding rate was 3.88 $\pm$ 3.74%. Paravalvular aortic regurgitation rate was 15.07 $\pm$ 9.58%. The overall rate of pacemaker insertion was 7.76 $\pm$ 4.6%.

Conclusions: Compared to Americans and Europeans, Asian patients who underwent TAVI had lower all-cause mortality, bleeding, and vascular complications, however, had a higher rate of postprocedural aortic regurgitation. More studies with greater sample sizes are needed among Asian patients for a more robust comparison.

Keywords: Asia; TAVI; TAVR; aortic stenosis; aortic valve; outcomes; transcatheter.

Fig. 1.

PRISMA flow diagram. Study flow based on the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P).

Fig. 2.

Distribution of studies.

Fig. 3.

Procedural success. Forest plot on the rates of procedural success as an outcome of TAVR performed in Asian patients.

Fig. 4.

In-hospital mortality. Forest plot showing rates of in-hospital mortality as an outcome of TAVR performed in Asian patients.

Fig. 5.

30-day mortality. Forest plot showing rates of 30-day Mortality as an outcome of TAVR performed in Asian patients. Abbreviations: TAVR, Transcatheter aortic valve replacement.

Fig. 6.

1-year mortality. Forest plot showing rates of one-year mortality as an outcome of TAVR performed in Asian patients. Abbreviations: TAVR, Transcatheter aortic valve replacement.

Fig. 7.

Stroke. Forest plot showing rates of stroke as an outcome of TAVR performed in Asian patients. Abbreviations: TAVR, Transcatheter aortic valve replacement.

Fig. 8.

Acute kidney injury (AKI). Forest plot showing rates of AKI as an outcome of transcatheter aortic valve replacement (TAVR) performed in Asian patients.

Fig. 9.

Major vascular complication. Forest plot showing rates of major vascular complications as an outcome of TAVR performed in Asian patients. Abbreviations: TAVR, Transcatheter aortic valve replacement.

Fig. 10.

Major bleeding. Forest plot showing rates of major bleeding as an outcome of TAVR performed in Asian patients. Abbreviations: TAVR, Transcatheter aortic valve replacement.

Fig. 11.

Perivalvular aortic regurgitation. Forest plot showing rates of perivalvular aortic regurgitation as an outcome of transcatheter aortic valve replacement (TAVR) performed in Asian patients.

Fig. 12.

Permanent pacemaker insertion. Forest plot showing rates of PPI as an outcome of TAVR performed in Asian patients. Abbreviations: PPI, permanent pacemaker implantation; TAVR, Transcatheter aortic valve replacement.

Fig. 13.

Percentage of the population ages 65 and older.