Three-Year Survival Comparison between Transcatheter and Surgical Aortic Valve Replacement for Intermediate- and Low-Risk Patients

Five-year outcomes in trials comparing transcatheter aortic valve implantation versus surgical aortic valve replacement: a pooled meta-analysis of reconstructed time-to-event data

OBJECTIVES

The incidence of outcomes in trials comparing transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) is expected to be different in the short and long term. We planned a meta-analysis of reconstructed time-to-event data from trials comparing TAVI and SAVR to evaluate their time-varying effects on outcomes.

METHODS

We performed a systematic review of the literature from January 2007 through September 2021 on Medline, Embase, the Cochrane Central Register of Controlled Trials and specialistic websites, including randomized trials with allocation to TAVI or SAVR that reported at least 1-year follow-up and that graphed Kaplan-Meier curves of end points. The comparisons were done with grouped frailty Cox models in a landmark framework and fully parametric models.

RESULTS

Seven trials were included (7770 participants). TAVI showed a lower incidence of the composite of death or stroke in the first 6 months [risk-stratified hazard ratio (HR) 0.66, 95% confidence interval (CI) 0.56-0.77, P-value <0.001], with an HR reversal after 24 months favouring SAVR (risk-stratified HR 1.25; 95% CI 1.08-1.46; P-value 0.003). These outcomes were confirmed for all-cause death (risk-stratified HR after 24 months 1.18; 95% CI 1.03-1.35; P-value 0.01). TAVI was also associated with an increased incidence of rehospitalization after 6 months (risk-stratified HR 1.42; 95% CI 1.06-1.91; P-value 0.018) that got worse after 24 months (risk-stratified HR 1.67; 95% CI 1.24-2.24; P-value <0.001).

CONCLUSIONS

Although it could appear that there is no difference between TAVI and SAVR in the 5-year cumulative results, TAVI shows a strong protective effect in the short term that runs out after 1 year. TAVI becomes a risk factor for all-cause mortality and the composite end point after 24 months and for rehospitalization after 6 months.

Mortality in trials on transcatheter aortic valve implantation versus surgical aortic valve replacement: a pooled meta-analysis of Kaplan-Meier-derived individual patient data

OBJECTIVES

This meta-analysis of Kaplan-Meier-estimated individual patient data was designed to evaluate the effects of transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) on the long-term all-cause mortality rate, to examine the potential time-varying effect and to model their hazard ratios (HRs) over time. Moreover, we sought to compare traditional meta-analytic tools and estimated individual patient data meta-analyses.

METHODS

Trials comparing TAVI versus SAVR were identified through Medline, Embase, Cochrane databases and specialist websites. The primary outcome was death from any cause at follow-up. Enhanced secondary analyses of survival curves were performed estimating individual patient time-to-event data from published Kaplan-Meier curves. Treatments were compared with the random effect Cox model in a landmark framework and fully parametric models.

RESULTS

We identified 6 eligible trials that included 6367 participants, randomly assigned to undergo TAVI (3252) or SAVR (3115). According to the landmark analysis, the incidence of death in the first year after implantation was significantly lower in the TAVI group [risk-profile stratified HR 0.85, 95% confidence interval (CI) 0.73-0.99; P = 0.04], whereas there was a reversal of the HR after 40 months (risk-profile stratified HR 1.31, 95% CI 1.01-1.68; P = 0.04) favouring SAVR over TAVI. This time-varying trend of HRs was also confirmed by a fully parametric time-to-event model. Traditional meta-analytic tools were shown to be biased because they did not intercept heterogeneity and the time-varying effect.

CONCLUSIONS

The mortality rates in trials of TAVI versus SAVR are affected by treatments with a time-varying effect. TAVI is related to better survival in the first months after implantation whereas, after 40 months, it is a risk factor for all-cause mortality.

Transcatheter aortic valve implantation versus surgical aortic valve replacement in patients at low and intermediate risk: A risk specific meta-analysis of randomized controlled trials

Background

Transcatheter aortic valve implantation (TAVI) is an option for treatment for patients with severe aortic stenosis who are at high risk for death with surgical aortic valve replacement (SAVR). It is unknown whether TAVI can be safely introduced to intermediate- and low-risk patients.

Objective

To compare the efficacy and safety of TAVI and SAVR in patients with intermediate- and low-surgical risk.

Data sources

Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched from inception to April 15, 2019.

Study selection

We included randomized controlled trials comparing TAVI with SAVR in patients with intermediate- and low-surgical risk.

Data extraction

Meta-analyses were conducted using random-effects models to calculate risk ratios (RR) with corresponding 95% confidence interval (CI). Two independent reviewers completed citation screening, data abstraction, and risk assessment. Primary outcome was a composite of all-cause mortality or disabling stroke at 12 months.

Data Synthesis

A total of 5 trials randomizing 6390 patients were included. In patients with low risk, TAVI was associated with a significant reduction in the composite of all-cause mortality or disabling stroke compared with SAVR (RR, 0.56; 95%CI, 0.40–0.79; I² = 0%). This benefit was not replicated in patients with intermediate risk (RR, 0.96; 95% CI, 0.80–1.15; I² = 0%). Similar results were seen separately in all-cause mortality and disabling stroke when TAVI was compared with SAVR.

Conclusion

For patients with severe aortic stenosis who were at low risk for death from surgery, TAVI achieved superior clinical outcomes compared to SAVR; however, these benefits were not seen in those with intermediate risk. This information may inform discussions about deciding between SAVR and TAVI for patients with low to intermediate risk separately.