Transcatheter versus surgical aortic valve replacement in lower-risk patients: an updated meta-analysis of randomised controlled trials
Authors: Reddy R K , Howard J P , Reardon M J , Thyregod H G H , Jorgensen T H , Toff W D , Forrest J K , Leon M B , Ahmad Y 
Published: October 2024

Abstract

Background
Long-term clinical outcomes after transcatheter [TAVI] and surgical [SAVR] aortic valve replacement are of utmost importance in lower-risk patients. Event rates are diminished in lower-risk patients, therefore individual trials may be separately underpowered to assess low-frequency outcomes. New randomised data has emerged, including 4, 5 and 10-year follow-up from the Evolut Low Risk, PARTNER-3 and NOTION trials, respectively.

Purpose
To perform a systematic review and meta-analysis of randomised trials studying long-term outcomes in patients with severe aortic stenosis at low-surgical risk undergoing TAVI versus SAVR.

Methods
Trials randomising patients at lower surgical risk in trials comparing TAVI with SAVR were systematically identified. The prespecified primary endpoint was all-cause death. Key secondary endpoints included stroke, death or disabling stroke, cardiac death, new permanent pacemaker, aortic valve reintervention, and new-onset atrial fibrillation. Reconstructed individual patient data [IPD] was obtained via digitisation of Kaplan-Meier survival curves. Using these data, Cox proportional hazards regression was performed using frailty models on the primary outcome of all-cause death. To assess total lifetime lost, the restricted mean survival time [RMST] was calculated. Conventional pairwise random effects meta-analyses were also performed. This analysis was prospectively registered [CRD42023484976].

Results
4 eligible trials contributed data from 3557 patients with a weighted mean follow-up duration of approximately 4 years (47.6 months). In the reconstructed IPD pooled analyses, there was no significant difference in the hazard of death [hazard ratio 1.15, 95% CI 0.93 to 1.41, p=0.20] or RMST [Δ-0.8 months, p=0.09] (Figure 1). In pairwise meta-analyses, there was no difference between TAVI and SAVR in all-cause death [relative risk (RR) 0.94, 95% confidence interval (CI) 0.78 to 1.13, p=0.51] (Figure 2). There was also no significant difference for stroke [RR 0.94, 95% CI 0.59 to 1.50, p=0.80], or a composite of death or disabling stroke [RR 0.92, 95% CI 0.70 to 1.22, p=0.57]. There was an increase in new pacemaker implantation with TAVI [RR 2.15, 95% CI 1.50 to 3.07, p&lt;0.001], and a reduction in new AF with TAVI [RR 0.43, 95% CI 0.26 to 0.70, p&lt;0.001]; there was no significant difference in any other endpoint (Figure 2).

Conclusions
The present analysis demonstrates no difference in major clinical outcomes with TAVI or SAVR in lower-risk patients at 4-years follow-up. These results were consistent when analysed using pooled reconstructed IPD or conventional meta-analyses and there were no differences in RMST. These data are informative for lower-risk patients and clinicians, but longer-term follow-up is required to confirm whether equivalence is maintained.Kaplan-Meier plot comparing TAVI vs SAVRForest plot for key clinical endpoints