Meta-analysis of longitudinal comparison of transcatheter versus surgical aortic valve replacement in patients at low to intermediate surgical risk
Authors: Ahmed Mushood , Ahsan Areeba , Shafiq Aimen , Nadeem Zain A. , Arif Fariha , Zulfiqar Eeshal , Kazmi Muhammad H. , Yadav Rukesh , Jain Hritvik , Ahmed Raheel , Alam Mahboob , Shahid Farhan 
Published: November 2024

Background:
Surgical aortic valve replacement (SAVR) is the commonly used approach for aortic valve replacement (AVR) in patients with aortic stenosis at low or intermediate surgical risk. However, transcatheter aortic valve replacement (TAVR) has emerged as an alternative to SAVR for AVR. This meta-analysis aims to assess the comparative efficacy and safety of TAVR versus SAVR in low-to-intermediate surgical risk patients by analyzing temporal trends in the outcomes of TAVR and SAVR at various follow-up intervals, providing a more detailed understanding.

Methods:
A thorough literature search was performed across PubMed/MEDLINE, Embase, and the Cochrane Library from their inception up to May 2024 to identify eligible randomized controlled trials (RCTs). Clinical outcomes were evaluated using a random-effects model to pool risk ratios (RRs) with 95% CIs.

Results:
A total of 17 studies reporting data at different follow-ups for nine trials were included (n=9092). No statistically significant difference was observed between TAVR and SAVR for reducing all-cause death at 30 days, 1 year, and 2 years but significantly increased risk with TAVR at 5 years or longer follow-up (RR=1.13, 95% CI: 1.03–1.23). However, TAVR was associated with a significantly decreased risk for cardiac death at 1-year follow-up (RR=0.79, 95% CI: 0.64–0.96) and comparable risk for cardiac death at 30 days, 2 years, and 5 years or longer follow-up when compared with SAVR. No statistically significant difference was observed between TAVR and SAVR for reducing the risk of myocardial infarction (MI) at 30 days, 1 year, 2 years, and 5 years or longer follow-up.
TAVR was associated with a significantly lower risk of major bleeding events at 30 days (RR=0.38, 95% CI: 0.21–0.67); lower risk of acute kidney injury (AKI) at 30 days (RR=0.38, 95% CI: 0.26–0.54) and 1 year (RR=0.58, 95% CI: 0.41–0.82) and lower risk of new onset or worsening atrial fibrillation (AF) at 30 days (RR=0.25, 95% CI: 0.18–0.34), 1 year (RR=0.26, 95% CI: 0.16–0.41) and 2 years (RR=0.32, 95% CI: 0.20–0.49) when compared with SAVR. However, TAVR was associated with a significantly increased risk of permanent pacemaker implantation (PPI) at 30 days (RR: 2.62, 95% CI: 1.40–4.91), at 1 year (RR: 2.19, 95% CI: 1.24–3.87), at 2 years (RR: 2.74, 95% CI: 1.31–5.71), and beyond 5 years (RR: 1.95, 95% CI: 1.20–3.15). TAVR was also associated with a significantly increased risk of prosthetic valve thrombosis at 2 years (RR=2.70, 95% CI: 1.08–6.71), though no significant association was observed at 30 days, 1 year, or 5 years. Similarly, no significant differences were observed in aortic-valve reintervention rates at 30 days, 2 years, or 5 years, but TAVR showed a significantly increased risk at 1 year (RR=1.98, 95% CI: 1.21–3.24). TAVR was associated with a significantly increased risk of major vascular complications at 30 days (RR=2.37, 95% CI: 1.38–4.04) and a significantly increased risk of TIA at 2 years (RR: 1.43, 95% CI: 1.02–2.00, I
2=0%). The risk of hospitalizations was comparable between the groups.

Conclusion:
TAVR and SAVR demonstrated comparable rates of all-cause death up to 2 years of follow-up. However, at 5 years or longer follow-up, TAVR was associated with a higher risk of all-cause death. While TAVR showed certain procedural advantages, such as a lower risk of major bleeding, AKI, and new-onset or worsening AF, the choice between TAVR and SAVR in patients with low or intermediate surgical risk should consider long-term outcomes, with SAVR potentially being more favorable due to better survival observed on longer follow-up durations.