Abstract Body (Do not enter title and authors here): Background:
Transcatheter aortic valve replacement (TAVR) is an effective percutaneous intervention in patients with severe aortic stenosis, particularly in those with contraindications for surgical repair. Currently, two types of aortic valves are used in clinical practice: balloon-expanding valves (BEV) and self-expanding valves (SEV). The current data comparing early (30-day) clinical outcomes of BEV to SEV in patients with severe aortic stenosis undergoing TAVR are inconsistent.

Methods:
A systematic literature search spanning PubMed, Embase, Cochrane, and Scopus databases was conducted to retrieve randomized controlled trials (RCTs) comparing balloon-expanding valves to self-expanding valves in patients undergoing TAVR. The DerSimonian and Laird random-effects model was used to pool the odds ratios (OR) with 95% confidence intervals. Statistical significance was set at p<0.05.

Results:
This meta-analysis included five RCTs with 2190 severe aortic stenosis patients (1097 in the BEV group and 3621 in the SEV group). BEV-TAVR was associated with a significantly lower risk of 30-day new permanent pacemaker (PPM) implantation [OR: 0.67; 95% CI: 0.48, 0.93; p=0.02] and 30-day re-hospitalization for heart failure [OR: 0.20; 95% CI: 0.04, 0.96; p=0.04] compared to SEV-TAVR. The risks of 30-day mortality, 30-day cardiac mortality, 30-day all-cause stroke, 30-day myocardial infarction, 30-day life-threatening bleeding, 30-day vascular complications, 30-day acute kidney injury, and 30-day repeat procedures for valve-related dysfunction were comparable between the two groups.

Conclusion:
TAVR in patients with severe aortic stenosis using BEV is advantageous over SEV in terms of 30-day new PPM implantation and 30-day rehospitalization for heart failure, with comparable risks for other outcomes. These findings underscore the safety and efficacy of newer generation valves, including Sapien 3 and EvolutPro, in TAVR. The choice of prosthetic aortic valve is dependent on individual anatomy and operator preference. Further RCTs are warranted to evaluate other newer-generation valves with varying severities of aortic stenosis.