Does Anatomy Dictate Outcome?: Self-Expanding vs Balloon-Expandable Transcatheter Aortic Valve Replacement in Small...

The optimal transcatheter aortic valve replacement strategy in patients with a small aortic annulus (SAA) remains unclear. We performed a systematic review and meta-analysis comparing self-expanding valves (SEVs) to balloon-expandable valves (BEVs) in SAA patients. We searched PubMed, Embase, Web of Science, and Scopus for studies comparing SEVs and BEVs in patients with SAA defined by computed tomography. A random-effects model using the Der Simonian and Laird estimator was used to pool odds ratios (ORs) and mean differences (MDs). We identified 25 studies encompassing 13,846 patients (5633 BEV; 8213 SEV). SEVs demonstrated superior hemodynamics, including a larger indexed effective orifice area (MD: 0.20 cm2/m2; P < 0.00001), a lower mean transvalvular gradient (MD: -4.11 mm Hg; P < 0.00001), and a lower risk of severe patient-prosthesis mismatch (OR: 0.37; P < 0.00001). However, SEVs were associated with a higher risk of permanent pacemaker implantation (PPI) (OR: 1.63; P = 0.0008) and moderate or severe paravalvular leak (PVL) (OR: 2.26; P < 0.00001). There was no significant difference in all-cause mortality at 1 year (OR: 0.96; P = 0.55) or stroke at 30 days (OR: 1.34; P = 0.18). Notably, in a subgroup analysis restricted to patients with extra-small annuli (area <400 mm2 or diameter <23 mm), the hemodynamic advantages of SEVs persisted while the elevated risks of PPI and PVL were no longer statistically significant. In patients with SAA, SEVs provide better hemodynamics but carry safety concerns including higher risks of PVL and PPI in the overall population. These risks were not observed in the extra-small annulus subgroup. Valve selection should be individualized based on patient anatomy and procedural risk profile.