Matteo Sturla

Background: Among patients treated for severe aortic stenosis, a small aortic annulus could have a different impact on outcomes according to body size. We aimed to compare forward‐flow hemodynamics and clinical outcomes after transcatheter aortic valve replacement in patients with small annuli according to aortic annular area (AAA) index, defined as computed tomography‐derived AAA divided by body surface area. Methods: The TAVI‐SMALL 2 (International Multicenter Registry to Evaluate the Performance of Self‐Expandable Valves in Small Aortic Annuli 2) observational, retrospective, international cohort study enrolled patients with severe aortic stenosis and small annuli in 16 high‐volume centers between 2011 and 2020. Analyses comparing patients with low (ie, ≤2 cm ² /m ² ) and high AAA index (ie, >2 cm ² /m ² ) were conducted adopting propensity score methodology. Primary end points were predischarge device forward‐flow composite (including mean aortic gradient ≥20 mm Hg or severe prosthesis–patient mismatch), and clinical efficacy composite (including all‐cause death, transient ischemic attack/stroke, or hospitalization for heart failure) at 1‐year follow‐up. Results: A total of 1256 patients were included in the analysis. In the 1:1 propensity score–matched population (n=688), the primary predischarge forward‐flow composite end point occurred in 48 patients (7.5%) overall and was more common in low versus high AAA index (9.7% versus 5.3%, P =0.034). The primary composite clinical efficacy end point occurred in 95 patients (18.1%), and no difference between groups was observed at 1‐year follow‐up (11.5% [95% CI, 7.8%–16.8%] versus 14.4% [95% CI, 10.4%–19.9%], hazard ratio, 0.89 [95% CI, 0.59–1.33]; P _log‐rank =0.842). Conclusions: Among patients with small aortic annuli undergoing transcatheter aortic valve replacement, the novel AAA index further identifies patients at increased risk of predischarge suboptimal forward‐flow hemodynamics. No difference in clinical efficacy at 1‐year follow‐up was observed according to the AAA index.