The anatomic substrate of bicuspid valves may lead to suboptimal TAVR stent expansion and geometry.
We evaluated determinants of stent geometry in bicuspid valves treated with Sapien transcatheter aortic valve replacement (TAVR) valves.
A multicenter retrospective registry of patients (February 2019 to August 2022) who underwent post-TAVR computed tomography to determine stent area (vs. nominal valve area) and stent ellipticity (maximum diameter/minimum diameter). Predictors of relative stent expansion (minimum area/average of inflow + outflow area) and stent ellipticity were evaluated in a multivariable regression model, including valve calcium volume (indexed by annular area), presence of raphe calcium, sinus diameters indexed by area-derived annular diameter, and performance of pre-dilation and post-dilation.
The registry enrolled 101 patients from four centers. The minimum stent area (vs. nominal area) was 88.1%, and the maximum ellipticity was 1.10, with both observed near the midframe of the valve in all cases. Relative stent expansion ≥90% was observed in 64/101 patients. The only significant predictor of relative stent expansion ≥90% was the performance of post-dilation (OR: 4.79, p = 0.018). Relative stent expansion ≥90% was seen in 86% of patients with post-dilation compared to 57% without (p < 0.001). The stent ellipticity ≥1.1 was observed in 47/101 patients. The significant predictors of stent ellipticity ≥1.1 were the indexed maximum sinus diameter (OR: 0.582, p = 0.021) and indexed intercommisural diameter at 4 mm (OR: 2.42, p = 0.001). Stent expansion has a weak negative correlation with post-TAVR mean gradient (r = -0.324, p < 0.001).
Relative stent expansion ≥90% was associated with the performance of post-dilation, and stent ellipticity ≥1.1 was associated with indexed intercommisural diameter and indexed maximum sinus diameter. Further studies to determine optimal deployment strategies in bicuspid valves are needed.