Aims: The elastic behaviour (acute recoil) of a valve prosthesis stent following transcatheter aortic valve implantation (TAVI) is unknown. This study sought to determine the occurrence, severity, predictive factors and haemodynamic consequences of acute recoil following TAVI.
Methods and results: A prospective angiographic analysis of the stent frame dimensions in 111 consecutive patients who underwent TAVI with a balloon-expandable valve (36 Edwards SAPIEN; 75 SAPIEN XT) was performed. Acute recoil was defined as the difference between minimal lumen diameter (MLD) at full balloon expansion and immediately after balloon deflation. MLD during balloon inflation was significantly larger than MLD after balloon deflation (23.40±2.31 mm vs. 22.29±2.21 mm, p<0.001), which represented an absolute and percent decrease in stent dimension of 1.10±0.40 mm and 4.70±1.76%, respectively. In the multivariate analysis, the predictors of larger recoil were a higher prosthesis/annulus ratio (r²=0.0624, p=0.015) and the SAPIEN XT prosthesis (r²=0.1276, p=0.001). No significant changes in haemodynamic performance were observed at discharge and follow-up in patients with larger recoil.
Conclusions: TAVI with a balloon-expandable valve was systematically associated with a certain degree of valve stent recoil after balloon deflation. A higher degree of valve oversizing and the SAPIEN XT prosthesis predicted a larger degree of stent recoil.