Effect of size and position of self-expanding transcatheter valve on haemodynamics following valve-in-valve procedure in small surgical bioprostheses: an in vitro study.

Abstract

The valve-in-valve (ViV) procedure has become a valuable alternative for the treatment of failed surgical bioprostheses (BP) in high-risk patients. However, in small BP, the clinical outcomes have been suboptimal due to high post-procedural gradients. We aimed to examine the effect of size and position of the self-expanding transcatheter heart valve (THV) CoreValve on the haemodynamics of ViV within small BP. Sizes 23 and 26 mm of the CoreValve were implanted in sizes 19 and 21 mm of three BP models: Trifecta, Mitroflow and Epic Supra. The THV was tested in three positions -normal (manufacturer recommendation), low (4 mm below normal) and high (4 mm above normal)- using a pulse duplicator. Haemodynamics were assessed by Doppler echocardiography and flowmeter, and GOA with a high-speed camera. Higher implantation was associated with lower residual gradients (normal position: -9%, high: -25% versus low). High position was, however, associated with increased risk of regurgitation in the Mitroflow and embolisation in the Epic Supra. Using a 26 mm THV instead of a 23 mm was associated with larger EOAs in the Trifecta, smaller in the Mitroflow, and increased risk of embolisation in the Epic Supra. Supra-annular positioning of the CoreValve THV is associated with improved post-ViV haemodynamics in small surgical BP. The haemodynamic outcomes are highly dependent on the model and size of surgical BP.