Abstract 12383: Large Field-of-View Intravascular Ultrasound for Peri-Procedural Assessment of Stent Frame Expansion After Transcatheter Heart Valve-in-Valve

Abstract

Introduction. It is unknown whether large field-of-view intravascular ultrasound (IVUS) can be a valid peri-procedural imaging tool to assess actual expansion of transcatheter heart valve (THV) during valve-in-valve procedures. Hypothesis. To compare % expansion of SAPIEN 3 THV measured with peri-procedural IVUS versus post-procedural cardiac gated contrast multi-slice computer tomography (MSCT). Expansion was defined as actual outer frame area/nominal area x 100%. Methods. Studied were patients with successful valve-in-valve for failed surgical mitral and tricuspid bioprosthetic valves. All underwent peri-procedural IVUS using 10MHz Vision PV035 (Philips North America Corporation, Andover, USA) and post-procedural MSCT (SOMATOM Definition Flash, Dual Source, SIEMENS). IVUS and MSCT (Syngo Via, Siemens, Germany) measurements were off -line and done at 1-mm step along the entire height of SAPIEN 3 THV (height 18, 20 and 22 mm for the Sapien THV 23, 26 and 29 mm, respectively). Results. Five patients (68.8±11.2 years, 3 female) were treated for failed surgical mitral (n=3) and tricuspid (2) bioprosthetic valves using SAPIEN 3 THV size 23mm (n=1), 26mm (n=1), and 29mm (n=3). Mean peri-procedural and pre-discharge residual transvalvular gradient differed substantially (1.9±0.9 vs 7.9±1.1mmHg, p=0.001). In total, 104 corresponding cross-sections of the THVs were measured with both IVUS and MSCT. Actual outer-frame SAPIEN 3 expansion was smaller within the lengths of inflow and mid segment (overlapping the ring) than in the outflow, being substantially smaller than nominal (Fig 1). Overall, there was very good agreement between % expansion of THV stent frame assessed in IVUS and MSCT (93.5%±13.3% vs 96.3%±11.3%; r =0.976 and p<0.001). Conclusions. Peri-procedural use of large field-of-view IVUS offers an accurate insight into actual THV expansion deployed valve-in-valve. Figure 1. % expansion of SAPIEN 3 measured in IVUS and MSCT.