Micro-dislodgement of a self-expanding transcatheter heart valve: Incidence, predictors, and outcomes

Objectives: Malpositioning of transcatheter heart valves increases the risk of procedural failure. For the ACURATE system, inadvertent movement of the prosthesis to a varying extent is sometimes observed upon full release, but the incidence, mechanisms, and clinical impact of such valve micro-dislodgement (VMD) are poorly understood. The aim of the present study was to assess the incidence, predictors, and clinical outcomes of VMD in an all-comers population that underwent transcatheter aortic valve implantation (TAVI) with the ACURATE neo2 prosthesis (NEO2).

Methods: This was a retrospective analysis of 448 consecutive patients who underwent transfemoral TAVI with NEO2 at our institution. VMD was defined as displacement ≥2 mm between the initial position and immediately after valve release as measured on fluoroscopy at the non-coronary cusp. The initial valve position prior to step 2 was categorized using the radiopaque marker band (RMB) relative to the annular plane. In addition, further anatomical and procedural characteristics were assessed.

Results: A total of 68 (15.2%) cases with VMD were identified. A larger cover index, higher RMB position, partial detachment of the lower crown, and severe parallax prior to deployment were independent predictors of VMD, whereas a position of the delivery system in the outer curvature was protective against VMD. Among patients with VMD, the rates of valvular malpositioning and thus technical failure (VARC-3) were higher, but mean transprosthetic gradients were lower.

Conclusions: VMD occurs in a notable proportion of transfemoral TAVI cases with NEO2 and is associated with more frequent technical failure of the procedure.