Temporal trends of frame expansion and paravalvular leak reduction after transcatheter aortic valve replacement with self-expandable prostheses

Background: Paravalvular leakage (PVL) is a common finding after transcatheter aortic valve replacement (TAVR) and affects late clinical outcome. It is more frequent with self-expandable (SE) transcatheter-heart-valve (THV). Few is known about SE-THV expansion after implantation. The purpose is to assess SE-THV frame expansion and its possible influence on PVL. Methods: We designed a prospective pilot study to assess the time-course of SE-THV frame dimensions and PVL after TAVR. Consecutive patients undergoing TAVR with SE-THV were enrolled. Prosthesis fluoroscopy and echocardiography were prospectively performed immediately after TAVR (T0) and before discharge (T1) to grade PVL. Prosthesis diameters were assessed in 2 fluoroscopic orthogonal views. PVL reduction ≥1+ from T0 to T1 at echocardiography was the primary study endpoint. Results: Twenty-five patients were enrolled. Mean interval between T0 and T1 evaluations was 5 days. Grade 1 or 2 was present in 76% of patients at T0 and in 68% at T1 (P=0.034). A total of 7 patients (28%) improved PVL ≥1 grade from T0 to T1. Differences between T0 and T1 fluoroscopic diameters were not statistically significant. When comparing the diameter changes according to PVL evolution, patients with PVL improvement (as compared with those without) had significantly larger minimum diameter increase at both annulus/inflow (P=0.016) and outflow/distal edge (P=0.027). Conclusions: PVL may improve in the early days after SE-THV and those patients with PVL improvement may have THV frame expansion. Further studies are needed to confirm such preliminary observations and to establish the clinical relevance of this phenomenon.