New 29-mm balloon-expandable prosthesis for transcatheter aortic valve implantation in large annuli.

Background: An important number of patients are considered unsuitable for transcatheter aortic valve implantation because of a large native aortic valve. A new 29-mm balloon-expandable transcatheter valve offers the option to gain a maximal effective orifice area without paravalvular leakage. This study sought to define ranges of safe applicability in terms of device landing zone geometry. A second purpose was to determine performance of the prosthesis and clinical outcome.

Methods: Between April 2011 and July 2012, the new 29-mm SAPIEN XT prosthesis was implanted by means of transapical access in 78 patients with large aortic annuli. The study group represents 32.9% of all transapical transcatheter aortic valve implantations performed at our institution during the observation period; 82 patients receiving 26-mm prosthesis served as a control group. Device landing zone morphology was analyzed by echocardiography and computed tomography.

Results: The postimplant effective orifice area (study versus control group) was 2.7 cm(2) (interquartile range, 2.3 to 3.0 cm(2)) and 2.1 cm(2) (interquartile range, 1.7 to 2.4 cm(2)), respectively (p < 0.001), without any severe patient-prosthesis mismatch. Postprocedural regurgitation was similar in both groups (p = 0.892): absent in 56 (71.8%) and 54 (65.9%) patients, trace or mild in 21 (26.9%) and 27 (32.9%), and moderate in 1 (1.3%) and 1 (1.2%), respectively. Including patients in cardiogenic shock, the overall 30-day mortality rate of the study and control groups was 5.1% and 1.2%, respectively. One-year survival was 76.7% ± 8.6% with no difference from control patients (p = 0.743).

Conclusions: The new 29-mm balloon-expandable prosthesis broadens the indication for transcatheter aortic valve implantation to include patients with large annuli. The outcome is very favorable.