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

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.

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.

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).

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.