PARTNER Analysis Shows Major Impact of Aortic Annulus Size on Hemodynamics and Outcomes for TAVR and Surgical Valve Replacement

September 30, 2014—Josep Rodés-Cabau, MD, et al published findings from a study that sought to evaluate the effects of aortic annulus size on valve hemodynamics and clinical outcomes in those patients included in the PARTNER (Placement of Aortic Transcatheter Valves) randomized controlled trial cohort A and the nonrandomized continued-access cohort. The study is available online ahead of print in Circulation: Cardiovascular Interventions.

The PARTNER trial is an evaluation of the Edwards Sapien transcatheter heart valve (Edwards Lifesciences) for the treatment of severe aortic stenosis, which supported US Food and Drug Administration approval of the device for transcatheter aortic valve replacement (TAVR).

As summarized in Circulation: Cardiovascular Interventions, patients included in the randomized controlled trial (n = 574) and nonrandomized continued access (n = 1,358) cohorts were divided in tertiles according to aortic annulus diameter (small aortic annulus tertile, medium aortic annulus tertile, and large aortic annulus tertile, respectively) as measured by transthoracic echocardiography. Severe prosthesis-patient mismatch was defined as an effective aortic orifice area of < 0.65 cm²/m².

In the randomized controlled trial cohort, patients in the small aortic annulus tertile who underwent TAVR had a lower incidence of severe prosthesis-patient mismatch (19.7% vs 37.5%; P = .03) and only a trend toward a higher incidence of moderate-to-severe paravalvular leaks compared with surgical aortic valve replacement (5.7% vs 0%; P = .06).

In the large aortic annulus tertile, there were no differences in the rate of prosthesis-patient mismatch between groups, and a significant increase in moderate-to-severe paravalvular leaks was associated with TAVR (9% vs 0%; P = .01). There were no differences in mortality between TAVR and surgical aortic valve replacement.

In the nonrandomized continued access cohort, there were no differences in prosthesis-patient mismatch between the small aortic annulus and large aortic annulus tertiles, but a higher rate of moderate-to-severe paravalvular leaks was observed in the large aortic annulus tertile (5.9% vs 11.5%; P = .009). Patients in the large aortic annulus tertile had a higher mortality rate at 1-year follow-up (P = .02), and differences persisted in multivariable analysis (P = .048 for large aortic annulus tertile vs medium aortic annulus tertile; P = .035 for large aortic annulus tertile vs small aortic annulus tertile).

The investigators concluded that aortic annulus size had a major impact on valve hemodynamics and clinical outcomes after TAVR and surgical aortic valve replacement. They advised that this study highlights the importance of considering aortic annulus size in the evaluation of high-risk patients who are candidates for aortic valve replacement.