Transcatheter aortic valve implantation in patients with an extremely small native aortic annulus: The OCEAN-TAVI registry

Abstract

Background: Transcatheter aortic valve implantation (TAVI) has been reported to be advantageous over surgical aortic valve replacement owing to the low incidence of prosthesis-patient mismatch (PPM) and large effective orifice area (EOA). However, data on TAVI for extremely small annuli are limited. The present study aimed to compare post-procedural hemodynamics and morphology between 20-mm and 23-mm Sapien XT (SXT) transcatheter heart valves (THVs) with extremely small annuli (<314mm²).

Methods: All patients with severe aortic stenosis treated with TAVI at eight Japanese centers between October 2013 and January 2016 were prospectively included in the Optimized CathEter vAlvular iNtervention (OCEAN-TAVI) registry. In the overall cohort of 20-mm (19 patients) and 23-mm SXTs (492 patients) with extremely small annuli, the patient groups were matched one-to-one using propensity scores, and post-procedural echocardiography and multidetector computed tomography data were compared for 18 matched patients from each group (matched cohort).

Results: In the matched cohort, the mean gradient was higher (15.4±4.1 vs. 12.2±4.8mmHg, p=0.04), EOA was lower (1.22±0.25 vs. 1.44±0.37cm², p=0.02) and THV area was lower (245.6±19.1 vs. 298.5±33.3mm², p<0.01) in the 20-mm group than in the 23-mm group. However, all patients in both groups were asymptomatic. Although moderate PPM was more prevalent in the 20-mm group than in the 23-mm group (31.6% vs. 7.9%, p<0.01), the incidence of severe PPM was low and similar between the groups (0% vs. 0.4%, p=1.00) in the overall cohort.

Conclusion: A 20-mm SXT in patients who require a small bioprosthesis leads to favorable short-term outcomes.

Keywords: Aortic stenosis; Prosthesis-patient mismatch; Small annulus; Transcatheter aortic valve implantation.