Transcatheter Aortic Valve Replacement in Patients With a Small Annulus - From the Japanese Nationwide Registry (J-TVT).

BACKGROUND The details and consequences of a small aortic annulus among transcatheter aortic valve replacement (TAVR) patients remain uncertain. This study investigated the short-term outcomes in patients with small annular size and compared the 30-day outcome between intra- and supra-annular devices, with similar outer casing diameter in this subgroup.Methods and Results:Cases registered in the Japanese national TAVR registry between August 2013 and December 2017 were analyzed. Among a total of 5,870 registered patients, 647 (11.0%) had small annulus (area ≤314 mm2) measured by multi-detector computed tomography. Patients with a small annulus had a significantly smaller indexed effective orifice area (iEOA, 1.10 cm2/m2[0.92-1.35] vs. 1.16 cm2/m2[0.96-1.39], P<0.001) and higher mean pressure gradient (mPG, 10.0 mmHg [6.9-14.2] vs. 8.5 mmHg [6.0-11.5], P<0.001) compared with a normal-sized annulus. Among patients with a small annulus, those receiving a 20 mm intra-annular device had a smaller iEOA (0.94 cm2/m2[0.78-1.06] vs. 1.07 cm2/m2[0.8-1.24], P=0.001) and higher mPG (14.0 mmHg [10.0-18.5] vs. 11.0 [7.0-14.0], P<0.001) compared with those receiving a 23-mm supra-annular device, although the incidence of paravalvular leakage (≥moderate) was similar (14.4% vs. 16.5%, P=0.69). CONCLUSIONS Patients with a small annulus were associated with less hemodynamic improvement. A supra-annular device is associated with better echocardiographic improvement in patients with a small annulus, without increasing paravalvular leakage.