Prosthesis-patient mismatch in high-risk patients with severe aortic stenosis: A randomized trial of a self-expanding prosthesis

OBJECTIVES: We compared the incidence of prosthesis-patient mismatch (PPM) between transcatheter aortic valve replacement (TAVR) using a self-expanding bioprosthesis and surgical aortic valve replacement (SAVR) in the CoreValve US High Risk Pivotal Trial. We sought to determine the influence of PPM on clinical outcomes.

METHODS: Patients with severe aortic stenosis and at increased risk for surgery were randomized 1:1 to TAVR or SAVR. Postoperative PPM was defined by the effective orifice area index (EOAi) as severe PPM (EOAi ≤ 0.65 cm(2)/m(2)) and no severe PPM (EOAi > 0.65 cm(2)/m(2)); clinical outcomes were analyzed in the TAVR arm (n = 389) and SAVR arm (n = 353). Left ventricular mass index and regression were analyzed at baseline and 1 year.

RESULTS: The incidence of severe PPM in the SAVR group at 1 year was 25.7% versus 6.2% in the TAVR group (P < .0001). Left ventricular mass index regression at 1 year was 6.8% for TAVR and 15.1% for SAVR in patients with severe PPM. At 1 year the rate of all-cause mortality and acute kidney injury were significantly greater in all patients (TAVR + SAVR) with severe PPM compared with no severe PPM (20.6% vs 12.0% [P = .0145] for death and 19.2% vs 8.5% [P = .0008] for acute kidney injury).

CONCLUSIONS: In patients with high surgical risk and severe aortic stenosis, severe PPM is more common in patients treated with SAVR than those treated with TAVR. Patients with severe PPM are a greater risk for death and acute kidney injury than patients without severe PPM.