No clinical effect of prosthesis-patient mismatch after transcatheter versus surgical aortic valve replacement in intermediate- and low-risk patients with severe aortic valve stenosis at mid-term follow-up: an analysis from the NOTION trial

Abstract

Objectives: Prosthesis-patient mismatch (PPM) after surgical aortic valve replacement (SAVR) for severe aortic valve stenosis (AVS) is common, but less common after transcatheter aortic valve replacement (TAVR) in patients considered at high risk for death after surgery. The objectives of this study were to determine incidence and clinical effect of PPM after SAVR and TAVR in a primarily low-risk patient group.

Methods: Patients 70 years or older with severe isolated AVS, regardless of predicted operative mortality risk, were consecutively randomized 1:1 to TAVR using a self-expandable bioprosthesis (n = 145) or SAVR (n = 135). Post-procedure PPM was graded after 3 months as follows: Not present-mild, if indexed effective orifice area (iEOA) >0.85 cm²/m², moderate, if 0.65 cm²/m² < iEOA ≤ 0.85 cm²/m² and severe, if iEOA ≤0.65 cm²/m². Outcomes were major adverse cardiac and cerebrovascular events (MACCE, e.g. composite rate of all-cause death, stroke, myocardial infarction or valve reintervention), cardiac-related hospitalizations and New York Heart Association (NYHA) functional class after 2 years.

Results: The incidence and the severity of PPM were significantly lower after TAVR compared with SAVR (severe, moderate, none-mild 14.0, 35.5, 50.4 vs 33.9, 36.7, 29.4%; P<0.001). PPM resulted in similar higher mean valve gradients at 3 months for both groups. Baseline characteristics related to severe PPM were younger age, absence of diabetes mellitus, lower mortality-risk score for TAVR, and younger age and higher body mass index for SAVR. At 2 years, there were numerical but no statistically significant differences between both TAVR and SAVR patients with severe and no severe PPM for MACCE (0.0 vs 12.8% for TAVR; P = 0.13, and 13.5 vs 7.0% for SAVR; P = 0.27), number of cardiac-related hospitalizations (mean ± standard deviation 0.4 ± 0.6 vs 0.6 ± 0.8; P = 0.23, and 0.4 ± 0.8 vs 0.5 ± 0.9; P = 0.70) and NYHA functional class (Class I/II/III/IV: 64.7/29.4/5.9/0.0 vs 62.1/34.7/3.2/0.0%, respectively; P = 0.91, and 71.4/25.7/2.9/0.0 vs 72.9/22.9/4.3/0.0%, respectively; P = 0.92).

Conclusions: The incidence of PPM was lower and less severe after TAVR compared with SAVR in intermediate- and low-risk patients with severe AVS. There were no significant differences in MACCE, cardiac-related hospitalizations or NYHA class after 2 years for patients with versus those without severe PPM.

Keywords: Aortic valve stenosis; Clinical outcomes; Heart valve prosthesis; Prosthesis-patient mismatch.