Transcatheter bicuspid versus tricuspid aortic valve replacement in patients with a small aortic annulus: an observational study

Abstract

Objective: To compare the clinical outcomes and haemodynamic performance following transcatheter aortic valve replacement (TAVR) in patients with severe bicuspid versus tricuspid aortic stenosis (AS) and small annuli.

Design: Retrospective analysis based on a prospective observational cohort.

Setting: Single-centre registry of patients undergoing TAVR between 2016 and 2023.

Participants: A total of 427 patients (193 bicuspid (BAV) and 234 tricuspid (TAV) aortic valve) with symptomatic severe AS and small annuli (median area 381.5 mm² (IQR 348.0-406.4)), all undergoing preprocedural multidetector CT and standardised follow-up echocardiography.

Main outcomes measure: Baseline characteristics, technical success, procedural complications, haemodynamic performance and bioprosthetic-valve dysfunction (BVD) were compared between groups. The primary clinical outcome was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause mortality, stroke and rehospitalisation for heart failure.Cox regression was used to adjust for confounders.

Results: Compared with TAV patients, BAV recipients experienced higher technical failure rates (11.4% vs 6.0%, p=0.045) but lower permanent pacemaker implantation (4.7% vs 12%, p=0.008) at discharge. The 1-year MACCE rate was similar between groups (14.5% vs 9.8%, log-rank p=0.719), and Cox regression analyses adjusting for confounders revealed no significant difference (HR 1.408 (95% CI 0.622 to 3.191), p=0.412). Both groups demonstrated significant improvements in valve haemodynamics, with comparable rates of BVD (11.4% vs 9.2%, p=0.502) and structural valve dysfunction. Multivariate analysis demonstrated equivalent long-term survivals (HR 0.950 (95% CI 0.526 to 1.714), p=0.864) between groups.

Conclusion: TAVR provides comparable clinical and haemodynamic outcomes for bicuspid and tricuspid AS with a small aortic annulus, despite greater procedural complexity in BAV cases. These findings support cautious expansion of TAVR to select BAV patients when performed with meticulous procedural planning.

Keywords: Aortic Valve Stenosis; Heart Valve Diseases; Transcatheter Aortic Valve Replacement.

Figure 1. Procedural outcomes between TAV versus BAV. (A) VARC-3 technical success between TAV and BAV with small annulus; (B) VARC-3 device success between TAV and BAV. ns indicates p values >0.05; *p values ≤0.05; **p values ≤0.01; ***p values ≤0.001. BAV, bicuspid aortic valve; TAV, tricuspid aortic valve; VARC-3, Valve Academic Research Consortium-3.

Figure 2. Echocardiographic outcomes between TAV versus BAV. (A) Aortic valve mean gradient and aortic valve area for the TAV and BAV at baseline and at different time points after valve implantation. (B) PPM severity for the TAV and BAV at baseline and at different time points after valve implantation. (C) Total aortic regurgitation for the TAV and BAV at baseline and at different time points after valve implantation. (D) Paravalvular regurgitation for the TAV and BAV at baseline and at different time points after valve implantation. ns indicates p values >0.05; *p values ≤0.05; **p values ≤0.01; ***p values ≤0.001. AVA, aortic valve area; BAV, bicuspid aortic valve; mPG, mean pressure gradient; PPM, prosthesis-patient mismatch; TAV, tricuspid aortic valve.

Figure 3. One-year primary clinical outcome and bioprosthetic-valve dysfunction between TAV versus BAV. (A) Kaplan-Meier curve of MACCEs; (B) bioprosthetic-valve dysfunction through 1 year for the TAV and BAV; (C) structural valve dysfunction through 1 year for the TAV and BAV. ns indicates p values >0.05; *p values ≤0.05; **p values ≤0.01; ***p values ≤0.001. BAV, bicuspid aortic valve; MACCEs, major adverse cardiac and cerebrovascular events; TAV, tricuspid aortic valve.

Figure 4. Subgroup analysis. All percentages are the cumulative incidences of the MACCEs through 1 year in the two groups stratified by specific subgroup variables. The p value is from the test statistic for testing the interaction between the BAV and TAV groups and any subgroup variable. BAV, bicuspid aortic valve; NYHA, New York Heart Association; PPM, prosthesis-patient mismatch; STS PROM, Society of Thoracic Surgeons Predicted Risk of Mortality; TAV, tricuspid aortic valve.