Transcatheter or Surgical Aortic Valve Replacement in Patients with Severe Aortic Stenosis and Small Aortic Annulus: A Randomized Clinical Trial

Abstract

Background: The optimal treatment in patients with severe aortic stenosis (AS) and small aortic annulus (SAA) remains to be determined. The objectives of this study were to compare the hemodynamic and clinical outcomes between transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) in patients with a SAA. Methods: Prospective multicenter international randomized trial performed in 15 university hospitals. Participants were 151 patients with severe AS and SAA (mean diameter <23 mm) were randomized (1:1) to TAVR (n=77) vs SAVR (n=74), The primary outcome was impaired valve hemodynamics (i.e. severe prosthesis patient mismatch [PPM ] or moderate-severe aortic regurgitation [AR]) at 60 days as evaluated by Doppler-echocardiography and analyzed in a central echocardiography core laboratory. Clinical events were secondary outcomes. Results: The mean age of the participants was 75±5 years, with 140 (93%) women, a median STS of 2.50 (1.67-3.28)%, and a median annulus diameter of 21.1 (IQR: 20.4-22.0) mm. There were no differences between groups in the rate of severe PPM or moderate-severe AR (severe PPM (TAVR: 4 [5.6 %], SAVR: 7 [10.3%], p=0.30), and moderate-severe AR (none in both groups). There were no differences between groups regarding mortality (TAVR: 1 [1.3%], SAVR: 1 [1.4%], p=1.00) and stroke (TAVR:0, SAVR: 2 [2.7%], p=0.24) at 30 days. After a median follow-up of 2 (1-4) years, there were no differences between groups regarding mortality (TAVR: 7 [9.1%], SAVR: 6 [8.1%], p=0.89), stroke (TAVR: 3 [3.9%], SAVR: 3 [4.1%], p=0.95), and cardiac hospitalization (TAVR: 15 [19.5%], SAVR: 15 [ 20.3%], p=0.80). Conclusions: In patients with severe AS and SAA (women in the vast majority), there was no evidence of superiority of contemporary TAVR vs. SAVR regarding valve hemodynamic results. After a median follow-up of 2 years, there were no differences in clinical outcomes between groups. These findings suggest that the 2 therapies represent a valid alternative for treating patients with SA and SAA, and treatment selection should likely be individualized according to baseline characteristics, additional anatomical risk factors, and patient preference. However, the results of this study should be interpreted with caution due to the limited sample size leading to an underpowered study, and need to be confirmed in future larger studies.