Background: The optimal treatment in patients with severe aortic stenosis and small aortic annulus (SAA) remains to be determined. This study aimed 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: This prospective multicenter international randomized trial was performed in 15 university hospitals. Participants were 151 patients with severe aortic stenosis and SAA (mean diameter <23 mm) randomized (1:1) to TAVR (n=77) versus SAVR (n=74). The primary outcome was impaired valve hemodynamics (ie, severe prosthesis patient mismatch or moderate-severe aortic regurgitation) 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±5.1 years, with 140 (93%) women, a median Society of Thoracic Surgeons predicted risk of mortality of 2.50% (interquartile range, 1.67%-3.28%), and a median annulus diameter of 21.1 mm (interquartile range, 20.4-22.0 mm). There were no differences between groups in the rate of severe prosthesis patient mismatch (TAVR, 4 [5.6%]; SAVR, 7 [10.3%]; P=0.30) and moderate-severe aortic regurgitation (none in both groups). No differences were found between groups in mortality rate (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 (interquartile range, 1-4) years, there were no differences between groups in mortality rate (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 aortic stenosis and SAA (women in the majority), there was no evidence of superiority of contemporary TAVR versus SAVR in 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 severe aortic stenosis 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 because of the limited sample size leading to an underpowered study, and need to be confirmed in future larger studies.
Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03383445.
Keywords: aortic stenosis; prosthesis-patient mismatch; transcatheter aortic valve implantation.