Three-Year Outcomes of Balloon-Expandable Transcatheter Aortic Valve Implantation According to Annular Size

Data on the association between annular size and transcatheter aortic valve implantation (TAVI) outcomes beyond 1 year are limited. The present study assessed the association between the aortic annulus size and TAVI clinical and hemodynamic outcomes at 3 years of follow-up. Patients were classified according to the aortic annulus size as having small, intermediate, and large annuli (size <400, 400 to 574, and ≥575 mm, respectively). The co-primary endpoints were all-cause mortality and heart failure hospitalization. Further, the changes in hemodynamic outcomes over the follow-up period (median 37, interquartile range: 26 to 45 months) were assessed. The present analysis included 850 patients, with 182 patients (21.4%), 538 patients (63.3%), and 130 patients (15.3%) in the small, intermediate, and large-sized aortic annulus groups, respectively. The groups had comparable age and pre-TAVI pressure gradients; however, patients with small annuli had higher Society of Thoracic Surgeons risk scores. Adjusted Cox regression analysis showed that compared to patients with intermediate-sized annuli, patients with small and large annuli had similar all-cause mortality (hazard ratio [HR] = 1.11, 95% confidence interval [CI] 0.72 to 1.69 and HR = 0.74, 95% CI 0.48 to 1.16, respectively) and heart failure hospitalization rates (HR = 0.96, 95% CI 0.55 to 1.69 and HR = 1.26, 95% CI 0.73 to 2.17, respectively). However, patients with small annuli had consistently higher mean and peak pressure gradients and a higher risk of patient-prosthesis mismatch. The risks of moderate-to-severe regurgitation and structural valve deterioration were similar between the three groups. In conclusion, although patients with small annuli had higher transvalvular gradients, there was no significant association between the aortic annulus size and TAVI clinical outcomes at 3 years of follow-up. Future studies should compare the performance of transcatheter valve types in patients with different aortic annulus sizes.