Ascending aorta and pure aortic regurgitation transcatheter aortic valve replacement: insights from the National Transcatheter Valve Therapeutics Registry.

BACKGROUND: Data regarding the association between self-expandable transfemoral transcatheter aortic valve replacement (TF-TAVR) and pure native aortic regurgitation (PNAR) are limited. The authors described their initial experience with self-expandable TF-TAVR for the treatment of patients with PNAR from the NTCVR database in China. METHODS: This was a national registry-based, multicentre, retrospective cohort study. Patients with PNAR were enrolled from the NTCVR in China between January 2017 and December 2023. The primary endpoint event was all-cause mortality at 30 days. Logistic regression analysis and machine learning techniques were used to identify the risk factors associated with 30-day all-cause mortality of TF-TAVR in patients with PNAR. RESULTS: Total 890 patients with PNAR (mean age 73.2 years; 56.3% men) from 72 centres in China were enrolled in this study. The in-hospital and 30-day all-cause mortality were 2.0% and 2.7%, respectively. By multivariate logistic regression analysis, the diameter of the ascending aorta (OR, 1.103 (95% CI 1.005 to 1.212); p=0.039) and renal insufficiency (OR, 4.602 (95% CI 1.455 to 14.553); p=0.009) were associated with the 30-day all-cause mortality. Moreover, Shapley Additive explanations analysis for the machine learning model XGBoost also highlighted the diameter of the ascending aorta as the key predictor; patients with an ascending aorta greater than 41.6 mm had a significantly higher 30-day all-cause mortality rate (OR, 5.027 (95% CI 2.042 to 12.696); p=0.0004). Moreover, the NYHA class III/IV and annulus long diameter were predictors of technical success in multivariate analysis. CONCLUSION: In this large national registry-based observational and exploratory study, we identified the ascending aorta as the key predictor for PNAR patients who underwent self-expandable TF-TAVR. Patients with ascending aortic diameters greater than 41.6 mm may have a significantly higher 30-day all-cause mortality rate.