Aortic shape and diameter variations are predictive of short-term complications in transcatheter aortic valve replacement.

Introduction: Anatomic and geometric considerations are critical components for transcatheter aortic valve replacement (TAVR) procedural planning. Aortic root geometry and 3-dimensional orientation have been previously associated with short-term complications but with mixed and inconsistent results. The purpose of this study was to investigate aortic 3-dimensional anatomical shape variants identified by principal component analysis (PCA) and whether these variants are associated with short-term complications.

Methods: Pre-TAVR planning chest CT angiograms (N = 100) were analyzed to create 3-dimensional anatomic aortic models were subjected to PCA. Aortic shape variants described by principal components (PCs) and their respective scores were calculated for each patient in addition to standard planning geometric parameters. A short-term composite complication outcome within 1-month from the implantation included major and minor stroke, life-threatening and major bleeding, stage 3 acute kidney injury, new heart block and moderate plus paravalvular leak (PVL).

Results: A total of 25 patients (25%) experienced perioperative complications following TAVR. Shape based PCs were: PC1 - variation in aortic arch height, isthmic angle, and aortic arch angle; PC2 aortic length; PC3- aortic tilt. Diameter based PCs described: PC1- diameter size along the entire aortic length; PC2- aortic diameter tapering, PC3- ascending to arch diameter ratio. On univariable logistic regression, four variables were predictive of periprocedural complications, including the ascending aortic diameter at the level of Valsalva sinuses (OR: 0.88 (95%CI: 0.78-1.00), P = 0.044), PC1-shape scores (OR: 1.01 (95%CI: 1.00-1.02), P = 0.011), PC2-shape scores (OR: 0.98 (95%CI: 0.97-1.00), P = 0.034), and PC-1 diameter scores (OR: 0.98 (95%CI: 0.96-1.00), P = 0.023). An optimized multivariable model considering only PC1-shape and PC1-diameter revealed a C-statistic of 0.76 with a sensitivity of 92.0% and specificity of 32.0%.

Conclusion: Aortic shape variants combining increased aortic arch height, acute isthmic angle, and mild aortic arch angle as identified by PCA were associated along with aortic size with higher rates of periprocedural complications in patients undergoing transfemoral TAVR. PCA identified shape variations outperformed standard 2-dimensional geometric measurements and could be considered as part of risk stratification prior to TAVR planning.