Comparison of Catheterization Versus Echocardiographic-Based Gradients in Balloon-Expandable Versus Self-Expanding Transcatheter Aortic Valve Implantation.

Abstract

In patients with transcatheter aortic valve implantation (TAVI), accurate assessment of gradients is important to assess valve function and durability, which drives clinical decision-making. We sought to evaluate discrepancies in aortic valve mean gradients with balloon-expandable and self-expanding TAVI. We retrospectively reviewed 507 patients that underwent TAVI and compared mean gradients by catheterization to transthoracic Doppler echocardiography. Mean gradients by Doppler in balloon-expandable (11.0 ± 5.8 mm Hg) and self-expanding devices (8.7 ± 4.5 mm Hg) were significantly higher than catheterization (3.2 ± 4.0 mm Hg vs 3.5 ± 4.1 mm Hg, respectively; P<.001). In a subgroup analysis of skirted valves, Doppler gradients in balloon-expandable (9.8 ± 4.4 mm Hg) and self-expanding devices (8.6 ± 5.1 mm Hg) were significantly higher than catheterization (3.5 ± 4.1 mm Hg vs 4.2 ± 4.8 mm Hg, respectively; P<.001). When the effect of valve size on gradients was analyzed, Doppler gradients were significantly higher than catheterization for all comparisons. When indexed for valve size, patients with large aortas who received a balloon-expandable TAVI had greater pressure differential than those who received a self-expanding TAVI (8.24 ± 0.46 mm Hg vs 5.16 ± 0.66 mm Hg; P<.001). This trend was not seen in patients with a small aorta-to-valve index. Following TAVI, aortic valve mean gradients acquired by Doppler were higher than catheterization and the discrepancy was more pronounced in balloon-expandable than self-expanding prostheses. These differences persist in skirted valves and across valve sizes. These observations may reflect periprocedural hemodynamic changes, differences between prosthetic flow acceleration, and/or pressure recovery.