Does frame geometry play a role in aortic regurgitation after Medtronic CoreValve implantation?

Aortic regurgitation (AR) after Medtronic CoreValve System (MCS) implantation may be explained by patient-, operator- and procedure-related factors. We sought to explore if frame geometry, as a result of a specific device-host interaction, contributes to AR.

Using rotational angiography with dedicated motion compensation, we assessed valve frame geometry in 84 patients who underwent TAVI with the MCS. Aortic regurgitation was assessed by angiography (n=84, Sellers) and echocardiography at discharge (n=72, VARC-2). Twenty-two patients (26%) had AR grade ≥2 using contrast angiography, and 17 (24%) by echocardiography. Balloon predilatation and sizing and depth of implantation did not differ between the two groups. Despite more frequent balloon post-dilatation in patients with AR (40.9 vs. 9.7%, p=0.001), the frame was more elliptical at its nadir relative to the patient's annulus (6±13 vs. -1±11%, p=0.046) and occurred in a larger proportion of patients (61.9 vs. 26.8%, p=0.004). Although the Agatston score and the eccentricity of the MCS frame relative to the annulus were independent determinants of AR (odds ratio: 1.635 [1.151-2.324], p=0.006, and 4.204 [1.237-14.290], p=0.021), there was a weak association between the Agatston score and the adjusted eccentricity (Spearman's rank correlation coefficient =-0.24, p=0.046).

These findings indicate that AR can be explained by a specific device-host interaction which can only partially be explained by the calcium load of the aortic root.