Extensive calcification of the mitral valve annulus in transcatheter aortic valve implants

Abstract

Objectives: This study sought to report the calcification pattern of the mitral valve annulus and its implications for procedural and safety outcomes in transcatheter aortic valve implantation.

Methods: Between November 2018 and September 2019, a total of 305 patients had transcatheter aortic valve implants at our institution. The extent of calcification of the mitral valve annulus was analysed, and the impact on safety outcomes was evaluated.

Results: The prevalence of mitral annular calcification (MAC) was 43%. Calcification of the mitral valve annulus was either less than or at least one-third of the posterior annulus (34% and 32%), the whole posterior annulus (28%) or the extension to the attachment of the anterior leaflets (7%). Severe circumferential MAC revealed moderate paravalvular leaks in 5/8 (63%) patients and was associated with right branch bundle block [odds ratio (OR) 2.01 (0.39-3.06); P = 0.098] and low cardiac output [OR 3.12 (1.39-7.04); P = 0.033]. Subannular calcification at the anterolateral trigonum represented a risk factor for left ventricular outflow tract injury [OR 3.54 (1.38-8.27); P = 0.001] in balloon-expandable valves, associated with relevant rhythm disorders [OR 2.26 (1.17-5.65); P = 0.014] and female gender (7/8, 88%). The 30-day all-cause mortality in circumferential MAC reaching into the anterior annulus (grade IV) compared to patients with less MAC (grade I-III) was 13% vs 2% with a mean valve size of 24.6 vs 25.7 mm.

Conclusions: Extensive MAC was associated with moderate paravalvular leaks, with implications for the prosthesis size and survival in transcatheter aortic valve implants. In severe MAC, we recommend implanting oversized self-expandable prostheses, the goal being to reduce the risk of right branch bundle block and paravalvular leaks.

Subj collection: 122, 125.

Keywords: Calcification pathology; Mitral valve annulus; Transcatheter aortic valve implantation.