Mitral annular calcifications (MAC) is a common finding in elder patients referred for transcatheter aortic valve implantation (TAVI), sometimes responsible of significant degenerative calcified mitral stenosis (CaMS), but prevalence of both is poorly defined. Multidectector computed tomography (MDCT) allows fine quantification of calcifications and is a reliable tool in rheumatic mitral stenosis, but its contribution in CaMS remains unknown. Our objective was to estimate prevalence of MAC and CaMS in patients referred for TAVI using MDCT, and determine morphological factors leading from MAC to CaMS.

A cohort of 346 consecutive patients referred for TAVI evaluation was screened by MDCT for MAC. One hundred and seventy four patients were positive for MAC. Among these patients, 165 patients had mitral valve area (MVA) assessable by MDCT planimetry (mean age 84 years). Analysis by segment revealed calcifications on: A1 30.9%, A2 29.1%, A3 42.4%, P1 56.4%, P2 78.8%, P3 69.7%. Mean mitral calcification volume and MVA were 1020±1398mm3 and 246±90mm ², respectively. CaMS were severe, moderate and mild in 2.4%, 21.8% and 9.7% patients, respectively. Correlation between mitral calcification volume and MVA was significant but moderate (r=–0.433). On multivariate analysis, MVA was independently linked to mitral calcification volume, aortic annular area and specific patterns of mitral leaflet calcification underlining the role of A2 (AUC 0.81). Interobserver reproducibility of MVA was high (ICC 0.935).

MDCT allows detailed assessment of MAC in TAVI populations, demonstrating high prevalence, and quantification of CaMS with high reproducibility. Mitral analysis should become routine during MDCT screening before TAVI as it may significantly alter the therapeutic strategy.