Mitral annular calcification on routine Non-ECG Gated Chest CT Is associated with advanced atrioventricular block requiring permanent pacing: A case-control study

The purpose of this study was to determine whether visual or quantitative mitral annular calcification (MAC) burden on routine non-contrast, non-ECG-gated chest computed tomography (CT) is associated with permanent pacemaker (PPM) implantation for advanced atrioventricular (AV) block. MAC has been linked to conduction disturbances after transcatheter aortic valve implantation (TAVI). Whether MAC visible on routine chest CT is associated with significant AV conduction disease in non-TAVI patients remains uncertain. In this retrospective single-center case-control study, 39 consecutive patients who underwent PPM implantation for symptomatic advanced AV block and had non-contrast chest CT were compared with 39 age- and sex-matched controls without AV block or prior PPM. MAC was graded visually by annular circumference involvement and quantified using an Agatston-based score. Visual MAC was more prevalent in the PPM (+) group than in the PPM (-) group (22 of 39 [56%] vs. 12 of 39 [31%]; P = 0.039). The prevalence of PPM implantation increased across visual MAC categories, from 39% with no MAC and 48% with MAC involving < 1/3 of the annular circumference to 80% with MAC involving 1/3 to 1/2 and 100% with MAC involving > 1/2 of the annular circumference (P = 0.007). Quantitative MAC categories also differed (44%, 33%, and 78% PPM implantation for MAC scores of 0, 1 to 400, and > 400, respectively; P = 0.022). In multivariable analysis, MAC score > 400 remained independently associated with PPM implantation (odds ratio: 24.6; 95% confidence interval: 1.63 to 370.96; P = 0.02).Visual and quantitative MAC burden on routine non-contrast chest CT were associated with PPM implantation for advanced AV block. Structured assessment and reporting of marked MAC may provide a clinically useful marker in patients with suspected AV conduction disease.