Contrast-enhanced computed tomography for quantifying mitral annular calcification in mitral valve surgery and association with outcomes

Aims Evaluation of mitral annular calcification (MAC) on non-contrast computed tomography (CT) has been associated with clinical outcomes. There is no accepted methodology for evaluating MAC using contrast CT. This study aimed to validate MAC quantification using contrast CT and evaluate its clinical impact in patients undergoing mitral valve (MV) surgery. Methods and results Between 2011 and 2020, 303 patients with native MV dysfunction who underwent contrast CT prior to surgery were included. In a validation cohort of 50 patients undergoing both contrast and non-contrast CT, Agatston scores were correlated to derive contrast-specific thresholds. Baseline clinical parameters and a multi-parametric MAC score (range: 2–12) were recorded for the entire cohort. The contrast-enhanced CT MAC score consisted of Agatston score (1 point: <650 AU; 2 points: 650–1700AU; 3 points: 1700–2800 AU; 4 points: >2800 AU), MAC circumferential angle (1 point: <90°; 2 points: 90–<180°; 3 points: 180–<270°; 4 points: 270–360°), trigone involvement (1 point: single trigone; 2 points: both trigones), myocardial infiltration (1 point), and left ventricular outflow tract involvement (1 point). Associations between MAC score and clinical outcomes were evaluated. Higher MAC scores predicted increased total operating time (P < 0.001), cross-clamp time (P < 0.001), intensive care unit stay (P < 0.001), open surgical approach (P < 0.001), in-hospital complications (P < 0.001), and pacemaker implantation (P = 0.055). Contrast-enhanced CT MAC score independently predicted all-cause mortality (P < 0.001). Conclusion A multiparametric MAC score on contrast CT enables assessment of MAC severity, and is associated with operative approach and postoperative outcomes in patients with MV dysfunction undergoing surgery.