Clinical Significance of Circumferential Mitral Annular Calcification in Mitral Valve Replacement

Abstract

Objective: Mitral valve surgery in the presence of mitral annular calcification (MAC) is a technical challenge. We aimed to evaluate the clinical significance of circumferential MAC in patients who underwent mitral valve replacement (MVR). Methods: 387 patients (61.3±12.5 years) who underwent MVR between 2003 and 2020 were enrolled; mitral regurgitation (n=168), stenosis (n=127), and steno-insufficiency (n=92). The preoperative computed tomography was reviewed to evaluate the presence and distribution of MAC. Patients were divided into two groups by distribution of MAC; circumferential MAC (CMAC) group (n=36) vs none-or-trivial MAC (NMAC) group (n=351). Cox regression was used to evaluate the influence of CMAC on overall death and MACCE. Results: Cardiopulmonary bypass time was significantly longer in CMAC group (176±69 min) than in NMAC group (149±54 min), P=0.005. The operative mortality was significantly higher in CMAC group; CMAC group (7/36, 19%) vs NMAC group (15/351, 4%), P=0.002. The overall survival and freedom from MACCE were significantly worse in CMAC group (log-rank P=0.011 and 0.009, respectively). In multivariable analysis, age, smoking, chronic kidney disease, left ventricular dysfunction and rheumatic valve disease were independent predictors of overall deaths and MACCE. Adjusting for these independent predictors, CMAC was associated with increased risk of MACCE (P=0.045, hazard ratio [HR] 1.96, 95% confidence interval [CI] 1.02-3.78), but CMAC was not an independent predictor of overall death (P=0.166, HR 1.68, 95% CI 0.81-3.51). Conclusions: Circumferential MAC was associated with higher early mortality and increased risk of MACCE after MVR. Further study to address circumferential MAC during MVR should be performed.