Abstract 12459: Hemodynamic Progression of Mitral Annular Calcification: Prevalence, Characteristics, and Clinical Implications

Abstract

Background: A recent study demonstrated that transmitral mean diastolic pressure gradient (MDPG) in patients with mitral annular calcification (MAC) is associated with increased mortality, however, the longitudinal hemodynamic progression over time in patients with MAC and its characteristics are unclear. In this study, the clinical and echocardiographic characteristics of MAC correlated with hemodynamic progression and its clinical implications were investigated. Methods: In total, 161 patients (mean age 74.7±10.5 yeas, 63 men) with MAC were identified by index transthoracic echocardiography (TTE) between January 2012 and June 2016 and performed follow-up TTE after 3 years. Stable MAC (n=146, 90.7%) was defined as a difference of transmitral mean pressure gradient (MDPG) less than 2 mmHg between initial and follow-up TTE, and progressive MAC (n=15. 9.5%) was defined as MDPG increased above 2mmHg. Results: There was no significant difference of baseline characteristics between the group with stable MAC and progressive MAC. In the group of progressive MAC compared to that of stable MAC, a proportion of moderate-to-severe MAC (66.7 vs. 28.1%, p =0.002), significant MS (26.7 vs. 8.2%, p =0.046), maximal thickness of MAC (0.7±0.5 vs. 0.5±0.3, p =0.023), and MDPG (2.8±1.7 vs. 2.2±1.5, p =0.048) were significantly higher at the index TTE ( Figure ). In the group with progressive MAC, increase in left atrial (LA) volume index and pulmonary artery systolic pressure were significant. In-5-year mortality and newly developed atrial fibrillation tended to be more common in progressive MAC group, but there was no statistical significance. Conclusions: Hemodynamic progression occurs in about 10% of patients over 3 years. Patients with progressive MAC have larger baseline MAC thickness and calcification extent, even if MDPG is less than 3 mmHg. Patients with progressive MAC are more likely to develop LA enlargement and pulmonary hypertension, which are prone to poor outcome.