Abstract 18273: Mitral Annular Calcification is Associated With Higher Operative Risks and Worse Survival in Hypertrophic Cardiomyopathy

Abstract

Background: Mitral annular calcification (MAC) is common in hypertrophic cardiomyopathy (HCM), usually accompanied by mitral leaflet calcification, subvalvular apparatus calcification, and mitral valve dysfunction. However, the impact of MAC on surgical strategy and clinical outcomes in HCM is not fully understood. Methods: This cohort enrolled 1035 consecutively recruited patients diagnosed with HCM between January 2016 and December 2021. All patients received a computed tomographic scan prior to surgery. Results: Of the 1035 patients, 112 (10.8%) had MAC, including 39 patients with moderate or severe MAC (calcification area greater than one-third of the annulus). Patients with MAC were significantly older (59.6±8.2 years vs. 47.5±12.3 years, p<0.001) and more likely to be female (61.8% vs. 35.4%, p<0.001). Echocardiography showed a higher proportion of mitral leaflet thickening (17.9% vs. 6.0%, p<0.001) in patients with MAC. Moreover, patients with MAC had a higher rate of annular reconstruction (1.79% vs 0.11%, p=0.002), plastic ring implantation (5.36% vs 1.84%, p=0.017), chordae release (12.50% vs 5.09%, p=0.002), artificial neochordoplasty (2.68% vs 0.54%, p=0.015), and fibrous membrane removal (8.93% vs 4.12%, p=0.022), as well as longer ventilation time [19 hours, interquartile range (IQR) 17.0-26.0 vs. 18 hours, IQR 14.0-20.5, p<0.001], intensive care unit stay [61 hours, IQR 36.5-96.0 hours vs. 48 hours IQR 24.0-72.0 hours, p<0.001] and postoperative hospital stay [8days, IQR 7-11 days vs. 7 days, IQR 6-8 days, p<0.001]. During a median follow-up time of 26.2 months (IQR, 17.0 to 39.5 months), 5 death and 158 major adverse cardiovascular events (MACE) were observed. Kaplan-Meier survival curves showed that patients with MAC had a higher cumulative rate of all-cause mortality (p=0.026) and MACE (p=0.003) compared to their counterparts. On multivariable Cox regression analysis, moderate or severe MAC was an independent risk factor for MACE (Hazard ratio =2.38, 95% confidence interval: 1.31-4.32). Conclusions: The prevalence of MAC was 10.8% in this study. The presence of MAC was associated with a higher rate of concomitant operations, longer hospital stays, and worse survival.