Progressive Dilation of the Left Atrium and Ventricle after Acute Myocardial Infarction Is Associated with High Mortality

Background and Objectives: The purpose of this study is to identify the prevalence of progressive dilation in patients with acute myocardial infarction (AMI) combined with heart failure (HF) and determine the prognostic significance and associated factors with a geometric change of an infarcted heart. Subjects and Methods: A total of 1310 AMI patients with HF ($63.9{\pm}12.5$ years, 70% male) between November 2005 and April 2011 underwent echocardiography at admission and one year later. Left ventricular (LV) remodeling is defined as 20% progression, and left atria (LA) remodeling is 10% compared with the initial volume index. Results: The prevalence of both LA and LV remodeling was 13.9%; LV only was 9.3%, LA only 22.8% and non-remodeling was 55.1%, respectively. In the non-remodeling group, Killip class II was more frequent (83.9%, p<0.001) whereas in other remodeling groups, Killip class III was more frequent. Initial wall motion score index, ejection fraction, maximal cardiac enzyme, high sensitive C-reactive protein, B type natriuretic peptide, and triglyceride serum levels were significantly associated with heart remodeling. All causes of death occurred in 168 cases (12.8%) during the follow-up period. Mortality was the highest in the LV and LA remodeling group (20.9%) and the lowest in the nonremodeling group (11.4%). During the period of follow-up, the cumulative survival rate was significantly lower in the groups of LA and LV remodeling than in others (log rank p=0.006). Conclusion: Total mortality was significantly increased in patients AMI with geometrically progressive LA and LV dilatation.