Relation of inflammation and left atrial remodeling in atrial fibrillation occurring in early phase of acute myocardial infarction

Background: Inflammation is frequently associated with the development of atrial fibrillation (AF). This study was performed to investigate whether the high sensitivity C-reactive protein (hsCRP) present during acute inflammation could predict early AF and its relationship to left atrial (LA) enlargement in acute myocardial infarction (AMI). Methods and results: In 401 consecutive AMI patients, AF predictors were compared between those with and without early AF. Early AF was defined as AF developing within 24 h after AMI. In order to identify the difference in the AF predictors according to LA enlargement, patients were subgrouped according to an LA volume index (LAVI) of < 32 cm³/m² (group 1, n = 321) and ≥ 32 cm ³/m² (group 2, n = 80). Thirty-three (8.2%) patients developed early AF including 17 (5.3%) and 16 (20%) patients in groups 1 and 2, respectively. The independent predictors of AF were multivessel involvement (OR = 2.51, p = 0.03), LAVI ≥ 32 cm³/m² (OR = 2.47, p = 0.03), higher hsCRP (OR = 2.24, p = 0.05), and old age (OR = 1.06, p = 0.01) in all patients. In the subgroups divided by the LAVI, higher hsCRP was a predictor of early AF only in group 1 (OR = 4.56, p = 0.004). Conclusions: Our results suggest that multivessel involvement, enlarged LA, higher hsCRP, and old age are predictors of early AF after AMI. However, hsCRP could be strongly related to early AF only in AMI patients with less dilated LA. Crown