Determinants of Improvement of Mid-term Ejection Fraction in Patients with Acute Myocardial Infarction.

Persistent severe left ventricular (LV) systolic dysfunction after acute myocardial infarction (AMI) is associated with increased morbidity and mortality, whereas mid-term recovery of LV systolic function after AMI is associated with better long-term outcomes. The purpose of this study was to investigate the determinants of mid-term improvement of LV ejection fraction (EF) in AMI patients. We included 210 AMI patients who had modified Simpson EF both at the index admission and mid-term follow up. The difference of EF between the index admission and mid-term follow-up was calculated in all study patients. The EF improvement group was defined as mid-term ≥ 10% EF increase compared with the index admission EF. Of 210 AMI patients, 46 (21.9%) were allocated to the EF improvement group and 164 (78.1%) to the non-EF improvement group. Brain natriuretic peptide (BNP) at the timing of admission was significantly greater in the EF improvement group (735.8 ± 1077.6 pg/mL) than in the non-EF improvement group (239.0 ± 419.8 pg/mL) (P < 0.001). Multivariate logistic regression analysis revealed that log10 BNP at the timing of admission (OR 3.36, 95% CI 1.69-6.66, P < 0.001) and left main trunk-left anterior descending artery (LM-LAD) as the infarct-related artery (OR 3.34, 95% CI 1.59-7.02, P = 0.001) were significantly associated with EF improvement. In conclusion, elevated BNP at the timing of admission and LM-LAD as the infarct-related artery were significantly associated with mid-term LVEF recovery. Our results support aggressive acute treatment for those severe AMI, because the possibility of mid-term LVEF recovery is greater compared with other AMI.