Determinants of the Mid-term Improvement or Deterioration of the Ejection Fraction in Patients with an ST-segment Elevation Myocardial Infarction.

Objective Changes in the left ventricular ejection fraction (LVEF) after an ST-segment elevation myocardial infarction (STEMI) are associated with subsequent ischemic events and mortality. This study aimed to investigate the determinants of a mid-term improvement and deterioration of LVEF in patients with STEMI. Methods We included 585 patients with STEMI who had a modified Simpson EF both at index admission and mid-term (6-12 months) follow-up. We divided the patients into the EF deterioration group (≥10% decrease in EF, n=38), the EF improvement group (≥10% increase in EF, n=127), and the unchanged EF group (<10% change in EF, n=420). Results Baseline EF was significantly associated with an EF deterioration (OR1.472 per 5.0 % increase, 95%CI:1.231-1.761, p<0.001). The hemoglobin levels were inversely associated with an EF deterioration (OR0.760 per 1.0 g/dL increase, 95%CI: 0.632-0.914, p=0.003). The peak creatine kinase levels were significantly associated with an EF deterioration (OR1.034 per 100 U/L increase, 95%CI: 1.019-1.050, p<0.001). A female sex was significantly associated with an EF improvement (OR2.118, 95%CI: 1.222-3.671, p=0.008). The pulse rate was inversely associated with an EF improvement (OR0.887 per 10 bpm increase, 95%CI: 0.791-0.995, p=0.041). Infarct-related artery with LMT-left anterior descending artery was significantly associated with an EF improvement (OR1.661, 95%CI: 1.009-2.734, p=0.046). Time interval between the Baseline EF and follow-up EF was significantly associated with an EF improvement (OR1.008, 95%CI: 1.002-1.013, p=0.006). The peak creatine kinase level (OR0.981 per 100 U/L increase, 95%CI: 0.970-0.992, p<0.001) and baseline EF (OR0.568, 95%CI: 0.500-0.645, p<0.001) was inversely associated with an EF improvement. Conclusion A higher baseline EF, lower hemoglobin levels at admission, and higher peak creatine kinase levels were associated with a mid-term deterioration of LVEF, whereas a female sex, LM-LAD as the infarct-related artery, and the time interval between baseline and follow-up EF were associated with a mid-term improvement in LVEF. Knowledge of these determinants may help to refine the post-STEMI risk stratification and therapeutic strategies.