Apelin in ST segment elevation and non-ST segment elevation acute coronary syndromes: a novel finding

Apelin is a novel endogenous peptide with inotropic and vasodilatory properties. To investigate the role of apelin in the prognosis of acute coronary syndromes (ACS) and to assess the relationship between apelin and other diagnostic and prognostic markers. Seventy-six patients with ACS (mean age 62.1 ± 10 years) were evaluated in terms of their plasma apelin-36 concentrations, ejection fraction (EF), high sensitivity C-reactive protein (hsCRP), creatine kinase (CK), CK-MB and troponin I levels. The study group consisted of 35 ST elevation myocardial infarction (STEMI) and 41 non-ST elevation (NSTE) ACS patients. Patients were followed up for one year for cardiovascular outcomes. There was no significant relationship between apelin and TIMI, GRACE, GENSINI scores, hsCRP and EF in STEMI and NSTE-ACS groups (p > 0.05). Apelin showed positive correlations with CK, CK-MB and troponin I in patients with NSTE-ACS, but a negative correlation in patients with STEMI (p < 0.05). There were no statistically significant differences between patients reaching the composite end point at one year with regard to apelin levels. Apelin was positively correlated with cardiac biomarkers in patients with NSTE-ACS but negatively correlated in patients with STEMI. In STEMI, generally larger amounts of myocardial cells are subjected to infarction compared to NSTE-ACS, which may explain why apelin levels decrease with increasing CK, CK-MB and troponin levels in STEMI patients.