The Association of Plasma Apelin Levels with Plaque Vulnerability

OBJECTIVES: Apelin is a recently discovered peptide that is expressed in many tissues particularly in the cardiovascular system and exerts several actions, most of which are vasodilatory and positive inotropic effects. Based on this, an apelin deficiency is believed to play a significant role in the development of hypertension and heart failure. However, the association of apelin with the pathogenesis of atherosclerosis and especially plaque vulnerability remains unestablished. Thus, to contribute to the literature, in this study, we sought to determine the association of apelin concerning plaque vulnerability in the setting of the acute coronary syndrome. METHODS: In this study, we prospectively enrolled a total of 80 patients; 40 with acute coronary syndrome and 40 patients with stable chronic ischemic heart disease. Plasma apelin levels were measured in all patients along with other routine biochemical parameters, and all patients underwent a transthoracic echocardiographic examination. RESULTS: Plasma apelin levels were significantly lower in patients with the acute coronary syndrome (221.2±66.7 vs 254.3±77.9 p=0.04). However, there was no correlation between plasma apelin levels and serum inflammatory markers or coronary artery disease severity. CONCLUSION: Low plasma apelin levels may create a tendency towards vulnerable plaque and acute coronary syndrome.