PLASMA OSTEOPONTIN LEVELS, BUT NOT ITS MYOCARDIAL EXPRESSION, REFLECT HEART FAILURE SEVERITY IN RECENTLY DIAGNOSED DILATED CARDIOMYOPATHY

Background and aim of the study: An extracellular matrix glycoprotein osteopontin (OPN) may be detected in elevated levels in both myocardium and plasma under various pathological conditions affecting the heart. Several studies demonstrated increased plasma OPN levels in patients with heart failure due to dilated cardiomyopathy (DCM) in the past, while other studies showed high OPN expression levels in myocardium of such patients. However, very little is known about OPN levels in both plasma and myocardium of the same individual with DCM. Therefore, we aimed to compare plasma OPN levels and levels of myocardial OPN expression in patients with recent onset dilated cardiomyopathy (Ro-DCM).
Methods: We examined plasma OPN as well as creatinine, CRP, BNP and troponin I levels in 25 patients with Ro-DCM. Furthermore, all subjects underwent transthoracic echocardiography, selective coronary angiography and endomyocardial biopsy (EMB) with the assessment of myocardial OPN expression.
Results: No significant correlation between myocardial OPN expression and clinical, biochemical or echocardiographic parameters was found. In log transformation plasma OPN levels correlated significantly with BNP levels (r = 0.46, p = 0.031), with CRP levels (r = 0.52, p = 0.015) and with early diastolic mitral annular velocity (r = -0.57, p = 0.009). Association of plasma OPN log value and NYHA was borderline (p = 0.053).

Conclusions: Plasma OPN levels reflect heart failure severity in patients with Ro-DCM. Myocardial OPN expression is not associated with either plasma OPN levels or markers of heart failure in these individuals.