Abstract 6169: Osteopontin Plasma Level Independently Predict Right Ventricular Dysfunction in Patients with Pulmonary Arterial Hypertension
The extracellular matrix protein Osteopontin (OPN) was found upregulated in several models of cardiac failure and appears to play an important role in myocardial remodeling. Moreover, our group recently showed that OPN plasma level are not only elevated in patients with left sided heart failure, but also correlated with an adverse prognosis. Since right ventricular dysfunction is an important predictor of morbidity and mortality in patients with pulmonary arterial hypertension (PAH), we now assessed the diagnostic power of OPN in this patient cohort. We included 85 patients with PAH of different etiology in this study, while 43 healthy individuals of similar age and sex distribution served as controls. OPN plasma level were determined by ELISA and assessed for correlation with clinical severity, right ventricular dysfunction and established biomarkers, including NT-pro-BNP. Median OPN was significantly elevated in patients with pulmonary arterial hypertension compared to healthy controls (720 ng/ml vs. 382 ng/ml; p<0.0001). Furthermore, median OPN level were higher in patients with moderate to severe heart failure compared to patients with no or mild symptoms (WHO Fc III/IV 866 ng/ml vs. WHO Fc I/II 686 ng/ml; p=0.03). Patients with a right ventricular enddiastolic diameter above 30mm displayed higher median OPN plasma level (789 ng/ml vs. 512 ng/ml; p<0.001). Additionally, plasma level of OPN above the median (766 ng/ml) reliably predicted right ventricular dysfunction in our patient cohort (OR 6.0; 95%-CI 2.0 –18.4; p=0.001). In a multivariate analysis including demographical, clinical and biochemical parameters such as NT-pro-BNP, OPN emerged also as an independent predictor of right ventricular dysfunction (OR 5.3; 95%-CI 1.1–27.1; p=0.04). In summary, the data of the current study show for the first time that plasma level of OPN are elevated in patients with PAH. Therefore, the novel biomarker OPN might improve the non invasive monitoring of right ventricular dysfunction and remodelling in patients with PAH.