Abstract 14602: Osteopontin - A New Prognostic Biomarker in Patients with Cardiac Amyloidosis
Introduction and Hypothesis: Cardiac amyloidosis (CA) is associated with an adverse prognosis. However, even when clinical information is combined with biochemical and echocardiographic parameters, risk stratification in this patient population remains difficult. Consequently there is great interest in new biomarkers that may improve prognostic assessment in CA patients. The extracellular matrix protein Osteopontin (OPN) could be an interesting candidate molecule, since it was shown to play an important role in myocardial remodelling and fibrosis. We therefore hypothesized that OPN may improve risk stratification in CA.
Methods: We included 150 patients with light chain (AL) amyloidosis. Cardiac manifestation was verified in 83 patients by myocardial biopsy, while 67 patients showed no signs of cardiac involvement. In all patients OPN plasma levels were determined by ELISA and correlated with cardiac manifestation, clinical severity, echocardiographic parameters of myocardial infiltration and prognosis.
Results: Median OPN plasma levels were significantly elevated in patients with CA compared to patients with AL amyloidosis and no signs of a cardiac involvement (673 ng/ml vs 481 ng/ml; p<0.05). Furthermore, OPN plasma level correlated with several indicators of advanced CA, such as NYHA classification, impaired left ventricular function and myocardial mass index (p<0.05 for all parameters). Thirty-six patients died during mean follow-up of 20 months. Outcome was worse in patients with OPN plasma levels above a cut-off value derived by a ROC analysis (426.8 ng/mL) as compared to patients with OPN below this value (survival probability 60% vs. 86%, logrank p<0.001). Finally, in a multivariate analysis including clinical and biochemical parameters such as NT-proBNP, cTNT, low voltage pattern, NYHA classification and myocardial mass index OPN emerged as an independent predictor of all cause mortality in our patient population.
Conclusion: In conclusion, our data show that OPN plasma level can improve risk stratification in CA. Further studies are needed for validation of OPN in an independent patient cohort and for evaluation of OPN plasma levels to monitor treatment effects on cardiac involvement.
- © 2011 by American Heart Association, Inc.