['Low-grade inflammation has been associated with cardiovascular disease (CVD) and chronic heart failure (CHF). The aim of the present study was to investigate the potential usefulness of the inflammatory protein calprotectin as a biomarker in CHF.', 'Plasma calprotectin was measured in 193 CHF patients with left ventricular function <45% and in 100 healthy controls at baseline. Patients with CHF were followed for a median period of 2.6 years according to mortality.', 'The levels of plasma calprotectin were significantly increased in the CHF patients compared to the control group (P < 0.01), primarily due to elevated levels in the patients with New York Heart Association (NYHA) class III and IV. Furthermore, plasma calprotectin was a superior biomarker of high NYHA classes than other parameters reflecting CHF severity, OR 2.2 (1.1-4.3) (P = 0.019). After the follow-up period, 46 patients had died. Plasma calprotectin levels did not predict mortality in CHF patients.'] Do plasma calprotectin levels reflect disease severity in patients with chronic heart failure?