Usefulness of serum myeloperoxidase in prediction of mortality in patients with severe heart failure

Background: Myeloperoxidase levels were shown to reflect endothelial dysfunction, inflammation, atherosclerosis and oxidative stress. Objectives: To examine the role of circulating myeloperoxidase, a leukocyte-derived enzyme, as a predictor of mortality in patients with congestive heart failure. Methods: Baseline serum MPO levels were measured in 285 consecutive CHF patients and 35 healthy volunteers. N-terminal pro-brain natriuretic peptide and high sensitivity C-reactive protein concentrations were also measured. The primary outcome endpoint was overall mortality. Results: MPO levels were significantly elevated in patients with CHF compared to healthy volunteers (P = 0.01). During a mean follow-uup of 40.99 ± 11.3 months there were 106 deaths. On a univariate Cox regression analysis MPO levels were of marginal value (P = 0.07) whereas NT-proBNP was of considerable value (P < 0.0001) in predicting all-cause mortality. By dividing our cohort according to NT-proBNP levels into high, intermediate and low risk groups a clear difference in mortality was shown. By further dividing the patient cohort according to MPO levels above or below the median (122.5 ng/ml), mortality prediction improved in the patients with intermediate NT-proBNP values. Conclusions: MPO levels are elevated in CHF and correlate with disease severity. MPO has an additive predictive value on mortality in patients with intermediate NT-proBNP levels.