Abstract 2566: Elevated Myeloperoxidase Levels in Patients with Severely Impaired Left Ventricular Function
Background. Activation of polymorphonuclear neutrophils and intraluminal release of the heme enzyme myeloperoxidase (MPO) has emerged as a critical prognostic indicator in unstable coronary disease and MPO-derived oxidants have been firmly linked to impaired LV function in rodent models of heart failure. Whether MPO levels are also elevated in patients with LV dysfunction however remains elusive. Here we assessed plasma levels of myeloperoxidase (MPO) in chronic heart failure patients.
Methods and results. 447 consecutive patients (age: 59.9±14.3 y, 152 females (34.0%)) underwent evaluation of LV function using transthoracic echocardiography and MPO plasma levels were determined by ELISA. Impaired left ventricular function was defined as an ejection function <30%. Blood samples were taken in all patients in order to assess MPO plasma levels. In 53 patients with impaired left ventricular function (idiopathic cardiomyopathy: n=24; ischemic cardiomyopathy: n=29) MPO plasma levels were significantly elevated, which was irrespective of the etiology of heart failure (78.76±126.20 vs. 34.23±39.22 ng/ml; p<0.01). MPO plasma levels predicted impaired left ventricular function independently of age, gender, traditional risk factors, renal function, cholesterol and CRP. The calculated ROC-curve for MPO revealed an area under the curve of 0.649 (confidence interval: 0.580 – 0.717; p<0.01).
Conclusion. MPO plasma levels serve as powerful independent predictors of LV dysfunction in patients with both ischemic and dilated cardiomyopathy and suggest systemic neutrophil activation to represent a so far underrecognized event in this disease.