Neutrophil activation precedes myocardial injury in patients with acute myocardial infarction.

Myeloperoxidase (MPO), a heme protein abundantly expressed and secreted by polymorphonuclear neutrophils (PMN), has emerged as a critical mediator in coronary atherosclerosis. Retrospective analyses have suggested that free plasma levels of MPO predict adverse outcome in patients with low troponin T (TnT) levels who subsequently experience myocardial injury. The aim of this study was to evaluate the time course of MPO plasma levels in the early stages of acute myocardial infarction (AMI).