Granulocyte elastase in acute myocardial infarction.

Plasma concentrations of polymorphonuclear granulocytes elastase (PMN elastase) in complex with alpha-1 proteinase inhibitor are a marker of neutrophil activation. The latter complex, creatine kinase and cardiac troponin T, were measured in peripheral venous blood samples serially drawn in 39 patients with acute myocardial infarction. Of the total, 29 received intravenous thrombolytic therapy either with streptokinase (n = 15), urokinase (n = 7) or recombinant tissue type plasminogen activator (n = 7). Creatine kinase activities and cardiac troponin T concentrations were used as markers of myocardial tissue injury. In all patients with acute myocardial infarction, PMN elastase was elevated (median 80 micrograms/l, interquartile range 71 to 100 micrograms/l). Peak and cumulative (area under curve) concentrations of PMN elastase did not correlate closely with determinants of myocardial injury (r < 0.2, n.s.). PMN elastase increased during the first 6 h after starting thrombolytic therapy, whereas it decreased in conventionally treated patients and 12 h later increased. Maximum concentrations of PMN elastase, however, were not significantly higher in patients with thrombolytic therapy than in those without. In acute myocardial infarction patients with complications such as cardiac arrest with subsequent resuscitation (n = 5), cardiac rupture (n = 1) or cardiogenic shock (n = 2), PMN elastase plasma concentrations were significantly higher (p = 0.04) than in uncomplicated infarctions. In the complicated patients, changes in elastase concentrations paralleled or even preceded changes in the clinical presentation. Therefore, thrombolytic treatment seems not to significantly influence the amount of systemic neutrophil activation, but plasma PMN elastase could be a useful marker to monitor and identify complications in acute myocardial infarction.