[The examination of clinical prognostic importance of atrial and brain natriuretic peptide in patients with acute myocardial infarction]

Abstract

Natriuretic peptides ANP, BNP and CNP with their receptors A, B, and C play an important role in maintaining the homeostasis. They have vasodilating, diuretic and natriuretic actions and regulate the systemic resistance. These peptides have been proved to contribute in pathogenesis of many diseases, for example heart failure, hypertension, acute coronary events or hepatic and renal insufficiency. The aim of our study was the estimation whether ANP or BNP could be markers of postinfarct heart failure in patients after thrombolytic therapy. The survey was made in 96 patients with acute myocardial infarction (AMI), who were treated in Department of Cardiology of University School of Medicine in Wrocław. Patients were divided into 2 groups. The first group consisted of 56 patients with reperfusion after thrombolytic therapy and the second group created 40 patients without reperfusion. All patients were administered acethylsalicylic acid, 100 mg r-tPA (recombined tissue plasminogen activator) i.v. within 90 min and heparin in typical doses for the first 3-5 days. Venous blood samples for ANP and BNP estimation were taken before thrombolysis and then in 1st, 3rd, 5th and 30th day after treatment. We also measured the ejection fraction and activity of CPK and CK-MB in all the patients. Patients stayed under clinical observation for 12 months. Our study showed that the levels of ANP and BNP increase in 1st day after treatment in all patients with AMI. The normalization of ANP and BNP occurs in 3rd day after treatment in patients with reperfusion and in patients without reperfusion there are increased levels of these peptides even in 30th day. The increased level of BNP (> 160 pg/ml) is a significant risk factor of left ventricle systolic dysfunction, renewed AMI and sudden death in all patients with AMI after thrombolytic therapy whereas the increased level of ANP (> 100 pg/ml)--only in patients without reperfusion. Taking BNP as a marker of postinfarct heart failure it is possible to asses the risk of this complication in first day after thrombolytic therapy and choose the most proper treatment.