N-terminal pro-brain natriuretic peptide in the elderly with myocardial infarction.

BACKGROUND: The myocardial infarction (MI) results in the change of the levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) in blood. In addition, attention is paid to the dependence of NT-proBNP levels on the patients' age. However, the behavior of natriuretic peptide levels has not been recognized well enough in the elderly with MI treated with invasive methods.

HYPOTHESIS: The aim of the study was to estimate the effect of age on NT-proBNP levels in patients with first MI, and treated with primary percutaneous coronary intervention (PCI) with complete coronary revascularization.

METHODS: One hundred and sixty-one consecutive patients with first ST-elevation MI, and treated with primary PCI with stent implantation (occlusion in infarct-related artery was the patient's only lession) were included. Determination of NT-proBNP level and echocardiography were performed on the 4th-5th day of MI.

RESULTS: Thirty-seven patients (23%) aged>or=65 y were considered as a study group. The NT-proBNP levels were nearly 4-fold higher in older patients than in younger patients. Only systolic and diastolic dysfunction, mitral regurgitation, troponin T levels, and glomerular filtration rate (GFR) were independent risk factors of the occurrence of elevated NT-proBNP concentration above median.

CONCLUSIONS: The patients' age was not a factor independently affecting the increase of NT-proBNP level above the median in patients with first MI and treated successfully with primary PCI. Independently associated elevated levels of NT-proBNP were as follows: presence of diastolic dysfunction, mitral regurgitation, left ventricular systolic dysfunction, troponin T concentration, and GFR.