Different patterns of NT-proBNP secretion in acute coronary syndromes

Background: The wide variability of NT-proBNP levels in acute coronary syndromes could arise from sympathetic activation and glomerular impairment. The aim of the study was to investigate, in this setting, the dependence of NT-proBNP from Chromogranin A (CgA) and Cystatin C (CC) levels, respectively assessing sympathetic activation and glomerular impairment. Methods: In 132 patients, 90 ST elevation acute coronary syndrome (STE-ACS) and 42 non ST elevation acute coronary syndrome (NSTE-ACS), within 24 h from symptoms and with creatinine levels lower than 141.4 μmol/L, we measured NT-proBNP, CgA and CC levels. In 41 STE-ACS patients we evaluated the kinetic profiles of the markers. Results: From the multiple regression model, to investigate the dependence of NT-proBNP from CgA, CC levels, time from symptoms, STE-ACS/NSTE-ACS subsets, gender, adjusting for the effect of left ventricular ejection fraction and age we had evidence of: 1) interactions involving the subsets, the first with CgA levels and the second with age; 2) non linear increasing effect of the delay on NT-proBNP secretion. Conclusions: Our data showed that, in the population studied, sympathetic activation and age could affect NT-proBNP secretion yielding different secretory patterns in STE- or NSTE-ACS. Only for STE-ACS we observed higher marker secretion in older patients.