Profile of plasma N-terminal proBNP following acute myocardial infarction; correlation with left ventricular systolic dysfunction.

Abstract

The aims of this study were to describe the temporal pattern of plasma N-terminal pro-brain natriuretic peptide, to examine the optimum time of sampling and to compare plasma N-terminal pro-brain natriuretic peptide to clinical criteria in terms of identification of impaired left ventricular systolic function following acute myocardial infarction. Measurements of N-terminal pro-brain natriuretic peptide were made in 60 patients at 14-48 h, 49-72 h, 73-120 h, 121-192 h following myocardial infarction and at 6 weeks in survivors. Left ventricular wall motion index was assessed during hospitalization (WMI-1) and at 6 weeks (WMI-2). N-terminal pro-brain natriuretic peptide levels were elevated at all time points, to a greater extent in anterior compared to inferior infarction (P < 0.05). A biphasic profile of plasma concentration was observed in anterior infarction with peaks at 14-48 h and 121-192 h. This was sustained at 6 weeks. N-terminal pro- brain natriuretic peptide at 73-120 h was the best independent predictor of WMI-1 (P < 0.005). N-terminal pro-brain natriuretic peptide was higher at all times in patients who received ACE inhibitor therapy compared to those who did not (P < 0.005). N-terminal pro-brain natriuretic peptide at 73-120 h (R(2) = 17.7%, P = 0.005) and previous myocardial infarction (R(2) = 5.3%, P < 0.05) were independent predictors of poor outcome (WMI-2 < or = 1.2 or death by 6 weeks). A biphasic pattern of plasma N-terminal pro-brain natriuretic peptide is seen after anterior myocardial infarction. Plasma level is strongly correlated to wall motion index soon after and remote from acute myocardial infarction. Plasma N-terminal pro-brain natriuretic peptide measured later in hospitalization better predicts poor outcome following myocardial infarction than when it is measured in the immediate post infarction period.