Serial changes in plasma brain natriuretic peptide concentration at the infarct and non-infarct sites in patients with left ventricular remodelling after myocardial infarction

Abstract

Objectives: To clarify the role of infarct and non-infarct sites on left ventricular (LV) remodelling after myocardial infarction by measuring brain natriuretic peptide (BNP) from each site.

Methods and results: BNP from the aorta and the anterior interventricular vein (AIV) was measured in 45 patients with first anterior myocardial infarction at one, six, and 18 months. The LV was significantly dilated (> 10 ml/m(2) of end diastolic volume from one to 18 months) in 20 patients (remodelling (R) group) but not in 25 others (non-remodelling (NR) group). Patient characteristics and LV functions did not differ significantly at one month but plasma BNP concentration was higher in group R than in group NR (336 (288) v 116 (106) pg/ml, p < 0.01), predicting the degree of LV dilatation. The difference in BNP concentration between the aortic root and AIV (DeltaBNP), reflecting BNP secreted from the infarct site, did not differ at one month. In both groups BNP and DeltaBNP significantly decreased from one to six months (p < 0.05) and decreased from six months to 18 months, but the change was not significant. BNP and DeltaBNP were significantly higher in group R than in group NR after six months, when LV dilatation was not evident in both groups.

Conclusion: Enhanced BNP secretion at one month in the non-infarct and infarct ventricular sites predicts subsequent LV dilatation (that is, remodelling). The slower process of LV remodelling decreased BNP secretion at both sites. Thus, BNP concentration should be useful for monitoring ventricular remodelling after infarction.

Figure 1

Plasma brain natriuretic peptide (BNP) concentration at the aortic root shown at 1, 6, and 18 months after the onset of myocardial infarction. *p < 0.05 within group differences between 1 month and 6 or 18 months; †p < 0.05 remodelling (R) group versus non-remodelling (NR) group at 1 month (two way analysis of variance).

Figure 2

Difference in plasma BNP concentration between the aortic root and the anterior intraventricular vein (ΔBNP) shown at 1, 6, and 18 months after the onset of myocardial infarction. *p < 0.05 within group differences between 1 month and 6 or 18 months (two way analysis of variance).

Figure 3

Changes in BNP remodelling index, expressed as BNP/end diastolic volume index (EDVI). *p < 0.05 within group differences between 1 month and 6 or 18 months; †p < 0.05 R group versus NR group at 1 month (two way analysis of variance).