B-type natriuretic peptide infusions in acute myocardial infarction.

BACKGROUND

Natriuretic peptides have actions likely to ameliorate cardiac dysfunction. B-type natriuretic peptide (BNP) is indicated as treatment for decompensated cardiac failure.

OBJECTIVE

To determine the utility of BNP in acute myocardial infarction (MI).

DESIGN

Double-blind randomised placebo-controlled trial.

SETTING

Tertiary hospital coronary care unit.

PATIENTS

28 patients with acute MI with delayed or failed reperfusion and moderate left ventricular dysfunction.

INTERVENTIONS

Infusion of BNP or placebo for 60 hours after MI.

MAIN OUTCOME MEASURES

Neurohormonal activation and renal function in response to BNP infusion, secondary end points of echocardiographic measures of left ventricular function and dimension.

RESULTS

BNP infusion resulted in a significant rise in BNP (276 pg/l vs 86 pg/l, p = 0.001). NT-proBNP levels were suppressed by BNP infusion (p = 0.002). Atrial natriuretic peptide (ANP) and NT-proANP levels fell with a significant difference in the pattern between BNP infusion and placebo during the first 5 days (p<0.005). C-type natriuretic peptide (CNP) and NT-proCNP levels rose during the infusion with higher levels than placebo at all measurements during the first 3 days (p<0.01). Cyclic guanosine monophosphate (cGMP) was raised during the infusion period showing a peak of 23 pmol/l on day 2 (placebo 8.9 pmol/l, p = 0.002), with a correlation between BNP and cGMP levels (p<0.001). Glomerular filtration rate (GFR) fell with BNP infusion but was not significantly lower than with placebo (71.0 (5.6) vs 75.8 (5.4) ml/min/1.73 m2, p = 0.62). Patients receiving nesiritide exhibited favourable trends in left ventricular remodelling.

CONCLUSIONS

Nesiritide, given soon after MI, induced increments in plasma cGMP and CNP and decrements in other endogenous cardiac peptides with a neutral effect on renal function and a trend towards favourable ventricular remodelling.