Objective: To compare the acute hemodynamic effects and safety of intravenous injection of recombinant human brain natriuretic peptide (rhBNP) versus intravenous nitroglycerin (NIT) in acute myocardial infarction (AMI) patients with heart failure.
Methods: On top of standard therapy, 42 consecutive patients who suffered from anterior wall AMI with heart failure [pulmonary capillary wedge pressure (PCWP) > 16 mm Hg] within 12 to 24 hours from the onset of chest pain were randomized into rhBNP group (n = 21, 1.5 microg/kg bolus intravenous injection followed by 0.0075 microg.kg(-1).mn(-1) for the first 3 hours and 0.015-0.03 microg.kg(-1).mn(-1) infusion for following 21 hours) and NIT group (n = 21, 10 to 100 microg/mn intravenous infusion for 24 hours). The hemodynamic parameters were monitored by Swan-Ganz catheter at baseline, during drug infusion and 6 hours post infusion withdraw; total urine output was also obtained. The major adverse cardiac events (MACE) were observed up to 1 week after drug infusions.
Results: Central venous pressure and systolic blood pressure remained unchanged after rhBNP or NIT infusion. Compared to baseline level, PCWP was significantly reduced by 48.9% (P < 0.01) at 30 minutes after rhBNP infusion and this effect remained up to 6 hours post infusion withdraw; PCWP reduced by 28.7% (P < 0.05) at 2 hours after NIT infusion and this effect remained to 6 hours before infusion withdraw. Cardiac index (CI) was increased by 27.1% (P < 0.05) at 1 hour after rhBNP infusion and remained till 6 hours post infusion withdraw; CI was significantly increased at 3 hour after NIT infusion and this effect disappeared after infusion withdraw. The PCWP and CI values were significantly higher in rhBNP group than that of NIT group at 30 minutes and 2 hours (P < 0.05). Heart rate was significantly reduced at 30 minutes (95.3 +/- 7.4 vs. 118.0 +/- 8.2 bpm, P < 0.05) and at 2 hour (92.8 +/- 6.8 vs. 109.2 +/- 7.6 bpm, P < 0.05) in rhBNP and NIT group, respectively and heart rate remained reduced during the whole infusion period in both groups. The total urine output for 30 hours in rhBNP group (1870 +/- 535 ml) tended to be higher than that in NIT group (1538 +/- 620 ml, P > 0.05). There was no symptomatic hypotension or other adverse events during drug infusion in both groups and MACE up to 1 week post drug infusion was also similar between the two groups.
Conclusion: Intravenous injection of rhBNP results in more rapid and long-lasting hemodynamic improvements than that of NIT in AMI patients with heart failure and it is also feasible and safe for clinic use in AMI patients with heart failure.