Effects of intravenous nesiritide on human coronary vasomotor regulation and myocardial oxygen uptake

Background - Nesiritide, recombinant human B-type natriuretic peptide, has been shown to be efficacious in the treatment of decompensated heart failure. The effects of intravenous nesiritide on the human coronary vasculature have not been studied. Methods and Results - Ten patients underwent right and left heart catheterization. Baseline coronary blood flow was determined using quantitative coronary angiography (QCA) and an intracoronary Doppler-tipped guidewire. Myocardial oxygen uptake was measured using a coronary sinus catheter. Patients then received an intravenous infusion of nesiritide (2 mug/kg bolus followed by 0.01 mug/kg per min infusion) for 30 minutes. Right atrial pressure decreased 52% (P = 0.012), pulmonary artery mean pressure decreased 19% (P = 0.03), pulmonary capillary wedge pressure decreased 46% (P = 0.002), and mean arterial pressure decreased 11% (P = 0.007). QCA demonstrated a 15% increase in coronary artery diameter from a baseline of 2.6 +/- 0.8 to 3.0 +/- 0.8 mm at 30 minutes (P = 0.007). The coronary velocity measure of average peak velocity increased 14% from 20.8 +/- 6.4 at baseline to 23.8 +/- 7.2 cm/s at 5 minutes (P = 0.015) and then returned to baseline for the remainder of the infusion. Coronary blood flow increased 35% (P = 0.007), whereas coronary resistance decreased 23% at 15 and 30 minutes (P = 0.036). Myocardial oxygen uptake decreased 8% during the nesiritide infusion ( P = 0.043). Conclusions - Nesiritide exerts coronary vasodilator effects on both the coronary conductance and resistance arteries. Despite a decrease in coronary perfusion pressure, coronary artery blood flow is increased, coronary resistance is decreased, and myocardial oxygen uptake is decreased.