Renal effects of ularitide in patients with decompensated heart failure.

BACKGROUND: Renal function frequently deteriorates in decompensated heart failure (DHF) patients, and one determinant is reduced renal blood flow. This may, in part, result from low cardiac output (CO), reduced mean arterial pressure (MAP), and venous congestion. The combined impact of both venous congestion (elevated right atrial pressure [RAP]) and low MAP are reflected by a reduced pressure gradient MAP-RAP. This study investigated the renal effects of ularitide, a synthetic version of the renal natriuretic peptide urodilatin in DHF patients. METHODS: In SIRIUS II, a double-blind phase II trial, 221 patients hospitalized for DHF (with dyspnea at rest or minimal activity, cardiac index or=18 mm Hg) were randomized to a single 24-hour infusion of ularitide (7.5, 15, or 30 ng/kg per minute) or placebo added to standard therapy. RESULTS: Estimated glomerular filtration rate, serum creatinine, creatinine clearance, and blood urea nitrogen (BUN) were not impaired by ularitide throughout infusion and during a 2-day follow-up period. At 24 hours, 15 ng/kg per minute ularitide reduced BUN levels (-4.07 +/- 12.30 vs -0.20 +/- 7.50 for placebo, P < .05). Ularitide at 15 and 30 ng/kg per minute rapidly elevated CO with sustained effects. Although 15 ng/kg per minute ularitide preserved the pressure gradient MAP-RAP, 30 ng/kg per minute ularitide reduced MAP-RAP by -7.8 +/- 10.6 mm Hg vs -2.4 +/- 9.8 mm Hg for placebo (P < .01, at 6 hours). A strong inverse correlation between MAP-RAP and BUN levels (Corr = -0.50579, P = .00015) was observed with 15 ng/kg per minute ularitide. CONCLUSIONS: Single 24-hour infusions of ularitide at 15 ng/kg per minute preserved short-term renal function in DHF patients possibly by both elevating CO and maintaining the MAP-RAP pressure gradient.

Haemodynamic and clinical effects of ularitide in decompensated heart failure.

AIMS: Ularitide is a synthetic form of urodilatin, a natriuretic peptide produced in the kidney with vasodilating, natriuretic, and diuretic effects, that offers promise for the management of decompensated heart failure (DHF). We assessed the efficacy and safety of ularitide in treating patients with DHF. METHODS AND RESULTS: In this Phase II randomized, double-blind, placebo-controlled trial, 221 DHF patients received either placebo (n=53) or ularitide at 7.5 ng/kg/min (n=60), 15 ng/kg/min (n=53), or 30 ng/kg/min (n=55) as a 24-h continuous infusion. At 6 h, ularitide demonstrated a significant decrease in pulmonary capillary wedge pressure (P=0.052, P=0.000004, P=0.000002, respectively) and improved dyspnoea score in the 7.5, 15, and 30 ng/kg/min ularitide group (P=0.0026, P=0.0026, P=0.0013, respectively). Ularitide reduced systemic vascular resistance and increased cardiac index for the 15 and 30 ng/kg/min groups (P=0.017, P=0.00002, respectively). Systolic blood pressure (BP) decreased dose dependency. Heart rate and serum creatinine were unchanged through day 3. Most frequently reported drug-related adverse events through day 3 in all ularitide groups were dose-dependent BP decrease and hypotension. CONCLUSION: Ularitide lowered cardiac filling pressures and improved dyspnoea without apparent early deleterious effects on renal function in DHF patients. These results suggest that ularitide may play a role in the management of DHF.