The PROTECT pilot study: a randomized, placebo-controlled, dose-finding study of the adenosine A1 receptor antagonist rolofylline in patients with acute heart failure and renal impairment.

Background: Rolofylline, an adenosine A(1) receptor antagonist, facilitates diuresis and preserves renal function in patients with acute heart failure (AHF) with renal impairment. Although not powered around any specific hypothesis, this pilot study was designed to identify an efficacious dose while refining inclusion criteria and end points.
Methods: A total of 301 patients hospitalized for AHF with an estimated creatinine clearance of 20 to 80 mL/min and elevated natriuretic peptide levels were enrolled within 24 hours of presentation to placebo or rolofylline 10, 20, or 30 mg administered as 4-hour infusions for 3 days in addition to intravenously administered loop diuretics. Post hoc analyses for end points chosen for subsequent Phase III studies were performed.
Results: Compared with placebo, rolofylline produced trends toward greater proportions of patients with marked or moderately improved dyspnea and fewer patients with worsening heart failure or renal function. Serum creatinine increased in patients receiving placebo and remained stable or tended to decrease in those receiving rolofylline. On day 14 the absolute differences between placebo and rolofylline for change in creatinine increased with increasing rolofylline dose, reflecting the lesser increase in creatinine in rolofylline-treated patients (r = -0.12, P = .030). Treatment with 30 mg, the dose selected for the pivotal trials, was associated with a trend toward reduced 60-day mortality or readmission for cardiovascular or renal cause (hazard ratio, 0.55; 95% confidence interval, 0.28-1.04).
Conclusion: These results demonstrate that adenosine A(1) receptor blockade with rolofylline can prevent renal impairment in patients with AHF and may positively affect acute symptoms and 60-day outcome. A 2000-patient trial of this agent is now under way.