Study to Assess the Safety and Tolerability of IV Tonapofylline in Subjects With Acute Decompensated Heart Failure (ADHF) and Renal Insufficiency

Inclusion Criteria: * Previous diagnosis of heart failure. * Must have ADHF, requiring hospitalization, with clinical evidence for volume overload Exclusion Criteria: * History of an allergic reaction to any xanthine-containing substance. * History of seizure * History of stroke * Myocardial infarction * Uncorrected hemodynamically significant primary valvular disease or known Obstructive or restrictive cardiomyopathy. * Serious systemic infection * Major surgical procedures within 30 days * Acute coronary syndrome * Cardiogenic shock * Baseline body weight \>150 kg * Participation in any other investigational study of drugs or devices within 30 days prior to Screening * Nursing mothers, pregnant women, or women planning on becoming pregnant during the study * Presence of any clinically significant condition that might interfere with optimal safe participation in this study