The management of patients with congestive heart failure (CHF) can place a significant economic burden on managed care organizations, leading providers to seek treatments that are cost-effective. Diuretics play a significant role in the treatment of edema associated with CHF. We evaluated the use of 2 loop diuretics, torsemide and furosemide, in patients with CHF in a managed care setting. This prospective study compared clinical, economic, and quality-of-life outcomes in 240 patients randomized to the 2 drugs. Patients with New York Heart Association (NYHA) class II or class III CHF requiring loop diuretic treatment, either alone or in conjunction with other therapy, were eligible. Patients were told about the study during an office visit, and those with an interest in participating and who met the eligibility criteria were given further information and the opportunity to participate. After investigators obtained informed consent, patients were enrolled, randomized to either treatment, and followed for 6 months. Outcomes included CHF/cardiovascular (CV)-related medical costs, change in NYHA class, change in sodium retention score, hospitalizations, physician visits, medication use, adverse events, and change in quality of life. A total of 103 patients were randomized to torsemide, and 137 patients were randomized to furosemide. Except for body weight, patient demographic characteristics did not differ between groups at baseline; patients in the torsemide group were significantly heavier (P = 0.004). The results showed that mean total CHF/CV-related medical costs did not differ between groups (torsemide, $1520.07; furosemide, $1503.26; P = 0.975), despite higher mean drug-acquisition costs for torsemide patients ($121.01 vs $42.95; P < 0.0001). Mean costs were similar for CHF/CV-related hospitalizations (torsemide, $845.84; furosemide, $893.33; P = 0.918) and CHF-related physician visits (torsemide, $138.80; furosemide, $164.09; P = 0.288). Quality of life was significantly better for patients in the torsemide group at month 4 (P = 0.017), but not at month 2 (P = 0.059) or month 6 (P = 0.269). The number of adverse events did not differ significantly between groups (torsemide, 221; furosemide, 287; P = 0.916). The results of this study appear to indicate that in a representative cross-section of managed care patients, those who received torsemide, despite higher drug-acquisition costs, had similar CHF/CV-related management costs compared with furosemide recipients.