Effect of Hydroxyurea on Mortality and Morbidity in Adult Sickle Cell Anemia: Risks and Benefits Up to 9 Years of Treatment

• Published in: JAMA : the journal of the American Medical Association 2003-04, Vol.289 (13), p.1645-1651
• Main Authors: Steinberg, Martin H, Barton, Franca, Castro, Oswaldo, Pegelow, Charles H, Ballas, Samir K, Kutlar, Abdullah, Orringer, Eugene, Bellevue, Rita, Olivieri, Nancy, Eckman, James, Varma, Mala, Ramirez, Gloria, Adler, Brian, Smith, Wally, Carlos, Timothy, Ataga, Kenneth, DeCastro, Laura, Bigelow, Carolyn, Saunthararajah, Yogen, Telfer, Margaret, Vichinsky, Elliott, Claster, Susan, Shurin, Susan, Bridges, Kenneth, Waclawiw, Myron, Bonds, Duane, Terrin, Michael
• Format: Article
• Language: English
• Subjects: Adult; Anemia, Sickle Cell - drug therapy; Anemia, Sickle Cell - mortality; Anemia, Sickle Cell - physiopathology; Antisickling Agents - therapeutic use; Biological and medical sciences; Blood Cell Count; Blood. Blood coagulation. Reticuloendothelial system; Cause of Death; Clinical outcomes; Double-Blind Method; Drug therapy; Fetal Hemoglobin - metabolism; Follow-Up Studies; Humans; Hydroxyurea - therapeutic use; Medical sciences; Morbidity; Mortality; Pharmacology. Drug treatments; Risk Assessment; Sickle cell anemia; Survival Analysis
• ISSN: 0098-7484; 1538-3598
• DOI: 10.1001/jama.289.13.1645

CONTEXT Hydroxyurea increases levels of fetal hemoglobin (HbF) and decreases morbidity from vaso-occlusive complications in patients with sickle cell anemia (SCA). High HbF levels reduce morbidity and mortality. OBJECTIVE To determine whether hydroxyurea attenuates mortality in patients with SCA. DESIGN Long-term observational follow-up study of mortality in patients with SCA who originally participated in the randomized, double-blind, placebo-controlled Multicenter Study of Hydroxyurea in Sickle Cell Anemia (MSH), conducted in 1992-1995, to determine if hydroxyurea reduces vaso-occlusive events. In the MSH Patients' Follow-up, conducted in 1996-2001, patients could continue, stop, or start hydroxyurea. Data were collected during the trial and in the follow-up period. SETTING Inpatients and outpatients in 21 sickle cell referral centers in the United States and Canada. PATIENTS Two-hundred ninety-nine adult patients with frequent painful episodes enrolled in the follow-up. Follow-up data through May 2001 were complete for 233 patients. INTERVENTION In the MSH, patients were randomly assigned to receive hydroxyurea (n = 152) or placebo (n = 147). MAIN OUTCOME MEASURE Mortality, HbF levels, painful episodes, acute chest syndrome, and blood cell counts. The randomized trial was not designed to detect specified differences in mortality. RESULTS Seventy-five of the original 299 patients died, 28% from pulmonary disease. Patients with reticulocyte counts less than 250 000/mm3 and hemoglobin levels lower than 9 g/dL had increased mortality (P = .002). Cumulative mortality at 9 years was 28% when HbF levels were lower than 0.5 g/dL after the trial was completed compared with 15% when HbF levels were 0.5 g/dL or higher (P = .03 ). Individuals who had acute chest syndrome during the trial had 32% mortality compared with 18% of individuals without acute chest syndrome (P = .02). Patients with 3 or more painful episodes per year during the trial had 27% mortality compared with 17% of patients with less frequent episodes (P = .06). Taking hydroxyurea was associated with a 40% reduction in mortality (P = .04) in this observational follow-up with self-selected treatment. There were 3 cases of cancer, 1 fatal. CONCLUSIONS Adult patients taking hydroxyurea for frequent painful sickle cell episodes appear to have reduced mortality after 9 of years follow-up. Survival was related to HbF levels and frequency of vaso-occlusive events. Whether indications for hydroxyurea treatm