Randomized trial of benznidazole for chronic Chagas’ cardiomyopathy.
N Engl J Med 2015 Sep 1
Carlos A. Morillo, M.D., Jose Antonio Marin-Neto, M.D., Ph.D., Alvaro Avezum, M.D., Ph.D., Sergio Sosa-Estani, M.D., Ph.D., M.P.H., Anis Rassi, Jr., M.D., Ph.D., Fernando Rosas, M.D., Erick Villena, M.D., Roberto Quiroz, M.D., Rina Bonilla, M.D., Constança Britto, Ph.D., Felipe Guhl, M.Sc., Elsa Velazquez, Ph.D., Laura Bonilla, M.Sc., Brandi Meeks, M.Eng., Purnima Rao-Melacini, M.Sc., Janice Pogue, Ph.D., Antonio Mattos, M.Sc., Janis Lazdins, M.D., Ph.D., Anis Rassi, M.D., Stuart J. Connolly, M.D., and Salim Yusuf, M.D., Ph.D. for the BENEFIT Investigators
The role of trypanocidal therapy in patients with established Chagas’ cardiomyopathy is unproven.
We conducted a prospective, multicenter, randomized study involving 2854 patients with Chagas’ cardiomyopathy who received benznidazole or placebo for up to 80 days and were followed for a mean of 5.4 years. The primary outcome in the time-to-event analysis was the first event of any of the components of the composite outcome of death, resuscitated cardiac arrest, sustained ventricular tachycardia, insertion of a pacemaker or implantable cardioverter–defibrillator, cardiac transplantation, new heart failure, stroke, or other thromboembolic event.
The primary outcome occurred in 394 patients (27.5%) in the benznidazole group and in 414 (29.1%) in the placebo group (hazard ratio, 0.93; 95% confidence interval [CI], 0.81 to 1.07; P=0.31). At baseline, a polymerase-chain-reaction (PCR) assay was performed on blood samples obtained from 1896 patients; 60.5% had positive results for Trypanosoma cruzi on PCR. The rates of conversion to negative PCR results (PCR conversion) were 66.2% in the benznidazole group and 33.5% in the placebo group at the end of treatment, 55.4% and 35.3%, respectively, at 2 years, and 46.7% and 33.1%, respectively, at 5 years or more (P<0.001 for all comparisons). The effect of treatment on PCR conversion varied according to geographic region: in Brazil, the odds ratio for PCR conversion was 3.03 (95% CI, 2.12 to 4.34) at 2 years and 1.87 (95% CI, 1.33 to 2.63) at 5 or more years; in Colombia and El Salvador, the odds ratio was 1.33 (95% CI, 0.90 to 1.98) at 2 years and 0.96 (95% CI, 0.63 to 1.45) at 5 or more years; and in Argentina and Bolivia, the odds ratio was 2.63 (95% CI, 1.89 to 3.66) at 2 years and 2.79 (95% CI, 1.99 to 3.92) at 5 or more years (P<0.001 for interaction). However, the rates of PCR conversion did not correspond to effects on clinical outcome (P=0.16 for interaction).
Trypanocidal therapy with benznidazole in patients with established Chagas’ cardiomyopathy significantly reduced serum parasite detection but did not significantly reduce cardiac clinical deterioration through 5 years of follow-up. (Funded by the Population Health Research Institute and others; ClinicalTrials.gov number, NCT00123916; Current Controlled Trials number, ISRCTN13967269.)