BENznidazole Evaluation For Interrupting Trypanosomiasis - BENEFIT


The goal of the trial was to evaluate treatment with benznidazole compared with placebo among subjects with chronic cardiomyopathy and serologic evidence of Trypanosoma cruzi.

Contribution to the Literature: The BENEFIT trial showed that benznidazole did not benefit patients with Chagas’ cardiomyopathy.

Study Design

  • Randomized
  • Parallel
  • Placebo
  • Blinded

Subjects with positive serologic tests for T. cruzi and cardiomyopathy were randomized to benznidazole 300 mg daily for 40-80 days (n = 1,431) vs. placebo (n = 1,423).

Inclusion criteria:

  • Subjects at least 18 years of age with at least two positive serologic tests for T. Cruzi and cardiomyopathy
  • Total number of enrollees: 2,854
  • Duration of follow-up: 7 years
  • Mean patient age: 55 years
  • Percentage female: 49%

Principal Findings:

Polymerase-chain-reaction (PCR) conversion rate (from positive to negative) was 66.2% in the benznidazole group vs. 33.5% in the placebo group (p < 0.001). 

The primary 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 occurred in 27.5% of the benznidazole group vs. 29.1% of the placebo group (p = 0.31).

Secondary outcomes:

  • Death: 17.2% vs. 18.1%, respectively, for benznidazole vs. placebo
  • New or worsening heart failure: 7.6% vs. 8.6%, respectively, for benznidazole vs. placebo


Among patients with serologic evidence of T. Cruzi and chronic cardiomyopathy, benznidazole did not prevent adverse cardiac events compared with placebo at 7 years. This lack of benefit was despite a higher rate of T. Cruzi conversion to negative status among the benznidazole group. While early T. Cruzi infection warrants treatment, there is no apparent benefit from treating patients with established Chagas’ cardiomyopathy.


Morillo CA, Marin-Neto JA, Avezum A, et al. Randomized trial of benznidazole for chronic Chagas’cardiomyopathy. N Engl J Med 2015;Sep 1:[Epub ahead of print].

Maguire JH. Treatment of Chagas’ Disease — Time Is Running Out. N Engl J Med 2015;Sep 1:[Epub ahead of print].

Presented by Dr. Carlos A. Morillo at the European Society of Cardiology Congress, London, September 1, 2015.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Implantable Devices, SCD/Ventricular Arrhythmias, Cardiac Surgery and Arrhythmias, Cardiac Surgery and Heart Failure, Acute Heart Failure, Heart Transplant

Keywords: Chagas Cardiomyopathy, Chagas Disease, Defibrillators, Implantable, Heart Arrest, Heart Failure, Heart Transplantation, Nitroimidazoles, Pacemaker, Artificial, Polymerase Chain Reaction, Stroke, Tachycardia, Ventricular, Trypanosoma cruzi, ESC Congress

< Back to Listings