Chagas disease, a cause of serious cardiovascular problems and sudden death, was previously localized mainly in the tropics, but now affects at least 300,000 people in the United States and is growing in prevalence in other traditionally nonendemic areas, including Europe, Australia, and Japan. The American Heart Association and the Inter-American Society of Cardiology have released a statement to “increase global awareness among providers who may encounter patients with Chagas disease outside of traditionally endemic environments.”
Dr. Mae Melvin/CDC
The document summarizes the most up-to-date information on diagnosis, screening, and treatment of Trypanosoma cruzi (the protozoan cause of Chagas) infection, focusing primarily on its cardiovascular aspects, and was developed by Maria Carmo Pereira Nunes, MD, chair, and her colleagues on the American Heart Association Rheumatic Fever, Endocarditis and Kawasaki Disease Committee.
Chagas disease is transmitted by a blood-sucking insect vector Triatoma infestans and, less frequently, from mother to fetus or by contaminated food or drink, and about one third of infected individuals develop chronic heart disease.
Although 60%-70% of people infected with T. cruzi never develop any symptoms, those who do can develop heart disease, including heart failure, stroke, life threatening ventricular arrhythmias, and cardiac arrest, according to the statement published in Circulation.
Chronic Chagas-related heart disease develops after several decades of the indeterminate, or subclinical, form of the disease following the initial acute infection. Potential risk factors for progression to the chronic stage include African ancestry, age, severity of acute infection, nutritional status, alcoholism, and their concomitant diseases.
In most studies, sudden death is the most common overall cause of death in patients with Chagas-related cardiomyopathy (55%-60%), followed by heart failure (25%-30%) and embolic events (10%-15%), according to the authors.
Benznidazole and nifurtimox are the only drugs with proven efficacy against Chagas disease, with benznidazole as the first-line treatment because it has better tolerance, is more widely available, and has more published data published on its efficacy. Furthermore, it is available in the United States, after the Food and Drug Administration granted fast-track approved 2017 for treatment of Chagas disease. Use of nifurtimox in the United States entails consultation with the Centers for Disease Control and prevention, according to the statement.
“More data are needed on the best practices for the treatment of Chagas cardiomyopathy. Because no specific clinical trials have been conducted, care for
patients with Chagas-induced ventricular dysfunction is extrapolated from general heart failure recommendations with unclear efficacy (and potential harm),” Dr. Pereira Nunes and her colleagues concluded.
One author disclosed receiving a research grant from Merck and speakers’ bureau and/or honoraria from Bayer; Biotronik, and Medtronic. The others had no relevant disclosures.
SOURCE: Nunes, MCP, et al., Circulation. 2018 Aug 20; doi: 10.1161/CIR.0000000000000599.