Atorvastatin on Inflammation and Cardiac Function in Chronic Chagas Disease

Overview

Chagas Disease, caused by the parasite Trypanosoma cruzi afflicts 7 million people in Latin America, and due to migration, abroad. The diagnosis lies in clinical suspicion and serologic detection of antibodies. Cardiac evaluation is essential because complications, including heart failure and arrhythmias, are the main causes of disability and death. Heart involvement is explained by a parasite-dependent, immune-mediated myocardial and microvascular injuries. Current treatment includes the administration of nifurtimox or benznidazole, although in the chronic phase their efficacy is low and may induce severe adverse events, forcing the suspension of the therapy. Therefore, finding innovative approaches to improve the efficacy of the current antichagasic drugs by modifying the inflammatory response would render the current treatment more effective. Pre-clinical evidence supports the idea that the cholesterol-lowering statin drugs, such as atorvastatin, may contribute to decrease cardiac inflammation, reduce endothelial activation, and improve cardiac function. Atorvastatin therapeutic and safety profiles are well known, as is its mechanism of action, shared by the other members of the statin class. This trial aims at evaluating whether atorvastatin, in combination with antichagasic therapy, is safe and more efficacious in reducing general inflammation than an antiparasitic therapy alone, by improving endothelial and cardiac functions. This proof-of-concept trial will be double-blinded, randomized, and multicentered with a phase II design. To achieve this aim, it will be evaluated the efficacy of the combination of atorvastatin and antichagasic therapy (nifurtimox or benznidazole) to reduce inflammatory cytokine plasma levels, soluble endothelial cell adhesion molecules, and confirm the improvement of the cardiac function by electrocardiogram and two-dimensional echocardiogram. The trial will set the safety and tolerability of the combination of atorvastatin with antichagasic therapy by monitoring the incidence of adverse events and discontinuation of the therapy. This trial will be conducted with a sample size of 300 adult patients in four hospitals located in Santiago and Valparaiso, Chile.

Chagas disease (CD) afflicts 7 million people in 21 endemic countries in Latin America and is increasing in non-endemic countries due to migration. Control programs are discontinuous and current therapy is limited due to low efficacy. Different biomarkers have been proposed to evaluate progression, prognosis, or response to treatment; but, none has demonstrated sufficient specificity to be a gold standard for CD diagnosis. However, brain natriuretic peptide (BNP) and cardiac troponin T (cTnT) have been proposed as useful biomarkers to predict progress towards left ventricular dysfunction. Chronic Chagas Cardiomyopathy (CCC) is caused by a parasite-dependent, immune-mediated myocardial damage, which is the most critical determinant of the disease where the T helper 1/T helper 2 /T regulatory response is a crucial feature, where the equilibrium between excessive pro-inflammatory (Interferon-γ, tumor necrosis factor-α, IL-1β) and anti-inflammatory (IL-4, IL-10) cytokines is critical for cardiac damage development. Also, microvascular abnormalities and ischemia secondary to platelet activation and endothelial dysfunction, as evidenced by increases in cell adhesion molecules Intercellular Adhesion Molecule type 1 (ICAM-1), Vascular Cell Adhesion Molecule (VCAM), and E-selectin, including their soluble forms. Treatment of CCC and improvement strategies: In Chile, the etiologic treatment of CD in Chile is done with 5-10 mg/kg/day nifurtimox (NFX) or 5 mg/kg/day benznidazole (BZD) for 60 days. Drug therapy during the acute phase, congenital disease, and early indeterminate phase has a satisfactory efficacy and is considered curative. However, it is more difficult to declare a cure for chronic infection because current evidence of drug efficacy in this phase is weak or controversial, especially when mortality is considered. There are molecules involved in the natural resolution of inflammation. These specialized pro-resolving mediators include several lipids that control the magnitude and duration of local inflammation. These lipids are derived from essential fatty acids present in the plasma membrane, such as arachidonic acid or docosahexaenoic acid. Interestingly, aspirin and cholesterol-lowering statins, including atorvastatin can induce the synthesis of such molecules. Thus, a combination of trypanocidal drugs and those inducing resolution of the inflammatory process derived from parasite persistence could be a sound therapeutic strategy to prevent chronic consequences of CD. There is a general agreement that adults with chronic indeterminate CD are the population with the most urgent requirements for the development of new treatments because of the highest disease burden to these patients. Thus, improving the host's factors (e.g., the immune reaction elicited) may increase the efficacy of the conventional antichagasic therapy, probably by a decrease in the dose, a decrease in its duration, or both. The therapeutic and safety profiles of atorvastatin are well known, as is its mechanism of action and pharmacological actions, including the anti-inflammatory properties, shared by the other members of the statin class. Importantly, due to the low incidence of severe adverse events and efficacy, is one of the most widely used statins today. 20-80 mg/day atorvastatin is used to decrease the so-called LDL cholesterol involved in the pathogenesis of atherosclerotic cardiovascular disease. Thus, this trial aims at evaluating whether atorvastatin, in combination with antichagasic therapy, is safe and more efficacious in reducing general inflammation than an antiparasitic therapy alone, by improving endothelial and cardiac functions. This proof-of-concept trial will be double-blinded, randomized, and multicentered with a phase II design. To achieve this aim, it will be evaluated the efficacy of the combination of atorvastatin and antichagasic therapy (nifurtimox or benznidazole) to reduce inflammatory cytokine plasma levels, soluble endothelial cell adhesion molecules, and confirm the improvement of the cardiac function by electrocardiogram and two-dimensional echocardiogram. This clinical trial will be conducted in four centers located in the cities of Santiago and Valparaiso, Chile. In all those centers, well-established Programs for Chagas Control (PCC) are ongoing.