Chagas disease is still a major public health problem in Latin America. About 10 million people worldwide are estimated to be infected with Trypanosoma cruzi, mostly in Latin America and 20 to 30% of these individuals are expected to present cardiac complications during their lifetime . According to the Brazilian Ministry of Health, there are still about 2.5 million individuals living with chronic Chagas disease in Brazil and, in 2009, 4,700 deaths attributed primarily to Chagas disease were reported in Brazil .
Chagas disease has two distinct clinical phases, acute and chronic . The majority of acute cases are clinically silent and last for 6 to 8 weeks. Only less than 10% of acute cases will present a self-limiting febrile illness, which can be aggravated by acute myocarditis. The acute phase is followed by a chronic phase, which has three forms: indeterminate, cardiac, and digestive. The indeterminate chronic form is a long-lasting asymptomatic phase, when patients present reactive serologic tests for Chagas disease but there is no evidence of damage to any organ [3–5]. However, two or more decades after infection, 20 to 30% of the patients will progress to the cardiac form of the disease, when the majority of the deaths and severe complications related to the disease occur [6–8]. Patients at the chronic cardiac phase may manifest heart failure (HF), ventricular and atrial arrhythmias, atrioventricular blocks, thromboembolism, stroke, and sudden death [8–10], with a high economic and mortality burden. Another 10 to 15% of the patients at the chronic phase will present evidence of digestive disease characterized by complaints of dysphagia or constipation and radiologic evidence of megaesophagus or megacolon . An unspecified number of patients may present evidence of a mixed chronic form with evidence of both cardiac and digestive involvement .
Heart failure is a clinical syndrome that arises secondary to changes of cardiac structure or function that impair the ability of the left ventricle to fill or eject blood. The clinical manifestations are dyspnea, fatigue, and edema with impairment of functional capacity and quality of life of affected individuals. Heart failure is currently classified by the American Heart Association into four stages: A (patients at risk of developing HF); B (patients who have structural heart disease known to be associated with HF); C (patients with symptomatic HF); and D (patients with HF refractory to treatment) .
The treatment of patients with chronic Chagas heart disease is aimed at controlling symptoms and improving patients’ quality of life, by preventing cardiovascular complications, limiting disease progression, and increasing the overall survival rate of the patients. Unfortunately, there is no specific treatment against the parasite that can benefit patients at this stage, and treatment follows the guidelines issued to treat HF and arrhythmias due to complications caused by other etiologies .
In the proposed trial, we will focus on the contribution of pharmaceutical care to clinical treatment of patients with Chagas heart disease complicated by HF. The pharmacological treatment of patients with chronic Chagas heart disease complicated by HF includes such drugs as angiotensin-converting enzyme (ACE) inhibitors  or angiotensin II receptor blockers, beta blockers [14–18], aldosterone antagonists [18, 19], digitalis, and loop diuretics. Many of these pharmacological strategies can prolong the life expectancy of patients with HF and are recommended in patients with Chagas heart disease complicated by HF . Other drugs may be required as specific HF complications, such as atrial fibrillation, occur. For example, atrial fibrillation and ventricular arrhythmias will require drugs such as antiarrhythmics [12, 18, 20].
Another important aspect of HF treatment is the control of precipitating factors. Precipitating factors are any factors that can trigger an episode of decompensated HF. These include poor dietary or medical compliance, inappropriate discontinuation or reduction of HF therapy by the physician, use of medications known to worsen HF, inadequately treated hypertension, anemia, arrhythmias, and acute myocardial ischemia. Poor medical compliance and use of medications known to worsen HF, such as nonsteroidal anti-inflammatory drugs, calcium antagonists, thiazolidinediones, class I antiarrhythmic agents, and sotalol, are potentially preventable precipitating factors that can be minimized by pharmaceutical care [12, 21]. Pharmaceutical care is a practice performed by the clinical pharmacist who delivers the patient’s prescription, in order to improve compliance, avoid underuse of appropriate drugs and optimize their dosage, avoid use of inappropriate drugs, and detect, prevent, and resolve drug-related problems (DRPs)  and improve the patient’s quality of life . The value of this strategy has been demonstrated in distinct clinical scenarios [23–25]. In patients with HF, this intervention may improve patients’ symptoms, avoid hospitalizations, and, consequently, improve patients’ quality of life. In fact, small, short-term trials and observational data suggest that pharmaceutical care intervention reduces the risk of hospital admission and possibly mortality in patients with HF [26, 27].
Drug-related problems are health problems linked to drug therapy that may affect expected results of patients’ therapy and their quality of life, while causing a high economic and mortality burden . In the United States alone, the annual related costs of DRPs have been estimated as 177.4 billion dollars . Several factors may contribute to DRPs, such as access to drug therapy, noncompliance to drug therapy, prescription duplicity, ineffectiveness of drug therapy, adverse drug reactions (ADRs), and dosage above the therapeutic range .
Chronic diseases, such as HF, impose a great limitation on the patients’ quality of life  and the success of treatment strategies for HF is measured not only by the increase in event-free time survival but also by the improvement in the quality of life of the patient . Pharmaceutical care may improve a patient’s quality of life related to HF  and it is important to test this hypothesis in patients with Chagas heart disease complicated by HF, who, in Brazil, are mostly assisted in public outpatient services. Therefore, our aim is to evaluate the effect of pharmaceutical care, as compared with standard care, on the quality of life of patients with Chagas heart disease complicated by HF.