IJCS | Volume 31, Nº2, March / April 2018

184 Table 1 – Rassi score for mortality risk stratification in patients with chronic chagasic cardiopathy Clinical Characteristic Punctuation Male Gender 2 ECG with low QRS voltage 2 Nonsustained ventricular tachycardia 3 Global LV alteration or LV segmental motion 3 Cardiomegaly on chest x-ray 5 Heart failure FC III-IV (NYHA) 5 objective of evaluating the efficacy of this treatment. Trypanosomicidal treatment was only effective to detect negative parasitological test results evaluated by the polymerase chain reaction technique (PCR) (66% in the treatment group versus 34% in the control group) even though a negative result did not correlate with clinical benefit over the 5-year follow-up. 76 After the initial publication of the results, supplementary analysis comparing the outcomes verified in Brazil with the ones obtained in the other four countries allows the hypothesis that, probably due to the predominance of T. cruzi lineage II, which is more sensitive to the trypanocidal action of benznidazole, in Brazil, the effect of the etiological treatment may turn out to have a clinical benefit for chronically infected Brazilian patients without very advanced heart disease. 77 Thus, the treatment could be offered, on an individual basis, for patients with this profile, in order to reach a potential decision following sharing models with the responsible physician. Heart Failure Treatment Drug Therapy There is a clear lack of evidence supporting the clinical benefit of conventional systolic heart failure drug therapy, based primarily on neurohormonal block, in patients with CCC. However, considering that the general phenotype of HF caused by CCC is that of a dilated cardiomyopathy, the treatment for heart failure of other etiologies is empirically extrapolated for the treatment of patients suffering from CCC. This position was ratified by the recommendations of the Brazilian Guidelines on Diagnosis and Treatment of Chronic HF according to which all treatment recommendations were extended to the etiology of CCC. 78 However, certain particularities in the management of patients with HF secondary to CCCmust be highlighted. Several studies suggest that these patients exhibit a higher risk of symptomatic bradycardia and AV block with the use of beta-blockers, thus the heart rate in these patients must be carefully monitored. This precaution is especially applicable when, due to antiarrhythmic indication, amiodarone has already been initiated for the patient. In spite of this aspect, the results of a recent prospective observational cohort study suggest that beta-blockers can have a positive effect on the survival in patients with chronic HF caused by CCC. 79 Alternative therapies Several clinical studies have shown that the efficacy of the cardiac resynchronization therapy , throughmultisite pacemaker implantation, depends on the presence of left bundle branch block on ECG, a pattern found in the vast majority of patients included in large multicenter studies who have tested this therapy. However, due to evident predominance of RBBB, the usefulness of CRT in patients with CCC has not been demonstrated. Heart transplantation has been successfully used in patients with advancedHF secondary to CCC. 80 In a study of 117 patients with CCCwho received the transplant, the survival reported at 1, 4, 8 and 12 years after the procedure, was 71, 57, 55 and 46%, respectively. These observational studies show that the survival of patients with CCC was better than that observed in patients with HF of other etiologies, 81 which seems to be a consequence of several aspects, such as less advanced age and lower number of comorbidities in transplanted patients with CCC. This series of cases has also shown that the reactivationof the T cruzi infection is a common clinical problem, as a result ofpost-transplantation immunosuppression, andsometimes Simões et. al. Chagas Disease Cardiomyopathy Int J Cardiovasc Sci. 2018;31(2)173-189 Review Article