IJCS | Volume 31, Nº2, March / April 2018

183 Figure 5 – Delayed enhanced images where fibrosis can be seen as the white area inserted in the (dark) muscle, indicated by arrows. Left panel shows a small mesomyocardial area in the LV lateral wall in a four-chambered image. Right panel shows extensive transmural impairment of the posterolateral wall. in addition to changes in LV segmental parietal mobility. Thus, the requirement of coronary angiography is not uncommon to rule out the presence of coronary artery disease in patients with risk factors for this condition. As stressed above, in the vast majority of patients referred for cardiac catheterization, with CCC, the subepicardial coronary arteries are essentially normal or have non‑significant hemodynamically obstructive lesions. 42,59 Prognosis The prognosis of CCC depends on various factors, among them the stage of the disease presented by each patient, as already described in this text. In the chronic phase, in relation to the clinical form with LV impairment, several observational series have shown worse prognosis in patients with CCC compared to those with other heart diseases manifested by heart failure. In a recent prospective observational study, including 456 patients with heart failure, the 68 patients with CCC had lower survival compared to the ones with other etiologies. 71 Several pathophysiological factors can explain this difference, but some prognostic markers have already been defined as independent predictors, among them LV contractile dysfunction, both evaluated by echocardiography and suggested by cardiomegaly on chest x-ray. 4,72 The Rassi score, used for mortality risk stratification in patients with chronic chagasic cardiopathy, 9,73-75 consists of points assigned to simple characteristics and obtained through basic assignment methods (Table 1). This score allows detecting relevant extracts on the risk of mortality in patients with CCC. Over about 10 years of follow-up, patients classified as low risk (score from 0 to 6) had mortality of 9 to 10%; those with intermediate risk (score between 7 and 11) had mortality from 37 to 44% and those with high risk (score between 12 and 20) had mortality from 84 to 85%. The combination of LV systolic function (even if only regional) and NSVT was associated with a particularly elevated risk of mortality, of the order of 15.1 times. The detection of NSVT alone was associated with a 2.15 times increase in death. Figure 6 reproduces the algorithm for risk stratification in patients with CCC, derived from a systematic review of observational studies. 73 Treatment Etiological Treatment The role of antiparasitic agents in the treatment of T. cruzi infection is considerably limited in the chronic phase of Chagas heart disease, since much reversal of established tissue damage should not be expected at these advanced stages of the disease. 76 The BENEFIT study, 77 released in 2015, was the only large-scale clinical trial carried out on Chagas Disease. The study randomized 2854 patients, who received benznidazole or placebo, with the essential Simões et. al. Chagas Disease Cardiomyopathy Int J Cardiovasc Sci. 2018;31(2)173-189 Review Article