Treatment of Chagas' disease with itraconazole: electrocardiographic and parasitological conditions after 20 years of follow-up.

Objectives: To evaluate cases of chronic Chagas' disease for the long-term effects of treatment with itraconazole on Trypanosoma cruzi infections and the regression or development of ECG abnormalities.

Methods: In March 1992, we treated 46 patients with chronic Chagas' disease with 6 mg/kg/day of itraconazole for 120 days in a blind evaluation. The patients came from an area of Chile where the disease was endemic and were checked for ECG abnormalities and with xenodiagnosis (XD) or real-time XD-quantitative PCR (XD-qPCR) for Trypanosoma cruzi infection before treatment and once a year for 20 years.

Results: Twenty-one patients proved to be uninfected after 20 years and 15 of the patients had a normal ECG. Of the latter cases, 32.6% could be considered cured, although all of them had positive serology. Itraconazole prevents the development of ECG abnormalities, because after 20 years of treatment only 10.86% of patients developed ECG abnormalities (Z = 1.70, P = 0.046). XD-qPCR performed on 16 patients demonstrated 10 cases with <1.42 parasites/mL: eight with <1 parasite/mL, one with 1.42 parasites/mL and one with 1.01 parasites/mL. Five patients had more than 11.75 parasites/mL, all of them with a positive XD; these cases correspond to therapy failure, since re-infection was ruled out. In one case, XD-qPCR did not present amplification.

Conclusions: Itraconazole is useful in the treatment of chronic Chagas' disease as it prevented the development of ECG abnormalities and cured 32.6% of patients.