Circulating Trypanosoma Cruzi Load and Major Cardiovascular Outcomes in Patients with Chronic Chagas Cardiomyopathy: A Prospective Cohort Study.

Objectives To analyse the effect of parasite load assessed by quantitative reverse transcription PCR (RT-qPCR) in serum on the prognosis of patients with chronic Chagas cardiomyopathy (CCM) after a 2-year follow-up. Methods Prospective cohort study conducted between 2015 and 2017. One hundred patients with CCM were included. Basal parasitaemia levels ofTrypanosoma cruzi(T. cruzi)were measured using a quantitative polymerase chain reaction (qPCR) test. The primary composite outcome (CO) was all-cause mortality, cardiac transplantation and implantation of a left ventricular assist device. Secondary outcomes were the baseline levels of serum biomarkers and echocardiographic variables. Results After a 2 years of follow-up, the primary CO rate was 16%. A positive qPCR was not associated with a higher risk of the CO. However, when parasitaemia was evaluated by comparing tertiles (tertile 1: undetectable parasitaemia, tertile 2: low parasitaemia and tertile 3: high parasitaemia), a higher risk of the CO (HR 3.66; 95% CI 1.11-12.21) was evidenced in tertile 2. Moreover, patients in tertile 2 had significantly higher levels of high-sensitivity troponin T and cystatin C and more frequently exhibited an ejection fraction T. cruziload more efficiently, but be associated with increased myocardial damage. Additional studies with a larger number of patients and cytokine measurement are required to support this hypothesis.