T. cruzi-seropositivity associated with higher incidence of cardiomyopathy: Study

There are few contemporary cohorts of Trypanosoma cruzi-seropositive individuals, and the basic clinical epidemiology of Chagas disease is poorly understood. A team of researchers conducted a study to report the incidence of cardiomyopathy and death associated with T. cruzi seropositivity.

Participants were selected in blood banks at 2 Brazilian centres. Cases were defined as T. cruzi-seropositive blood donors. T. cruzi-seronegative controls were matched for age, sex, and period of donation. Patients with established Chagas cardiomyopathy were recruited from a tertiary outpatient service. Participants underwent a medical examination, blood collection, electrocardiogram, and echocardiogram at enrollment (2008 to 2010) and at follow-up (2018 to 2019). The primary outcomes were all-cause mortality and development of cardiomyopathy, defined as the presence of a left ventricular ejection fraction <50% and/or QRS complex duration ≥ 120 ms. To handle a loss to follow-up, a sensitivity analysis was performed using inverse probability weights for selection.

The results of the study are as follows:

· They enrolled 499 T. cruzi-seropositive donors, 488 T. cruzi-seronegative donors, and 101 patients with established Chagas cardiomyopathy.

· The mortality in patients with established cardiomyopathy was 80.9 deaths/1000 person-years (py) and 15.1 deaths/1000 py in T. cruzi-seropositive with cardiomyopathy at baseline.

· Among T. cruzi-seropositive donors without cardiomyopathy at baseline mortality was 3.7 events/1000py (15/385, 4%), which was no different from T. cruzi-seronegative donors with 3.6 deaths/1000py (17/488, 3%).

· The incidence of cardiomyopathy in T. cruzi-seropositive donors was 13.8 compared with 4.6 events/1000 py (11/277, 4%) in seronegative controls, with an absolute incidence difference associated with T. cruzi seropositivity of 9.2 events/1000py. T. cruzi antibody level at baseline was associated with the development of cardiomyopathy.

Thus, the researchers concluded by presenting a comprehensive description of the natural history of T. cruzi seropositivity in a contemporary patient population. The results highlight the central importance of anti-T. cruzi antibody titer as a marker of Chagas disease activity and risk of progression.

Reference:

Incidence and Predictors of Progression to Chagas Cardiomyopathy: Long-Term Follow-Up of Trypanosoma Cruzi Seropositive Individuals by Nunes M et. al published in the Circulation.

https://doi.org/10.1161/CIRCULATIONAHA.121.055112