Abstract 248: Prospective Study of Ventricular Function and Survival in Acute Phase of Chagas Disease: An Animal Experimental Model

Abstract

Background: Acute Cardiomyopathy secondary to Chagas disease is often subclinical when related to vector transmission. However, cases related to non-vector transmission as in patients submitted to cardiac transplant may have fatal outcomes. This study aimed to assess survival during the acute phase of Chagas disease and its relation to the ventricular function in an animal experimental model. Methods: Female Syrian hamsters (n=45) were separated in two groups: control group (CG):15 animals injected with saline solution; and infected group (IG): 30 animals inoculated with 3,5x10 4 trypomastigote forms of Trypanosoma cruzi,Y strain . Both groups were monitored daily and submitted to echocardiography with equipment dedicated to small animals (Vevo® 2100) in two different moments: baseline (before infection) and 15 days post infection. Left ventricular ejection fraction (LVEF) and global longitudinal myocardial strain (GLS) of left ventricle were measured. The IG was divided into animals with and without clinical sign (CS+) of disease: weight or fur loss, mucous wounds and lethargy. ANOVA for mixed models was used to compare the ventricular function parameters among groups over time. Survival analysis was studied using Kaplan-Meier curves and logrank test. Results: Total time follow up was 60 days. LVEF in IG was significantly reduced through time (53.80 ± 4.95 to 43.55 ± 12.10%) compared to CG (57.86 ± 7.52 to 59.73 ± 5.87%) (p=0.002). There was also a significant reduction of GLS (-18.97 ± 3.94 to -12.44 ± 4.79%) in the IG compared to CG (-19.58 ± 4.03 to -19.67 ± 4.04%) (p=0.012). Twelve animals from IG died (40.00%,12 out of 30) compared to one from CG (6.66%, 1 out of 15). Eleven out of the 12 dead animals from IG, presented, before, clinical signs (CS+). Survival was significant reduced in the IG compared to CG over time (p=0.02) (Figure 1). Conclusion: Reduced survival during the acute phase of experimental model of Chagas disease is related to the significant reduction of left ventricular function. The mortality rate in the IG is higher in the group which presents CS+.