Global longitudinal strain as a predictor of outcomes in chronic Chagas´ cardiomyopathy

Introduction

Chronic Chagas cardiomyopathy (CCC) is associated with a high incidence of cardiovascular events. Global longitudinal strain (GLS) is useful in predicting adverse cardiovascular outcomes in several cardiomyopathies. However, its prognostic value in CCC is not well established.

Methods

This study was a retrospective echocardiography analysis with prospective follow-up of CCC subjects. GLS was defined as the average of three apical peak longitudinal strain measurements of the LV using vendor-independent software. GLS groups were defined according to tertiles: (1) GLS ≤ -18.4%, (2) GLS > -18.4% and <-13.8%, and (3) GLS ≥ -13.8%. The primary outcome was a composite of death, hospitalization, sustained ventricular tachycardia (SVT), new heart failure, any systemic embolism, hospitalization, reverted cardiac arrest and cardiac heart transplantation.

Results

GLS was obtained in 77 subjects, 50.6% were males and the mean age was 56 ± 15 years. There were 6.49% losses of follow-up and the mean LVEF was 51 ± 14%. After a follow-up period of 35 ± 19 months (2.9 y), 33 subjects reached the composite outcome. Death and hospitalization were the most frequent outcomes (n = 9), followed by new heart failure (n = 6), embolism (n = 6), and SVT (n = 3). The GLS ≥ -13.8% was associated with a worse prognosis when compared with the other tertile GLS groups (log rank-p-value = 0.001 for both comparisons). On the multivariate Cox proportional hazard model, adjusting for age, gender, and LVEF, GLS was an independent predictor of outcomes with an HR of 1.20 (CI = 1.05-1.38;p = 0.008).

Conclusion

Left ventricle GLS is an independent predictor of cardiovascular outcomes in patients with CCC. GLS may be an important tool for Chagas disease risk stratification, independent of LVEF.