Noninvasive prognostic markers for cardiac death and ventricular arrhythmia in long-term follow-up of subjects with chronic Chagas' disease

Abstract

The objective of the present study was to investigate clinical, echocardiographic and electrocardiographic (12-lead resting ECG, 24-h ambulatory ECG monitoring and signal-averaged ECG (SAECG)) parameters in subjects with chronic Chagas' disease in a long-term follow-up as prognostic markers for adverse outcomes. Fifty adult outpatients (34 to 74 years old, 31 females) staged according to Los Andes class I, II or III and complaining of palpitation were enrolled in a longitudinal study. SAECG was analyzed in time and frequency domains and the endpoint was a composite of cardiac death and ventricular tachycardia. During a follow-up of 84.2 ± 39.0 months, 34.0% of the patients developed adverse outcomes (9 cardiac deaths and 11 episodes of ventricular tachycardia). After optimal dichotomization, in a stepwise multivariate Cox-hazard regression model, apical aneurysm (HR = 3.7; 95% CI = 1.2-1.3; P = 0.02), left ventricular ejection fraction <62% (HR = 4.60; 95% CI = 1.39-15.24; P = 0.01) and incidence of ventricular premature contractions >614 per 24 h (hazard ratio = 6.1; 95% CI = 1.7-22.6; P = 0.006) were independent predictors of the composite endpoint. Although a high frequency content in SAECG demonstrated association with the presence of left ventricular dysfunction and myocardial fibrosis, its predictive value for the composite endpoint was not significant. Apical aneurysms, reduced left ventricular function and a high incidence of ventricular ectopic beats over a 24-h period have a strong predictive value for a composite endpoint of cardiac death and ventricular tachycardia in subjects with chronic Chagas' disease.

Clinical and Echocardiographic Predictors of Mortality in Chagasic Cardiomyopathy - Systematic Review

“…Another important point to be considered is the absolute hegemony of studies carried out in Brazil (77% of those included in this review) 4,6-9,11,12,14-19,21-26,28-36,38,40-43 . Among the five studies performed in other countries, three were carried out in Latin America 13,20,27 and two in Europe 37,39 .…”

“…As for the addressed topics, 10 articles considered prognostic factors of mortality and risk of disease progression using echocardiography 13,19,22,23,26,28,30,32,35,36 , five studies assessed left ventricular ejection fraction (LVEF) 20,25,29,34,39 , alone or together with prognostic factors, seven articles assessed systolic and diastolic ventricular function with tissue Doppler 15-17,27,33,36,40 , five assessed concentrations of brain natriuretic peptide (BNP) 21,24,29,31,37 , one study assessed the prognostic value of troponin concentrations 18 , one study evaluated ventricular dyssynchrony 38 , two studies assessed cardiac dysautonomia 14,41 , two studies used two-dimensional echocardiography to assess ventricular deformation (strain, strain rate and twisting) 33,42 and one study addressed the proinflammatory and prothrombotic factors in Chagas disease 43 .…”

“…Among the left ventricular alterations, the presence of apical aneurysm, impaired left ventricular function and ventricular extrasystoles also acted as predictors of poor prognosis 28 , associated with increased left atrial volume, regardless of the clinical data and conventional echocardiographic parameters 20,22,32 . Left ventricular wall motion abnormalities in patients with normal systolic function were shown to be a predictor of ventricular function deterioration in chagasic patients with normal ECG and no symptoms or physical signs 25 .…”

“…Studies with group comparison 13-18,21,24,26,27,31,33,35,37,40,41 aimed to evaluate the clinical, hemodynamic and evolution aspects of Chagas cardiomyopathy, while those aimed to identifying morphological and functional characteristics related to prognosis and mortality did not employ this methodology 19,20,22,23,25,28-30,32,34,36,38,39 . The identification of the predominance of publications aimed to investigate adult patients (between the third and fourth decades of life), when compared to those involving adolescents, seems justified by the physiopathology of the disease.…”

Unveiling the uncertainty principle in the QRS complex offset detection on high resolution electrocardiography

“…Following the initial scientific interest generated by the method, expectations diminished over time due to significant variability in its predictive accuracy among different studies. However, during the past few years, its predictive value has been re-evaluated either alone or in conjunction with other stratification methods in several cardiac abnormalities (Lacroix et al, 1991;Madias, 2005;Grell et al, 2006;Benchimol-Barbosa, 2007;Ribeiro et al, 2008;Schoenenberger et al, 2008;Liew, 2010;Huebner et al, 2010;Marcus et al, 2010).…”