Predictors of Trypanosoma cruzi PCR positivity in patients with chronic Chagas disease.

BACKGROUND: A positive Trypanosoma cruzi polymerase chain reaction (PCR) is associated with a worse prognosis in patients with chronic Chagas disease (CD). OBJECTIVES: To study the association of clinical, electrocardiographic, and echocardiographic characteristics and biomarker blood levels with positive T. cruzi PCR in chronic CD. METHODS: This is a single-centre observational cross-sectional study. Positive T. cruzi PCR association with clinical, electrocardiographic, and echocardiographic characteristics, and biomarker blood levels were studied by logistic regression analysis. p values < 0.05 were considered significant. FINDINGS: Among 333 patients with chronic CD (56.4% men; 62 ± 10 years), T. cruzi PCR was positive in 41.1%. Stepwise multivariate logistic regression showed an independent association between positive T. cruzi PCR and diabetes mellitus {odds ratio (OR) 0.53 [95% confidence interval (CI) 0.30-0.93]; p = 0.03}, right bundle branch block [OR 1.78 (95% CI 1.09-2.89); p = 0.02], and history of trypanocidal treatment [OR 0.13 (95% CI 0.04-0.38); p = 0.0002]. Among patients with a history of trypanocidal treatment (n = 39), only four (10%) patients had a positive T. cruzi PCR. MAIN CONCLUSIONS: Among several studied parameters, only diabetes mellitus, right bundle branch block, and history of trypanocidal treatment showed an independent association with positive T. cruzi PCR. History of trypanocidal treatment was a strong protective factor against a positive T. cruzi PCR.

Two-dimensional strain derived parameters provide independent predictors of progression to Chagas cardiomyopathy and mortality in patients with Chagas disease.

BACKGROUND: Patients with chronic Chagas disease (CD) cardiomyopathy have a high mortality. We evaluated if two-dimensional (2D) strain (ε) parameters provide independent predictors of progression to CD cardiomyopathy and all-cause mortality. METHODS: A total of 408 patients with chronic CD (58.6% women; 53 ± 11 years; clinical forms: indeterminate 34.1%, cardiac 57.6%, digestive 1.2%, cardiodigestive 7.1%) were consecutively included in this single-center prospective longitudinal study. Echocardiographic evaluation included left atrial and left ventricular (LV) function on ε analyses. Primary end-point was a composite of all-cause mortality or heart transplant. Secondary end-point was CD progression defined as the occurrence of changes typical of CD in electrocardiogram, sustained ventricular tachycardia, wall motion abnormalities, or heart failure among patients with the indeterminate form at baseline. Multivariable Cox-proportional-hazards regression analyses were performed to test if 2D ε parameters were associated with the studied end-points. P values < 0.05 were considered significant. RESULTS: The primary end-point occurred in 91 patients after a follow-up of 6.5 ± 2.7 years. CD progression occurred in 26 out of 144 patients without cardiac form at baseline (2.88 cases/100 patient-years). Peak LV circumferential (HR 1.09, 95% CI 1.01-1.18, P = .02) and radial (HR 0.97, 95% CI 0.95-0.99, P = .007) ε, and LV torsion (HR 0.51, 95% CI 0.35-0.74, P = .0004) were independent predictors of the primary end-point. Peak LV radial ε (HR 0.96, 95% CI 0.93-0.99, P = .03) was an independent predictor of CD progression. CONCLUSIONS: Therefore, 2D ε derived parameters can be useful for CD progression and mortality prediction.

Chagas heart disease: An overview of diagnosis, manifestations, treatment, and care.

Chagas heart disease (CHD) affects approximately 30% of patients chronically infected with the protozoa Trypanosoma cruzi. CHD is classified into four stages of increasing severity according to electrocardiographic, echocardiographic, and clinical criteria. CHD presents with a myriad of clinical manifestations, but its main complications are sudden cardiac death, heart failure, and stroke. Importantly, CHD has a higher incidence of sudden cardiac death and stroke than most other cardiopathies, and patients with CHD complicated by heart failure have a higher mortality than patients with heart failure caused by other etiologies. Among patients with CHD, approximately 90% of deaths can be attributed to complications of Chagas disease. Sudden cardiac death is the most common cause of death (55%-60%), followed by heart failure (25%-30%) and stroke (10%-15%). The high morbimortality and the unique characteristics of CHD demand an individualized approach according to the stage of the disease and associated complications the patient presents with. Therefore, the management of CHD is challenging, and in this review, we present the most updated available data to help clinicians and cardiologists in the care of these patients. We describe the clinical manifestations, diagnosis and classification criteria, risk stratification, and approach to the different clinical aspects of CHD using diagnostic tools and pharmacological and non-pharmacological treatments.

Left Atrial Structure and Function Predictors of New-Onset Atrial Fibrillation in Patients with Chagas Disease.

BACKGROUND: Atrial fibrillation (AF) carries ominous consequences in patients with Chagas disease. The aim of this study was to determine whether left atrial (LA) volume and function assessed using three-dimensional echocardiographic (3DE) imaging and two-dimensional speckle-tracking echocardiographic deformation analysis of strain (ε) could predict new-onset AF in patients with Chagas disease. METHODS: A total of 392 adult patients with chronic Chagas disease (59% women; mean age, 53 ± 11 years) who underwent echocardiography were consecutively enrolled in this prospective longitudinal study. Echocardiographic evaluation included two-dimensional (2D) Doppler echocardiography, with evaluation of left ventricular systolic and diastolic function, LA size, and LA and left ventricular function on 3DE and ε analyses. Multivariate Cox proportional-hazards regression analysis models adjusting for age, sex, hypertension, presence of a pacemaker, and 2D Doppler echocardiographic parameters were used to test if the variables of interest had independent prognostic value for AF prediction. RESULTS: Patients with Chagas disease were followed for 5.6 ± 2.7 years. Among these, 139 (35.5%) had the indeterminate form, 224 (57.1%) had the cardiac form, five (1.3%) had the digestive form, and 24 (6.1%) had the cardiodigestive form. The study end point of AF occurred in 45 patients. Total LA emptying fraction (hazard ratio, 0.93; 95% CI, 0.89-0.98; P = .002), passive LA emptying fraction (HR, 0.95; 95% CI, 0.91-0.99; P = .02), and peak negative global LA ε (HR, 1.22; 95% CI, 1.05-1.41; P = .01) were predictors of new-onset AF independent of clinical and 2D Doppler echocardiographic parameters. CONCLUSIONS: LA function assessed on 3DE and ε analyses predicts new-onset AF in patients with Chagas disease independent of clinical and 2D Doppler echocardiographic indexes.

The impact of exercise frequency upon microvascular endothelium function and oxidative stress among patients with coronary artery disease.

PURPOSE: This study compared the effects of low and high weekly exercise frequencies on microvascular endothelium function and oxidative stress among patients with coronary artery disease. METHODS: Thirty-four male patients completed a 6-month cardiac rehabilitation programme, from which 23 performed exercise with a high frequency (HF) and 11 with a low frequency (LF). Systemic microvascular blood flow, maximal aerobic capacity, blood lipids, oxidative stress and anthropometric data were assessed prior to and after the cardiac rehabilitation programme. Microvascular blood flow was assessed in the skin of the forearm using laser speckle contrast imaging coupled with iontophoresis of acetylcholine. RESULTS: Maximal aerobic capacity, biochemical analysis and anthropometric data were similar between groups prior to and after the cardiac rehabilitation programme (P>0·05). However, after 6 months of cardiac rehabilitation performed with HF, there was an increase in the peak response to acetylcholine compared with LF (83·5 ± 58·5 versus 21·8 ± 22·4%; P<0·05). Changes in lipid peroxidation (HF: -5·5 ± 9·4 versus LF: 2·2 ± 12·0 pmol MDA mg-1 ; P = 0·19), catalase activity (HF: 0·07 ± 0·17 versus LF: 0·04 ± 0·08 U mg-1 ; P = 0·74) and nitric oxide levels (HF: 1·8 ± 15·3 versus LF: -3·2 ± 12·3 µM; P = 0·36) were similar between groups after cardiac rehabilitation. CONCLUSION: Six months of aerobic exercise training performed with high frequency is preferable to low frequency aiming endothelium microvascular function increases in patients with coronary artery disease. The mechanisms involved in this response are unclear and warrant additional research.

Predictors of Trypanosoma cruzi PCR positivity in patients with chronic Chagas disease

BACKGROUND A positive Trypanosoma cruzi polymerase chain reaction (PCR) is associated with a worse prognosis in patients with chronic Chagas disease (CD). OBJECTIVES To study the association of clinical, electrocardiographic, and echocardiographic characteristics and biomarker blood levels with positive T. cruzi PCR in chronic CD. METHODS This is a single-centre observational cross-sectional study. Positive T. cruzi PCR association with clinical, electrocardiographic, and echocardiographic characteristics, and biomarker blood levels were studied by logistic regression analysis. p values < 0.05 were considered significant. FINDINGS Among 333 patients with chronic CD (56.4% men; 62 ± 10 years), T. cruzi PCR was positive in 41.1%. Stepwise multivariate logistic regression showed an independent association between positive T. cruzi PCR and diabetes mellitus {odds ratio (OR) 0.53 [95% confidence interval (CI) 0.30-0.93]; p = 0.03}, right bundle branch block [OR 1.78 (95% CI 1.09-2.89); p = 0.02], and history of trypanocidal treatment [OR 0.13 (95% CI 0.04-0.38); p = 0.0002]. Among patients with a history of trypanocidal treatment (n = 39), only four (10%) patients had a positive T. cruzi PCR. MAIN CONCLUSIONS Among several studied parameters, only diabetes mellitus, right bundle branch block, and history of trypanocidal treatment showed an independent association with positive T. cruzi PCR. History of trypanocidal treatment was a strong protective factor against a positive T. cruzi PCR.