Evaluation of Cardiac Mechanics by Speckle Tracking as a Prognostic Tool in Patients With Chagas Cardiomyopathy
Evaluation of Cardiac Mechanics by Speckle Tracking as a Prognostic Tool in Patients With Chagas Cardiomyopathy
This study aims to evaluate the prognostic value of myocardial mechanics parameters, including global longitudinal strain (GLS) and mechanical dispersion (MD), assessed through speckle tracking echocardiography, in patients with Chagas cardiomyopathy (CCM). The study is divided into two arms: a cross-sectional arm and a longitudinal arm. The cross-sectional arm compares echocardiographic parameters between patients with and without implantable cardioverter defibrillators (ICD) for secondary prevention. The longitudinal arm assesses clinical outcomes over 24 months. Primary outcomes include all-cause mortality and hospitalization due to heart failure, while secondary outcomes encompass sudden cardiac death, sustained ventricular tachycardia, embolic events, and persistent atrial fibrillation.
The study is divided into two phases:
Cross-sectional phase: Patients with CCM and LV ejection fraction (LVEF) ≤50% will be categorized into two groups based on the presence or absence of an ICD for secondary prevention. GLS and MD parameters will be evaluated to determine their association with higher-risk patients.
Longitudinal phase: Patients from the cross-sectional phase will be followed for 24 months to assess primary outcomes (all-cause mortality and heart failure hospitalization) and secondary outcomes (sudden cardiac death, sustained ventricular tachycardia, embolic events, and persistent atrial fibrillation). Prognostic utility of GLS and MD will be compared with traditional parameters.
Study Design:
Study Type: Observational
Estimated Enrollment: 153 participants
Observational Model: Cohort
Time Perspective: Prospective
Study Start Date: [To be added]
Primary Completion Date: [To be added]
Study Completion Date: [To be added]
Outcome Measures:
Primary Outcome Measures:
All-cause mortality (Time Frame: 24 months)
Hospitalization due to heart failure (Time Frame: 24 months)
Secondary Outcome Measures:
Sudden cardiac death (Time Frame: 24 months)
Sustained ventricular tachycardia (Time Frame: 24 months)
Embolic events (Time Frame: 24 months)
Persistent atrial fibrillation (Time Frame: 24 months)
Eligibility Criteria:
Inclusion Criteria:
Age 18-70 years
Diagnosed Chagas disease confirmed by two serological tests
LVEF ≤50% (Simpson's method)
Clinically stable for at least three months
Sinus rhythm or paced atrial rhythm on ECG
Signed informed consent
Exclusion Criteria:
Significant coronary artery disease
End-stage heart failure (Stage D)
Ischemic cardiomyopathy
Severe systemic hypertension
Primary moderate or severe valvular lesions
Inadequate echocardiographic window
Persistent atrial fibrillation or flutter
BMI <18 kg/m² or alcohol consumption >80 g/day
Life expectancy <1 year due to other conditions
Study Arms:
Cross-sectional Group:
Group 1: CCM patients with ICD (high-risk group)
Group 2: CCM patients without ICD
Longitudinal Group:
All patients followed for outcomes.
Statistical Analysis:
Normality of quantitative variables will be tested using the Kolmogorov-Smirnov test.
Differences between groups analyzed using t-tests, Mann-Whitney tests, chi-square tests, or Fisher's exact tests.
Multivariable Cox proportional hazards models will assess predictors of high-risk outcomes.
Kaplan-Meier survival analysis will estimate event-free survival rates.
Sponsor and Collaborators:
Sponsor: Institute of Cardiology, Federal District, Brazil
Collaborators:
Heart Institute (InCor) - University of São Paulo
Santa Lúcia South Hospital
Principal Investigators:
Dr. Luiz Carlos Madruga Ribeiro
Dr. Ludhmila Abrahão Hajjar
Dr. Adenalva Lima de Souza Beck
Funding Source:
Self-funded (Estimated total cost: BRL 8,200)
Ethical Considerations:
Approved by the ethics committee of ICDF.
Confidentiality and participant safety are prioritized.
Echocardiograms performed by trained physicians.
Inclusion Criteria:
Exclusion Criteria: