Prospective cohort study of TIMP-1 and myocardial fibrosis in Chagas disease at a reference clinic in Pernambuco, Brazil: PTICH trial protocol

BACKGROUND: Chagas disease affects millions of individuals across Latin America and imposes a substantial economic burden on healthcare systems, particularly in rural and underserved regions. Chronic Chagasic cardiomyopathy remains one of the leading causes of heart failure-related mortality in endemic countries. Tissue inhibitor of metalloproteinases-1 (TIMP-1) has emerged as a potential biomarker of myocardial fibrosis in cardiomyopathies. This study was designed to investigate the association between TIMP-1 and myocardial fibrosis in chronic Chagas disease and to assess its potential as an early biomarker of fibrotic remodelling. METHODS AND ANALYSIS: Bottom of form: The PTICH trial is a single-centre, prospective observational cohort study conducted at a government reference clinic in Pernambuco, Brazil. The study aims to enrol 210 adults with Chagas heart disease: 140 without ventricular dysfunction (left ventricular ejection fraction (LVEF) ≥52% in women and ≥54% in men) and 70 with ventricular dysfunction (LVEF <52% in women or <54% in men, or previously reduced LVEF with subsequent improvement). Participants' assessments occur at baseline and at 18 months (±3 months), including clinical evaluation; transthoracic echocardiography (LVEF and global longitudinal strain); cardiac magnetic resonance imaging (CMR) with late gadolinium enhancement quantified as a percentage of left ventricular myocardial mass and parametric mapping (native T1 and extracellular volume fraction), when available; and laboratory testing (plasma TIMP-1 and N-terminal pro-B-type natriuretic peptide). Blood samples will be processed to plasma and stored at -80°C. The primary outcome is the change in plasma TIMP-1 levels from baseline to 18 months and its correlation with CMR-assessed myocardial fibrosis. Statistical analyses will estimate within-participant changes using paired tests with 95% CIs and evaluate associations using correlation analyses and multivariable linear regression adjusted for age, sex and ejection fraction strata. ETHICS AND DISSEMINATION: The Research Ethics Committee (REC) of Chagas disease and heart failure outpatient clinic-PROCAPE approved the PTICH trial (CAAE number: 65746322.8.1001.5192). Written informed consent has been obtained from all participants enrolled to date, and data handling is in compliance with applicable privacy and data protection regulations. Study findings will be disseminated through targeted outreach to civil society, the scientific community, healthcare professionals and Brazilian Unified Health System (SUS) policymakers; school-based science communication activities conducted in collaboration with state education departments (potentially including oral health educational materials); policy briefs and targeted reports for public health managers; technical meetings and institutional presentations; a plain-language summary published on the institutional website; and submissions to peer-reviewed journals and presentations at academic and health policy conferences. TRIAL REGISTRATION NUMBER: RBR-3dcrj98.