Understanding acute Myocarditis in Latin America: clinical, imaging, and etiological perspectives from a Colombian multicenter study

Background Acute myocarditis (AM) is an inflammatory disease of the myocardium with a broad spectrum of clinical presentations, diverse etiologies, and variable prognosis. Regional differences in etiological distribution are significant, especially in areas with endemic infectious diseases. However, data from Latin America remain scarce. This study aimed to characterize the clinical, imaging, and etiological features of AM in a Latin American population. Methods We conducted a descriptive, cross-sectional study of adult patients diagnosed with AM at two referral centers in Bogotá, Colombia, between January 2013 and June 2024. Cases were identified through ICD-10 coding and included only if they met the European Society of Cardiology (ESC) diagnostic criteria for suspected or confirmed myocarditis. Clinical, laboratory, electrocardiographic, echocardiographic, and cardiac magnetic resonance imaging (CMR) data were collected. Associations with in-hospital mortality were explored using chi-square testing. Results A total of 205 patients were included (72.1% male; median age 38 years, IQR 29–53). Common comorbidities included hypertension (19.5%), active smoking (15.6%), and obesity (15.6%). Chest pain was the predominant symptom (84.6%), followed by dyspnea (37.6%). CMR was performed in 47.8% of cases, with subepicardial or midwall late gadolinium enhancement observed in 78.6% of those evaluated. An etiological diagnosis could not be established in 71.2% of cases; among identified causes, SARS-CoV-2 infection and Chagas disease were the most frequent. In-hospital complications included pericarditis (28.8%), acute heart failure (15.1%), and fulminant myocarditis (4.9%). The in-hospital mortality rate was 5.39%, and mortality was significantly associated with fulminant presentation (p = 0.031), severe arrhythmias (p = 0.021), and age ≥ 65 years (p = 0.007). Conclusions The clinical and demographic profile of AM in this Latin American cohort is consistent with international data. However, etiological characterization remains limited, reflecting constrained access to advanced diagnostic tools. The presence of tropical infections such as Chagas disease highlights the need for region-specific approaches. Despite diagnostic advances, mortality and complication rates remain substantial.