Why some viral infections trigger permanent heart damage—and how to spot it early
A new review identifies the mechanisms that cause certain viruses to destroy heart muscle and trigger lifelong heart failure. The finding matters because doctors currently struggle to predict which patients will develop chronic cardiac damage after viral infection, and pharmaceutical companies are now targeting the immune pathways that drive persistent inflammation.
Originaltitel: Post-viral myocarditis.
Viral myokarditer utvecklas ofta till dilaterande kardiomyopati och hjärtsvikt — en progression som kräver tidigare identifiering och riktad behandling för att minska patientöverföring till transplantationslistan. Parvovirus B19, humant herpesvirus 6 och enteroviruses orsakar akut myokardinflammation som kan bli kronisk. Forskare från Wroclaw Medical University och Karolinska Institutet kartlägger hur viral persistens och oreglerad immunaktivering driver långsiktig myokardskada trots minimal virusreplikation. Patofysiologin omfattar tre överlappande faser: virusingång, immunaktivering och ombyggnad av ventrikelvägg. Inflammasom-aktivering och autoimmuna svar framkallar fibros och dysfunktion. Klassisk diagnostik kombinerar biomarkörer, kardial magnetresonans och endomyokardbiops — men behandlingen förblir huvudsakligen stödjande. Inköpschefer bör följa utveckling av immunmodulerande läkemedel. Regulatoriska aktörer måste förbättra vägar för tidiga prognostiska tester för att identifiera patienter med högt progressionsrisk innan irreversibel ventrikelskada uppstår.
Myocarditis is an inflammatory disease of the myocardium characterized by complex histological, immunological and molecular changes occur that may ultimately lead to post-viral cardiomyopathy, a specific phenotype of dilated cardiomyopathy and heart failure (HF) after a viral infection. Viral infections remain a major cause, with pathogens like parvovirus B19, human herpesvirus 6, and enteroviruses frequently associated with both acute myocarditis and its progression to chronic myocardial dysfunction. This review aims to provide an overview of the mechanisms linking viral myocarditis to the development of dilated cardiomyopathy and HF, with emphasis on factors contributing to disease persistence, progression, and current diagnostic approaches. Progression of myocarditis reflects overlapping phases of viral entry, immune activation, and remodeling. While direct cytotoxic effects contribute to early myocardial injury, ongoing damage is primarily driven by persistent immune activation, often despite limited viral replication. Viral persistence, dysregulated interferon signaling, inflammasome activation, and autoimmune responses sustain myocardial inflammation, promoting fibrosis and ventricular dysfunction. These processes are further reinforced by neurohormonal and metabolic changes, leading to adverse remodeling. Clinically, myocarditis presents with a broad spectrum ranging from mild symptoms to fulminant HF and malignant arrhythmias. Diagnosis relies on biomarkers, cardiac magnetic resonance, and endomyocardial biopsy to assess myocardial injury and detect viral presence. Management remains mainly supportive, with limited and inconsistent evidence for targeted immunomodulatory or antiviral therapies. In conclusion, improved understanding of the interplay between viral persistence and immune-mediated injury is essential for identifying patients at risk of progression and for developing mechanism-based therapeutic strategies.