Insights Into the Natural History of Recurrent Myocarditis, A Multicenter International Study (Re-Myo Study)
Acute myocarditis is an inflammation of the heart muscle that can cause chest pain, shortness of breath, palpitations, or, in some cases, more severe complications. While many people experience only one episode, some develop recurrent acute myocarditis, meaning that the inflammation returns after an initial recovery. Until now, little has been known about the long-term consequences of these recurrent episodes.
To better understand this condition, researchers from 14 international centers studied more than 500 patients with acute myocarditis, comparing those who experienced recurrent episodes (141 patients) with those who had only a single episode (372 patients). This is one of the largest studies to investigate recurrent acute myocarditis.
The study showed that patients with recurrent myocarditis were more likely to have a family history of cardiomyopathy, autoimmune diseases, and certain patterns of heart scarring on cardiac magnetic resonance imaging (MRI). Genetic testing, when performed, frequently identified disease-causing variants, particularly in genes linked to inherited heart muscle diseases such as desmoplakin (DSP) and filamin C (FLNC).
Although the first episode often appeared similar in both groups, repeated episodes were associated with a gradual increase in heart scarring over time. This was accompanied by a higher risk of developing serious heart rhythm disturbances (ventricular arrhythmias), which may increase the likelihood of life-threatening sudden cardiac events. Overall, patients with recurrent myocarditis had a less favorable long-term prognosis than those with a single episode.
These findings highlight the importance of careful follow-up after an episode of myocarditis, especially in people with a family history of heart disease, autoimmune disorders, or specific MRI findings. In selected patients, additional investigations, including genetic testing and, in some cases, heart biopsy, may help identify the underlying cause and guide personalized treatment.
By improving the identification of patients at higher risk, this study may help physicians provide closer monitoring and develop more individualized management strategies for people living with recurrent acute myocarditis.
Baggio C, Cannata A, Gasperetti A, Ammirati E, Gentile P, Peretto G, Savonitto G, Cecere A, Collini V, Sikking M, Mistrulli R, Pagannone E, Rossi VA, Schmidt D, Compagnucci P, Casella M, Artico J, Ciabatti M, Fabris E, Perazzolo Marra M, Pieroni M, Bromage DI, Scott PA, Saguner AM, Verdonschot JAJ, Mohiddin S, Calo L, Imazio M, Heymans S, Sinagra G, Merlo M; Member of ERN Guard Heart Network. Insights Into the Natural History of Recurrent Myocarditis, A Multicenter International Study (Re-Myo Study). J Am Heart Assoc. 2026 May 19;15(10):e046767. doi: 10.1161/JAHA.125.046767. Epub 2026 May 6. PMID: 42089151.
Natural History and Clinical Impact of Recurrent Acute Myocarditis
Prepared by Marco Merlo and Ruth Biller