Recommended follow-up is dictated by the clinical course of the individual patient. Patients who exhibit only mild symptoms with prompt resolution of symptoms should be followed closely initially, but monitoring can be quickly spaced out to annual visits unless symptoms recur. However, patient with persistent left ventricular (LV) dysfunction or evidence of progression of myocardial inflammation warrant regular follow-up at least every few months or sooner until the patient is stable clinically.[58]Bozkurt B, Colvin M, Cook J, et al. Current diagnostic and treatment strategies for specific dilated cardiomyopathies: a scientific statement from the American Heart Association. Circulation. 2016 Nov 3;134(23):e579-646.
https://www.ahajournals.org/doi/full/10.1161/CIR.0000000000000455
http://www.ncbi.nlm.nih.gov/pubmed/27832612?tool=bestpractice.com
[79]Howlett JG, McKelvie RS, Arnold JM, et al. Canadian Cardiovascular Society Consensus Conference guidelines on heart failure, update 2009: diagnosis and management of right-sided heart failure, myocarditis, device therapy and recent important clinical trials. Can J Cardiol. 2009 Feb;25(2):85-105.
https://www.ccs.ca/images/Guidelines/Guidelines_POS_Library/HF_CC_2009.pdf
http://www.ncbi.nlm.nih.gov/pubmed/19214293?tool=bestpractice.com
In children, biopsy or cardiac MRI may be necessary if ventricular function, inflammatory biomarkers, or viral activity continue to be abnormal at follow-up.[15]Law YM, Lal AK, Chen S, et al. Diagnosis and management of myocarditis in children: a scientific statement from the American Heart Association. Circulation. 2021 Aug 10;144(6):e123-35.
https://www.ahajournals.org/doi/full/10.1161/CIR.0000000000001001
http://www.ncbi.nlm.nih.gov/pubmed/34229446?tool=bestpractice.com
For adults, the American College of Cardiology (ACC) recommends:[56]Writing Committee, Drazner MH, Bozkurt B, et al. 2024 ACC Expert Consensus Decision Pathway on strategies and criteria for the diagnosis and management of myocarditis: a report of the American College of Cardiology Solution Set Oversight Committee. J Am Coll Cardiol. 2025 Feb 4;85(4):391-431.
https://www.jacc.org/doi/10.1016/j.jacc.2024.10.080
http://www.ncbi.nlm.nih.gov/pubmed/39665703?tool=bestpractice.com
Echocardiogram should include assessment of strain if possible. For adults with symptomatic heart failure with reduced ejection fraction, the initial follow-up visit should ideally occur within 1 week, and additional interval visits may be necessary for titration of therapy.[56]Writing Committee, Drazner MH, Bozkurt B, et al. 2024 ACC Expert Consensus Decision Pathway on strategies and criteria for the diagnosis and management of myocarditis: a report of the American College of Cardiology Solution Set Oversight Committee. J Am Coll Cardiol. 2025 Feb 4;85(4):391-431.
https://www.jacc.org/doi/10.1016/j.jacc.2024.10.080
http://www.ncbi.nlm.nih.gov/pubmed/39665703?tool=bestpractice.com
Assessment for return to competitive sports and high-intensity exercise:
This is usually done 6 months after diagnosis, but it may be considered after 3 months for some athletes.[56]Writing Committee, Drazner MH, Bozkurt B, et al. 2024 ACC Expert Consensus Decision Pathway on strategies and criteria for the diagnosis and management of myocarditis: a report of the American College of Cardiology Solution Set Oversight Committee. J Am Coll Cardiol. 2025 Feb 4;85(4):391-431.
https://www.jacc.org/doi/10.1016/j.jacc.2024.10.080
http://www.ncbi.nlm.nih.gov/pubmed/39665703?tool=bestpractice.com
For adults, the ACC recommends follow-up cardiac MRI, 24-hour monitoring for arrhythmia, and exercise stress testing.[56]Writing Committee, Drazner MH, Bozkurt B, et al. 2024 ACC Expert Consensus Decision Pathway on strategies and criteria for the diagnosis and management of myocarditis: a report of the American College of Cardiology Solution Set Oversight Committee. J Am Coll Cardiol. 2025 Feb 4;85(4):391-431.
https://www.jacc.org/doi/10.1016/j.jacc.2024.10.080
http://www.ncbi.nlm.nih.gov/pubmed/39665703?tool=bestpractice.com
Transthoracic echocardiography may be considered instead of cardiac MRI for low-risk patients.[56]Writing Committee, Drazner MH, Bozkurt B, et al. 2024 ACC Expert Consensus Decision Pathway on strategies and criteria for the diagnosis and management of myocarditis: a report of the American College of Cardiology Solution Set Oversight Committee. J Am Coll Cardiol. 2025 Feb 4;85(4):391-431.
https://www.jacc.org/doi/10.1016/j.jacc.2024.10.080
http://www.ncbi.nlm.nih.gov/pubmed/39665703?tool=bestpractice.com
Similarly, for children, the American Heart Association recommends normalisation of inflammatory and myocardial injury markers, normalisation of ventricular function and heart failure, 24-hour Holter monitoring, and exercise stress testing before return to competitive sports.[15]Law YM, Lal AK, Chen S, et al. Diagnosis and management of myocarditis in children: a scientific statement from the American Heart Association. Circulation. 2021 Aug 10;144(6):e123-35.
https://www.ahajournals.org/doi/full/10.1161/CIR.0000000000001001
http://www.ncbi.nlm.nih.gov/pubmed/34229446?tool=bestpractice.com
If all of these tests are normal and the patient displays no symptoms, return to strenuous exercise and competitive sports is permitted. However, athletes should continue to have periodic reassessment to monitor for recurrence and silent clinical progression, particularly within the first 2 years.[56]Writing Committee, Drazner MH, Bozkurt B, et al. 2024 ACC Expert Consensus Decision Pathway on strategies and criteria for the diagnosis and management of myocarditis: a report of the American College of Cardiology Solution Set Oversight Committee. J Am Coll Cardiol. 2025 Feb 4;85(4):391-431.
https://www.jacc.org/doi/10.1016/j.jacc.2024.10.080
http://www.ncbi.nlm.nih.gov/pubmed/39665703?tool=bestpractice.com