COVID-19 vaccine-induced acute myocarditis: case report

Abstract

Introduction: Myocarditis is the progressive inflammation of the middle layer of the heart followed by a myocardium injury without ischemic events. Causes of myocarditis can either be infectious or non infectious. One of the causes of non-infectious myocarditis is myocarditis as an adverse reaction to the vaccine. In late December 2020 COVID-19 vaccination began in Lithuania with mRNA vaccines by Pfizer-BioNTech and Moderna, Janssen vaccine was brought more recently in April 2021. Immunization against COVID-19 and other viral pathogens using mRNA-based vaccines is a new and promising technology. In the clinical trials, systemic adverse reactions after the second dose were reported mainly in the younger male population with a median onset time of one to two days. Case report: A 19-year-old previously healthy male arrived at the emergency department presented with a chief complaint of non-radiating chest pain of 3 days duration. He reported pressure-like, dull pain, 8-9/10 intensity, not relieved by non-steroidal anti-inflammatory drugs or paracetamol. He reported receiving the second dose of the COVID-19 Janssen vaccine 4 days before the symptoms. Soon after the vaccination, he had a fever up to 39°C that lasted for three days; the day after chest pain occurred. He had no previous history of viral illnesses and no known COVID-19 exposure. ECG demonstrated SR, HR 80 bpm, ST elevation in the precordial leads without reciprocal changes. CRP was 43,78 mg/l (normal 0-5 mg/l), troponin T 535,6 ng/l (normal 0-14 ng/l), and BNP 74,2 ng/l (normal 0-26,5 ng/l) thus he was transferred to University hospital for a cardiologist evaluation. The laboratory testing showed high troponin I levels, which was 9,12 g/l (normal 0-0,04 g/l); bedside echocardiography revealed hypokinetic posterior and inferior walls of the left ventricle. Coronary angiography showed no signs of stenosis. The myocarditis was suspected and the patient was admitted to the Department of Cardiology. The cardiac MRI areas with elevated signal intensity in T2 sequence indicating oedema, late gadolinium accumulation and signs of acute myocardial injury subepicardial. No signs of significant arrhythmias or conduction disturbances were registered. An echocardiogram, which had been done on day 3 after admission, demonstrated dilated left ventricle (LV), poor contraction of inferior, posterior, lateral walls. The patient received intravenous ketorolac 30 mg p.r.n for pain. Troponin level decreased 50% over the first two 48 hours and almost reached a normal level (0,06 g/l) on the day of discharge. He was discharged on hospital day 6 based on improved symptoms, declined troponin level. The patient had not yet returned for a follow-up visit at the time of this submission. Conclusions: Although rare, clinicians should be aware of the possibility of myocarditis, which should be taken into account in patients who report chest pain within a week of vaccination, particularly in the younger population.