COVID-19 mRNA vaccinations have recently been implicated in causing
myocarditis. Therefore, the primary aim of this systematic review and meta-analysis was to investigate the clinical characteristics of patients with
myocarditis following
mRNA vaccination. The secondary aims were to report common imaging and laboratory findings, as well as treatment regimes, in these patients. A literature search was performed from December 2019 to June 2022. Eligible studies reported patients older than 18 years vaccinated with
mRNA, a diagnosis of
myocarditis, and subsequent outcomes. Pooled mean or proportion were analyzed using a random-effects model. Seventy-five unique studies (patient n = 188, 89.4% male, mean age 18-67 years) were included. Eighty-six patients had Moderna
vaccines while one hundred and two patients had Pfizer-BioNTech
vaccines. The most common presenting symptoms were
chest pain (34.5%),
fever (17.1%),
myalgia (12.4%), and
chills (12.1%). The most common radiologic findings were ST-related changes on an electrocardiogram (58.7%) and
hypokinesia on cardiac magnetic resonance imaging or echocardiography (50.7%). Laboratory findings included elevated
Troponin I levels (81.7%) and elevated
C-reactive protein (71.5%). Seven patients were admitted to the intensive care unit. The most common treatment modality was non-
steroid anti-inflammatory drugs (36.6%) followed by
colchicine (28.5%). This meta-analysis presents novel evidence to suggest possible
myocarditis post
mRNA vaccination in certain individuals, especially young male patients. Clinical practice must therefore take appropriate pre-cautionary measures when administrating
COVID-19 mRNA vaccinations.