Background: Acute myocarditis has been described as a relatively rare cardiovascular complication of COVID-19 infection. However, data regarding the risk of myocarditis during the post-acute phase of COVID-19 are scant. We assess the risk of incident myocarditis in COVID-19 survivors within one year from the index infection by a systematic review and meta-analysis of the available data.
Methods: Data were obtained searching MEDLINE and Scopus for all studies published at any time up to September 1, 2022, and reporting the long-term risk of incident myocarditis in COVID-19 survivors. Myocarditis risk data were pooled using the Mantel-Haenszel random effects models with Hazard ratio (HR) as the effect measure with 95% confidence interval (CI). Heterogeneity among studies was assessed using Higgins and Thomson I2 statistic.
Results: Overall, 20.875.843 patients (mean age 56.1 years, 59.1% males) were included in this analysis. Of them, 1.245.167 survived to COVID-19 infection. Over a mean follow-up of 9.5 months, myocarditis occurred to 0.21 [95% CI: 0.13- 0.42) out of 1000 patients survived to COVID-19 infection compared to 0.09 [95% CI: 0.07-0.12] out of 1000 control subjects. Pooled analysis revealed that recovered COVID-19 patients presented an increased risk of incident myocarditis (HR: 5.16, 95% CI: 3.87-6.89, p<0.0001, I2=7.9%) within one year from the index infection. The sensitivity analysis confirmed yielded results.
Conclusion: Our findings suggest that myocarditis represents a relatively rare but important post-acute COVID-19 sequelae.
