Dear Editor

We would like to share ideas on the publication “CMR Imaging 6 Months After Myocarditis Associated with the BNT162b2 mRNA COVID-19 Vaccine [1].” Amir et al. noted that “PCVM is a rare complication, affecting predominantly males and appearing usually within the first week after administration of the second dose of the ….. Late CMR follow-up demonstrated resolution of the edema in all patients, while some had evidence of residual myocardial scarring [1].” We agree that COVID vaccination might induce clinical complication including cardiac problem. The etiology of thrombosis is unknown but it is believed to be due to abnormal immune/inflammatory response or increased blood viscosity [2]. The current study can confirm the mild nature of the vaccine-associated myocarditis and can reconfirm that the rapid increased blood viscosity/immune response after vaccination should be the cause of cardiac abnormality. When time passes, the immune response will decline and viscosity decreased which is concordant with the recovery from the mild cardiac problem.