Subacute Effects of Vaccination with a Messenger RNA-based Vaccine Against Coronavirus Disease 2019 on Elderly Japanese Patients with Cardiac Disorder

The present observational study assessed the occurrence of adverse cardiac events following vaccination of patients (n = 100) with an mRNA-based vaccine against coronavirus disease 2019 (COVID-19). Death and deterioration of heart failure were evaluated as side effects. The status of heart failure was assessed using the brain natriuretic peptide (BNP) ratio, for which the BNP or NT-pro BNP values were divided by their upper normal limits (UNL); values (i.e., post-BNP levels minus pre-BNP levels) ≥ 10-fold higher than the UNL denoted significant increment. Here we show that vaccination with an mRNA-based vaccine against COVID-19 was associated with a high risk of death or decompensated heart failure for elderly patients with a BNP ratio ≥ 4-fold higher than the UNL. Six and 15 patients expired and exhibited significant increment of the BNP ratio, respectively; these patients had a pre-BNP ratio ≥ 4-fold higher than the UNL. Forty-five patients with a pre-BNP ratio < 4-fold higher than the UNL did not expire or show significant increase in the BNP ratio. The pre-BNP ratio was a reliable parameter for predicting cardiac deterioration after vaccination. For the booster or initial vaccination against COVID-19, the BNP ratio may be useful in assessing the cardiac status of elderly patients.