Precipitating factors of bradycardia after remdesivir administration: ICU admission and cutoff value for declining heart rate

Despite increasing concerns about the association between remdesivir and bradycardia in severe coronavirus disease 2019 (COVID-19) patients receiving remdesivir, information on its clinical course and precipitating factors is limited. Our aim was to investigate possible triggers of bradycardia after remdesivir administration. We retrieved the medical records of hospitalized severe and critical COVID-19 patients who received remdesivir from May 1, 2021 to June 30, 2021. Bradycardia was defined as two episodes of a heart rate (HR) < 60 bpm in 24 hours. Receiver operating characteristic (ROC) curve analysis was conducted to evaluate the discriminability of heart rate pattern on the occurrence of bradycardia. The precipitating factors of bradycardia were examined by a logistic regression model. Regardless of bradycardia status, the median heart rate dropped during remdesivir treatment (from 85 to 72 bpm, p<0.001), with the heart rate dropping considerably within the first two days of remdesivir treatment. Among various heart rate descriptors, HR ratiomin (d2-d1) had the best discrimination (AUC=0.7336), and a reduction in HR ratiomin (d2-d1) by 14.65% was associated with bradycardia. Intensive care unit (ICU) admission was associated with an increased risk of bradycardia (odds ratio: 3.41; 95% CI: 1.12-10.41). In severe COVID-19 patients receiving remdesivir, the risks of bradycardia were influenced by a substantial reduction in heart rate during the first two days of remdesivir treatment and ICU admission. These findings suggest that clinical practitioners should intensively monitor heart rates during remdesivir treatment.