Remdesivir-induced bradycardia in patients hospitalized with SARS-CoV2 infection: a possible vagally-mediated mechanism.

Recently, case series studies on patients with SARS-CoV-2 infection reported an association between remdesivir (RDV) administration and incidental bradycardia. However, the phenomenon has not yet been described in detail. We conducted a retrospective case-control study to evaluate the occurrence of RDV-related bradycardia in patients hospitalized for SARS-CoV2 pneumoniae. We retrospectively evaluated 71 patients, hospitalized in six internal medicine wards of the Milan area, affected by mild-to-moderate COVID-19 who received RDV (RDV group) and 54 controls, matched for sex, age and disease severity on admission (CTR group). The mean heart rate value recorded during the first two days of hospitalization was considered as baseline heart rate (HRb). Heart rate values relative to the 5-days treatment and the 5-days post-treatment were extracted for RDV group, while heart rate values relative to 10 days of hospitalization were considered for the CTR group. ΔHR values were calculated as maximum HR drop versus HRb. Possible associations between ΔHR and clinical-demographic factors were assessed through regression analysis. The RDV group experienced a significantly higher incidence of bradycardia compared to the CTR group (56% vs 33%, OR 2.6, 95% CI 1.2-5.4, p value = 0.011). Moreover, the RDV group showed higher ΔHR values than the CTR group. The HR progressively decreased with daily administration of RDV, reaching the maximun drop on day six (-8.6±1.9 bpm). In RDV group, patients who experienced bradycardia had higher drop in HR, higher alanine aminotransferase (ALT) values at the baseline (bALT) and during the RDV administration period. ΔHR was positively associated with HRb (β = 0.772, p < 0.001) and bALT (β = 0.245, p = 0.005). In conclusion, our results confirmed a significant association between RDV administration and development of bradycardia. This effect was proportional to baseline HR and was associated with higher levels of baseline ALT, suggesting a possible interaction between RDV liver metabolism and a vagally-mediated effect on HR due to increased availability of RDV metabolites.