Investigating the Short‐Term Changes of the Electrocardiogram Indicators During Hospitalization in Patients With COVID‐19 Following the Use of Tocilizumab

OBJECTIVES: To evaluate short-term changes in electrocardiographic (ECG) parameters after tocilizumab administration in COVID-19 patients, considering the drug's role in treating severe cases and the involvement of IL-6 in cardiovascular effects and ECG alterations. METHODS: In this retrospective study, we assessed cardiovascular and electrocardiographic parameters in PCR-confirmed COVID-19 patients who received tocilizumab. ECG variables were evaluated at two time points: 24 h before and 24 h after drug administration. All ECGs were verified by a supervisor, and demographic information was extracted from patient records. RESULTS: 33 patients were included, of whom 36.4% were men. The patients' ages ranged from 37 to 79 years. The corrected QT interval (QTc) measured 24 h before (QTc1) and 24 h after (QTc2) tocilizumab administration showed no significant difference (QTc1: 390.3 ± 31.67 ms; QTc2: 392.73 ± 36.68 ms). No significant ECG changes were observed in the ST segment, ventricular fibrillation (VF), ventricular tachycardia (VT), or atrial fibrillation (AF). Four patients experienced cardiorespiratory arrest within 24 h after receiving tocilizumab. CONCLUSION: Tocilizumab administration in critically ill COVID-19 patients was not associated with significant short-term ECG changes or specific cardiovascular complications. Although previous studies in inflammatory diseases such as rheumatoid arthritis have reported QTc shortening following tocilizumab treatment, likely through suppression of IL-6-mediated systemic inflammation, no significant QTc reduction was observed in our cohort during the 24-h follow-up period. A few cases of cardiorespiratory arrest occurred; a causal relationship with tocilizumab could not be established due to the severity of illness and limited clinical data.