Predicting QT interval prolongation in patients diagnosed with the 2019 novel coronavirus infection

INTRODUCTION: 2019 novel coronavirus (COVID-19) patients frequently develop QT interval prolongation that predisposes them to Torsades de Pointes and sudden cardiac death. Continuous cardiac monitoring has been recommended for any COVID-19 patient with a Tisdale Score of seven or more. This recommendation, however, has not been validated. METHODS: We included 178 COVID-19 patients admitted to a non-intensive care unit setting of a tertiary academic medical center. A receiver operating characteristics curve was plotted to determine the accuracy of the Tisdale Score to predict QT interval prolongation. Multivariable analysis was performed to identify additional predictors. RESULTS: The area under the curve of the Tisdale Score was 0.60 (CI 95%, 0.46-0.75). Using the cutoff of seven to stratify COVID-19, patients had a sensitivity of 85.7% and a specificity of 7.6%. Risk factors independently associated with QT interval prolongation included a history of end-stage renal disease (ESRD) (OR, 6.42; CI 95%, 1.28-32.13), QTc ≥450 ms on admission (OR, 5.90; CI 95%, 1.62-21.50), and serum potassium ≤3.5 mmol/L during hospitalization (OR, 4.97; CI 95%, 1.51-16.36). CONCLUSION: The Tisdale Score is not a useful tool to stratify hospitalized non-critical COVID-19 patients based on their risks of developing QT interval prolongation. Clinicians should initiate continuous cardiac monitoring for patients who present with a history of ESRD, QTc ≥450 ms on admission or serum potassium ≤3.5 mmol/L.