Haematological parameters predicting cardiac involvement in children with COVID-19 infection

Haematological parameters obtained from the full blood count, such as neutrophil-to-lymphocyte ratio (NLR), are cost-effective tests which have been shown to be predictive of the prognosis of many diseases. We aimed to evaluate certain haematological parameters and cardiac biomarkers to test whether they could predict cardiac involvement by COVID-19 infection.

This retrospective study included patients aged 1 month to 18 years having a positive COVID-19 PCR test but no comorbidity, who were admitted to the paediatric emergency department between 15 March 2020 and 1 February 2021.

There were 292 COVID-19 PCR-positive patients, 12 MIS-C patients and 70 healthy controls. A receiver operator characteristic curve analysis was performed to predict MIS-C in patients with COVID-19 infection. An NLR value of ≥5.03 could predict MIS-C with a sensitivity of 66.7% and a specificity of 91.6%; a proBNP value of ≥329.5 ng/L with a sensitivity of 91.7% and a specificity of 95.6%; a CKMB value of ≥2.95 μg/L with a sensitivity of 100% and a specificity of 77.7%; and a troponin-I value of ≥0.03 μg/L with a sensitivity of 75% and a specificity of 99.2%. A logistic regression analysis showed that an NLR value of ≥5.03 increased the risk of MIS-C 19.3 fold; a proBNP value of ≥329.5 ng/L increased the risk 238 fold; and a troponin-I value of ≥0.03 μg/L increased the risk 60 fold.

At the time of admission, parameters such as proBNP, troponin-I and NLR can predict the development of MIS-C in COVID-19 patients with high sensitivity and specificity.