Biomarker of Covid Pneumonia vs Congestive Heart Failure: A Key to Disease Diagnosis

Abstract

The SARS-CoV2 virus is known to cause atypical pneumonia, but in this uncertain time with a lack of sensitive testing, laboratory values such as inflammatory markers, procalcitonin, and brain natriuretic peptide (BNP) may suggest a diagnosis of COVID-19 pneumonia, bacterial pneumonia, or CHF exacerbation. Commonly, the patients with respiratory symptoms, bilateral infiltrates on imaging and a negative COVID-19 nasopharyngeal swab test have been continued to be isolated with suspicion of having COVID-19 pneumonia. There is still a lack of significant research, that evaluates the benefits of biomarkers towards getting a definite diagnosis. We conducted a prospective study to analyse the difference in clinical markers in COVID positive patients compared to COVID-19 negative patients with respiratory symptoms and bilateral infiltrates on imaging, to get a better understanding of characteristics that may help differentiate COVID-19 pneumonia from bacterial pneumonia or CHF on admission. METHODS: We conducted a prospective observational single health center study. Inclusion criteria were patients who were admitted to our hospital with confirmed COVID-19 testing by nasopharyngeal swab (Confirmed group) or COVID-19 negative patients with respiratory symptoms and bilateral infiltrates on imaging (High Suspicion group). Lab markers measured on these patients were ferritin, procalcitonin, BNP, and CRP. RESULTS: Out of 100 patients analyzed to have suspected pneumonia, 26 were in the Confirmed group, 74 were in the High suspicion group. 0% COVID positive patients had a history of CHF, whereas 20.2% of those High suspicion group had a h/o CHF. The Confirmed group had a Procalcitonin >0.2 in 42.8%, BNP $800 in 23%, Ferritin $800 in 45.5%, and CRP >4 in 69.5%. The High suspicion group had Procalcitonin >0.2 in 28.4% and BNP $800 in 40.5%. CONCLUSIONS: Many studies discussed a biomarker-based test to distinguish between bacterial and viral etiologies of pneumonia with sufficient accuracy and specificity for clinical. Based on our data there appears to be an importance of initial lab testing and thorough clinical examination to narrow down differentials between CHF, COVID pneumonia, and bacterial pneumonia. Procalcitonin, for example, was more elevated in the COVID group. We found that many patients in the High Suspicion group were empirically treated as COVID patients and isolated as such. Through more studies, developing a biomarker scoring system may help diagnose COVID pneumonia. CLINICAL IMPLICATIONS: Currently, there are no biomarker-based algorithms for establishing the etiology of pneumonia. Further studies are required to explore a combination of biomarkers and symptoms for use as a definitive diagnostic tool for COVID patients.