Predictability of CRP and D-Dimer levels for in-hospital outcomes and mortality of COVID-19

Background: Systemic inflammation elicited by a cytokine storm is considered a hallmark of coronavirus disease 2019 (COVID-19). This study aims to assess the clinical utility of the C-reactive protein (CRP) and D-Dimer levels for predicting in-hospital outcomes in COVID-19. Methods: A retrospective cohort study was performed to determine the association of CRP and D-Dimer with the need for invasive mechanical ventilation (IMV), dialysis, upgrade to an intensive care unit (ICU) and mortality. Independent t-test and multivariate logistic regression analysis were performed to calculate mean differences and adjusted odds ratios (aOR) with its 95% confidence interval (CI), respectively. Results: A total of 176 patients with confirmed COVID-19 diagnosis were included. On presentation, the unadjusted odds for the need of IMV (OR 2.5, 95% CI 1.3-4.8, p = 0.012) and upgrade to ICU (OR 3.2, 95% CI 1.6-6.5, p = 0.002) were significantly higher for patients with CRP (>101 mg/dl). Similarly, the unadjusted odds of in-hospital mortality were significantly higher in patients with high CRP (>101 mg/dl) and high D-Dimer (>501 ng/ml), compared to corresponding low CRP (<100 mg/dl) and low D-Dimer (<500 ng/ml) groups on day-7 (OR 3.5, 95% CI 1.2-10.5, p = 0.03 and OR 10.0, 95% CI 1.2-77.9, p = 0.02), respectively. Both high D-Dimer (>501 ng/ml) and high CRP (>101 mg/dl) were associated with increased need for upgrade to the ICU and higher requirement for IMV on day-7 of hospitalization. A multivariate regression model mirrored the overall unadjusted trends except that adjusted odds for IMV were high in the high CRP group on day 7 (aOR 2.5, 95% CI 1.05-6.0, p = 0.04). Conclusion: CRP value greater than 100 mg/dL and D-dimer levels higher than 500 ng/ml during hospitalization might predict higher odds of in-hospital mortality. Higher levels at presentation might indicate impending clinical deterioration and the need for IMV.