Point-of-Care Device for Assessment of Blood Coagulation Status in COVID-19 Patients

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent driving the current COVID-19 pandemic. The acute respiratory distress that occurs in some severe COVID-19 cases has been linked with hypercoagulation or thrombotic events as well as a worse prognosis and increased risk of death. Thus, point-of-care devices that can be used for early detection of coagulation abnormalities would assist in COVID-19 management. This chapter describes the use of the Roche Diagnostics CoaguChek^® XS test kit for potential use in COVID-19 personalized medicine approaches.

Point-of-care testing of coagulation in patients treated with edoxaban

Edoxaban, alongside other direct oral anticoagulants (DOAC), is increasingly used for prevention of thromboembolism, including stroke. Despite DOAC therapy, however, annual stroke rate in patients with atrial fibrillation remains 1–2%. Rapid exclusion of relevant anticoagulation is necessary to guide thrombolysis or reversal therapy but, so far, no data exists on the effect of edoxaban on available point-of-care test systems (POCT). To complete our previous investigation on global coagulation-POCT for the detection of DOAC, we evaluated whether CoaguChek®-INR (CC-INR) is capable of safely ruling out edoxaban concentrations above the current treatment thresholds of 30/50 ng/mL in a blood sample. We studied patients receiving a first dose of edoxaban; excluding subjects receiving other anticoagulants. Six blood samples were collected from each patient: before drug intake, 0.5, 1, 2 and 8 h after intake, and at trough (24 h). CC-INR and mass spectrometry for edoxaban concentrations were performed for each time-point. One hundred and twenty blood samples from 20 patients contained 0–302 ng/mL of edoxaban. CC-INR ranged from 0.9 to 2.3. Pearson’s correlation coefficient showed strong correlation between CC-INR and edoxaban concentrations (r = 0.73, p < 0.001). Edoxaban concentrations > 30 and > 50 ng/mL were ruled out by CC-INR ≤ 1.0 and ≤ 1.1, respectively, with high specificity (> 95%), and a sensitivity of 44% (95%-confidence interval: 30–59%) and 86% (74–93%), respectively. Our study represents the first evaluation of coagulation-POCT in edoxaban-treated patients. CC-POCT is suitable to safely exclude clinically relevant edoxaban concentrations prior to thrombolysis, or guide reversal therapy in stroke patients.

Assessment of point-of-care measurement of international normalised ratio using the CoaguChek XS Plus system in the setting of acute ischaemic stroke

BACKGROUND AND AIMS

Thrombolysis with alteplase (recombinant tissue plasminogen activator) is accepted hyperacute therapy for acute ischaemic stroke. Clotting must be normal before this can be administered safely. Laboratory testing of international normalised ratio (INR) takes 30-60 min, which can significantly delay administration of recombinant tissue plasminogen activator. Previous studies have suggested that point-of-care testing is useful in patients presenting with stroke and improves door-to-needle time. We performed a prospective study of point-of-care testing in patients presenting with acute ischaemic stroke.

METHODS

Fifty patients were entered into the study to compare point-of-care testing using the CoaguChek XS system with laboratory testing of INR.

RESULTS

Point-of-care testing correlated well with laboratory levels (R = 0.93, P < 0.0001). The standard deviation of difference between the two was 0.115. Overall, point-of-care testing tended to underestimate INR slightly, meaning that an INR value of 1.1 or less was required to be 95% certain that the laboratory value was 1.3 or below. Simultaneous testing using blood from a syringe was more consistent with laboratory results than testing capillary blood through finger prick.

CONCLUSION

Point-of-care INR testing correlates well with laboratory values. The results in this study mostly relate to values in the normal range. We suggest that it can be used to try to shorten door-to-needle time.