MedWire News: The use of point-of-care (POC) coagumeters speeds the assessment of international normalized ratio (INR) in patients with acute stroke and on oral anticoagulation (OAC), a clinical study has found.
The study authors say that POC testing, as an alternative to time-consuming testing in central laboratories, may hasten the initiation of thrombolytic therapy in eligible individuals.
The emergency management of stroke in patients on OAC poses a particular challenge, explain Roland Veltkamp (University Heidelberg, Germany) and fellow researchers. An elevated INR is generally considered a contraindication to thrombolysis, yet many patients on OAC have subtherapeutic INRs; thus, INR testing is mandatory all OAC patients before initiating thrombolytic therapy.
In this two-phase, prospective, observational study, Veltkamp and team assessed the accuracy and effectiveness of a POC device for measuring INR in the emergency setting.
In phase one, the team studied 113 individuals on OAC presenting to hospital with acute stroke. INRs were assessed using a POC coagumeter device and by standard central laboratory testing.
Bland-Altman analysis indicated close agreement between the two INR assays (mean deviation of paired differences=0.02) and Pearson correlation score was highly significant, with an r-value of 0.98.
In phase two, the researchers studied 48 patients with acute stroke and presenting within the timeframe for systemic thrombolysis. In all, 34 patients were on OAC and 23 ultimately received intravenous thrombolytic therapy.
A comparison of INR results again indicated close agreement and a highly significant correlation between bedside and laboratory values. Furthermore, INRs obtained by POC testing were available 28 minutes earlier, on average, than INRs obtained from the central laboratory.
This represents a “drastic” reduction in the time interval until INR values are available, say the authors, and may therefore hasten initiation of thrombolysis.
They add: “Besides rapidly identifying stroke patients who could receive thrombolysis despite the fact that they are currently using OAC… instant POC measurements of INR levels that prohibit systemic thrombolysis can help to guide the diagnostic work-up and subsequent therapeutic procedures at an early stage.”
The results of this study are published in the journal Stroke.
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