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

Factors delaying intravenous thrombolytic therapy in acute ischaemic stroke: a systematic review of the literature

BACKGROUND/AIMS

This review examined factors that delay thrombolysis and what management strategies are currently employed to minimise this delay, with the aim of suggesting future directions to overcome bottlenecks in treatment delivery.

METHODS

A systematic review was performed according to PRISMA guidelines. The search strategy included a combination of synonyms and controlled vocabularies from Medical Subject Headings (MeSH) and EmTree covering brain ischemia, cerebrovascular accident, fibrinolytic therapy and Alteplase. The search was conducted using Medline (OVID), Embase (OVID), PubMed and Cochrane Library databases using truncations and Boolean operators. The literature search excluded review articles, trial protocols, opinion pieces and case reports. Inclusion criteria were: (1) The article directly related to thrombolysis in ischaemic stroke, and (2) The article examined at least one factor contributing to delay in thrombolytic therapy.

RESULTS

One hundred and fifty-two studies were included. Pre-hospital factors resulted in the greatest delay to thrombolysis administration. In-hospital factors relating to assessment, imaging and thrombolysis administration also contributed. Long onset-to-needle times were more common in those with atypical, or less severe, symptoms, the elderly, patients from lower socioeconomic backgrounds, and those living alone. Various strategies currently exist to reduce delays. Processes which have achieved the greatest improvements in time to thrombolysis are those which integrate out-of-hospital and in-hospital processes, such as the Helsinki model.

CONCLUSION

Further integrated processes are required to maximise patient benefit from thrombolysis. Expansion of community education to incorporate less common symptoms and provision of alert pagers for patients may provide further reduction in thrombolysis times.

Assessment of agreement and time in therapeutic range of capillary versus venous international normalised ratio in frail elderly people in a nursing home

Vitamin K antagonists are widely used, yet have a slim therapeutic margin and high iatrogenicity. Patients are monitored through international normalised ratio (INR) by venipuncture, but coagulometers could measure INR by capillary puncture. This prospective study evaluated the clinical concordance of capillary INR versus venous INR in 31 nursing home patients. Concordance was good and mean time in therapeutic range (TTR) markedly increased. Capillary INR is thus reliable, could improve TTR and decrease iatrogenicity.

Point-of-care coagulation testing for reducing in-hospital delay in thrombolysis

Background:

The confirmation of prothrombin time international normalized ratio by a central laboratory often delays intravenous thrombolysis in patients with acute ischemic stroke.

Objectives:

We investigated the feasibility, reliability, and usefulness of point-of-care determination of prothrombin time international normalized ratio for stroke thrombolysis.

Methods:

Among 312 patients with ischemic stroke, 202 who arrived at the emergency room within 4.5 h of stroke onset were enrolled in the study. Patients with lost orders for point-of-care testing for the prothrombin time international normalized ratio or central laboratory testing for the prothrombin time international normalized ratio (n = 47) were excluded. We compared international normalized ratio values and the time interval from arrival to the report of test results (door-to-international normalized ratio time) between point-of-care testing for the prothrombin time international normalized ratio and central laboratory testing for the prothrombin time international normalized ratio. In patients who underwent thrombolysis, we compared the time interval from arrival to thrombolysis (door-to-needle time) between the current study population and historic cohort at our center.

Results:

In the 155 patients included in the study, the median door-to-international normalized ratio time was 9.0 min (interquartile range, 5.0–12.0 min) for point-of-care testing for the prothrombin time international normalized ratio and 46.0 min (interquartile range, 38.0–55.0 min) for central laboratory testing for the prothrombin time international normalized ratio (p < 0.001). The intraclass correlation coefficient between point-of-care testing for the prothrombin time international normalized ratio and central laboratory testing for the prothrombin time international normalized ratio was 0.975 (95% confidence interval: 0.966–0.982). Forty-nine of the 155 patients underwent intravenous thrombolysis. The door-to-needle time was significantly decreased after implementation of point-of-care testing for the prothrombin time international normalized ratio (median, 23.0 min; interquartile range, 16.0–29.8 vs median, 46.0 min; interquartile range, 33.5–50.5 min).

Conclusion:

Utilization of point-of-care testing for the prothrombin time international normalized ratio was feasible in the management of patients with acute ischemic stroke. Point-of-care testing for the prothrombin time international normalized ratio was quick and reliable and had a pivotal role in expediting thrombolysis.

Point-of-care versus central laboratory testing of INR in acute stroke

OBJECTIVES

Effective anticoagulant therapy is a contraindication to thrombolysis, which is an effective treatment of ischemic stroke if given within 4.5 hours of symptom onset. INR above 1.7 is generally considered a contraindication for thrombolysis. Rapid measurement of INR in warfarin-treated patients is therefore of major importance in order to be able to decide on thrombolysis or not. We asked whether INR measured on a point-of-care instrument would be as good as a central laboratory instrument.

MATERIAL AND METHODS

A total of 529 consecutive patients who arrived at the emergency department at a large urban teaching hospital with stroke symptoms were enrolled in the study. INR was measured with a CoaguChek and a Sysmex instrument. Basic clinical information such as age, sex, and diagnosis (if available) was recorded. INR from the instruments was compared using linear regression and Bland-Altman plot.

RESULTS

Of 529 patients, 459 had INR results from both instruments. Among these, 3 patients were excluded as outliers. The rest (n = 456) showed good correlation between the methods (R²  = 0.97). In the current setting, CoaguChek was in median 63 minutes faster than Sysmex.

CONCLUSION

Our results indicate that point-of-care testing is a safe mean to rapidly acquire a patient's INR value in acute clinical situations.

Thrombolysis in stroke patients: Comparability of point-of-care versus central laboratory international normalized ratio

BACKGROUND

In acute stroke patients, thrombolysis is one gold standard therapy option within the first four hours after the ischemic event. A contraindication for thrombolysis is an International Normalized Ratio (INR) value >1.7. Since time is brain, rapid and reliable INR results are fundamental. Aim was to compare INR values determined by central laboratory (CL) analyzer and Point-of-Care Testing(POCT)-device and to evaluate the quality of POCT performance in cases of potential therapeutic thrombolysis at a certified stroke unit.

METHODS

In 153 patients INR measurements using POCT-devices (HEMOCHRON Signature Elite®) were compared to INR measurements (BCS®XP) performed at the central laboratory. Outlier evaluation was performed regarding the critical thrombolysis cut-off.

RESULTS

Overall, we demonstrated a significant correlation (r = 0.809, p<0.0001) between both measurement methods. Mean value of the absolute difference between CL-INR and POCT-INR measurements was 0.23. In 95.4% of these cases, no differences regarding the critical cut-off (INR 1.7) were observed. POCT-INR values tended to be higher than the CL-INR values (p = 0.01). In 4.6% cases, a different value regarding thrombolysis cut-off was found. All patients were >75 years.

CONCLUSIONS

POCT-INR measurements based on our POCT concept are suitable to determine INR values in critical stroke patients. Nevertheless, outlier evaluation is mandatory.

Point-of-Care-Testing in Acute Stroke Management: An Unmet Need Ripe for Technological Harvest

Stroke, the second highest leading cause of death, is caused by an abrupt interruption of blood to the brain. Supply of blood needs to be promptly restored to salvage brain tissues from irreversible neuronal death. Existing assessment of stroke patients is based largely on detailed clinical evaluation that is complemented by neuroimaging methods. However, emerging data point to the potential use of blood-derived biomarkers in aiding clinical decision-making especially in the diagnosis of ischemic stroke, triaging patients for acute reperfusion therapies, and in informing stroke mechanisms and prognosis. The demand for newer techniques to deliver individualized information on-site for incorporation into a time-sensitive work-flow has become greater. In this review, we examine the roles of a portable and easy to use point-of-care-test (POCT) in shortening the time-to-treatment, classifying stroke subtypes and improving patient's outcome. We first examine the conventional stroke management workflow, then highlight situations where a bedside biomarker assessment might aid clinical decision-making. A novel stroke POCT approach is presented, which combines the use of quantitative and multiplex POCT platforms for the detection of specific stroke biomarkers, as well as data-mining tools to drive analytical processes. Further work is needed in the development of POCTs to fulfill an unmet need in acute stroke management.

Point of care and factor concentrate-based coagulation algorithms

In the last years it has become evident that the use of blood products should be reduced whenever possible. There is increasing evidence regarding serious adverse events, including higher mortality and morbidity, related to transfusions. The use of point of care (POC) devices integrated in algorithms is one of the important mechanisms to limit blood product exposure. Any type of algorithm, especially the POC-based ones, allows goal-directed transfusions of blood products and even better targeted factor concentrate substitutions. Different types of algorithms in different surgical settings (cardiac surgery, trauma, liver surgery etc.) have been established with growing interest in their use as they offer objective therapy for management and reduction of blood product use. The use of POC devices with evidence-based algorithms is important in the bleeding patient independent of its origin (traumatic vs. surgical). The use of factor concentrates compared to the classical blood products can be cost-saving, beneficial for the patient, and in agreement with the WHO-requested standard of care. The empiric and uncontrolled use of blood products such as fresh frozen plasma, red blood cells, and platelets without POC monitoring should no longer be followed with regard to actual evidence in literature. Furthermore, the use of factor concentrates may provide better outcomes and potential for cost saving.