Estudio comparativo de equipos INR capilar "point of care" versus INR venoso, en pacientes en tratamiento con antagonistas de vitamina K / Comparison of point of care capillary international normalized ratio (INR) with INR measured in venous samples

Background: INR is used to monitor the treatment with vitamin K antagonists. A strategy to reduce waiting times for sampling is to measure INR in a capillary sample using a portable point of care (POC) type coagulometer. Aim: To evaluate the correlation of CoaguChek Pro II™, Xprecia™ and microINR™ with venous INR measured at the clinical laboratory and their ease of use. Materials and Methods: Patients provided capillary and venous blood samples for parallel tests comparing Xprecia™ Stride with CoaguChek Pro II™ and with venous INR, microINR™ with CoaguChek Pro IITM and with venous INR. The devices' ease of use was assessed surveying the sampling staff. Results: The three tested devices had good correlation coefficients with venous INR: CoaguChek Pro IITM 0.953 and 0.962; Xprecia™ of 0.912 and microINR™ of 0.932. The correlation coefficient of Xprecia™ with CoaguChek Pro IITM was 0.937 and microINR™ with CoaguChek Pro IITM was 0.976. Conclusions: CoaguChek Pro IITM, Xprecia™ and microINR™ results had a good correlation coefficient with INR measured at the laboratory. Our results indicate that, in the hands of trained users, POC-type coagulometers are reliable and acceptable for routine use in anticoagulant treatment control.

Evaluation of CoaguChek(R) XS for Measuring Prothrombin Time in Patients Receiving Long-term Oral Anticoagulant Therapy / 대한진단검사의학회지

BACKGROUND: Oral anticoagulation with warfarin requires routine monitoring of prothrombin time to maintain the international normalized ratio (INR) within the appropriate therapeutic range. Coagu- Chek XS (Roche Diagnositic, Germany) is a portable coagulometer that measures the INR. We evaluated the precision and accuracy of CoaguCheck XS by comparing it with CA-1500 (Sysmex, Japan). METHODS: We analyzed the CV and the correlation of all INR results measured in 68 samples obtained from patients treated with warfarin and 10 samples from control subjects with no history of anticoagulant therapy with CoaguChek XS and CA-1500. We compared the turn-around time between two instruments and evaluated the differences between the results obtained with venous and capillary blood samples and those obtained with different lots of the test strip. We also evaluated the precision of the two instruments in 5 repeated tests with samples of normal and increased INR. RESULTS: Mean INR values of 5 repeated tests with the same samples were similar. The correlation of INR values between two instruments was excellent (r2=0.97, P=0.001), and the difference in the values between the two instruments was mostly within the 95% limit of agreement, but was shown to increase in direct proportion to INR values. The turn-around time of CoaguChek XS was shorter than that of CA-1500. The differences between venous and capillary blood and between different lots of the test trip were not significant (P>0.05). CONCLUSIONS: CoaguChek XS showed a good precision and correlation with CA-1500 with a very short turn-around time. This instrument should be clinically useful in monitoring INR of patients with oral anticoagulation.