Department of Cardiology, Inserm U942, Lariboisiere Hospital, AP-HP, Paris Diderot University, Sorbonne Paris Cité, Paris, France; Thrombosis and Atherosclerosis Research Unit, Vessels and Blood Institute (IVS), Anticoagulation Clinic (CREATIF), Lariboisiere Hospital, Paris VII University, EA 7334 REMES, Paris, France.
Department of Cardiology, Inserm U942, Lariboisiere Hospital, AP-HP, Paris Diderot University, Sorbonne Paris Cité, Paris, France.
Thromb Res. 2016 Apr;140:66-72. doi: 10.1016/j.thromres.2016.02.006. Epub 2016 Feb 20.
Vitamin K antagonists (VKA) are widely prescribed throughout the world. Patients on VKA therapy require international normalized ratio (INR) monitoring of venous blood to ensure the response remains within the therapeutic window. Point-of-care devices (POC-INR) can safely and easily monitor VKA efficacy but need to be evaluated in practice. The aim of this study was to assess the precision and accuracy of a new POC-INR (Qlab) compared to the laboratory plasma technique and the CoaguChek-XS system.
Consecutive patients on VKA referred to our institution were included. The study was designed to analyze 75 patients divided equally in the following subgroups: INR<2; INR=2-3; INR>3. INR was measured with an established laboratory method (INRREF) with an international sensitivity index of 1.0 and by two different POC-INRs: the Qlab (INRQlab) and the CoaguChek-XS systems (INRXS).
82 patients treated mainly for atrial fibrillation or venous thromboembolism disease were included. Precision in therapeutic range (INR=2-3) of both POC-INRs was satisfactory with a coefficient of variation of 4.6% for the Qlab and 4.3% for the CoaguChek-XS. INRRef was 2.70 ± 1.36, INRQlab 2.59 ± 1.25 and INRXS 2.89 ± 1.37. Accuracy was low with the Qlab (R(2)=0.64) and higher with the CoaguChek-XS (R(2)=0.94). The mean relative difference from the INRRef was higher for the Qlab (18.4%) than for the CoaguChek-XS (12.9%). Clinical concordance was lower with the Qlab (78.2%) than with the CoaguChek-XS (90.0%).
This study suggests that the Qlab has accuracy limitations with clinical consequences. New POC-INR devices require careful evaluation prior to clinical implementation.
维生素 K 拮抗剂（VKA）在全球范围内广泛应用。接受 VKA 治疗的患者需要对静脉血进行国际标准化比值（INR）监测，以确保治疗效果处于治疗窗口内。即时检测设备（POC-INR）可以安全、便捷地监测 VKA 疗效，但需要在实践中进行评估。本研究旨在评估新型即时检测 INR（Qlab）与实验室血浆检测技术和 CoaguChek-XS 系统的精确性和准确性。
连续纳入我院就诊的 VKA 治疗患者。本研究设计分析了 75 例患者，分为以下三个亚组，每组各 25 例：INR<2；INR=2-3；INR>3。INR 采用国际敏感度指数为 1.0 的建立实验室方法（INRREF）以及两种不同的即时检测 INR 设备：Qlab（INRQlab）和 CoaguChek-XS 系统（INRXS）进行检测。
共纳入 82 例主要因心房颤动或静脉血栓栓塞疾病而接受治疗的患者。两种即时检测 INR 设备在治疗范围内（INR=2-3）的精密度均令人满意，Qlab 的变异系数为 4.6%，CoaguChek-XS 的变异系数为 4.3%。INRRef 为 2.70±1.36，INRQlab 为 2.59±1.25，INRXS 为 2.89±1.37。Qlab 的准确性较低（R²=0.64），CoaguChek-XS 的准确性较高（R²=0.94）。与 INRRef 的平均相对差异，Qlab （18.4%）高于 CoaguChek-XS（12.9%）。与 CoaguChek-XS（90.0%）相比，Qlab 的临床一致性较低（78.2%）。
本研究表明 Qlab 存在准确性限制，具有临床影响。新型即时检测 INR 设备在临床应用前需要仔细评估。
