Anti-Xa assays: What is their role today in antithrombotic therapy?

Although some suggest anti-Xa assays should be the preferred method for monitoring intravenous unfractionated heparin therapy, which method is best is unknown owing to the lack of large randomized controlled trials correlating different assays with clinical outcomes. This article provides an overview of heparin monitoring and the pros, cons, and clinical applications of anti-Xa assays.