Evaluation of a heparin assay method using a fluorogenic synthetic peptide substrate for thrombin.

A heparin assay method based on thrombin cleavage of a fluorogenic synthetic peptide has been evaluated in normal subjects, in patients with chronic renal disease on hemodialysis, and in patients with other disorders. The method has satisfactory accuracy, sensitivity, and reproducibility. In contrast to methods commonly used to monitor heparin therapy, it measures heparin directly and is uninfluenced by patient variables such as low antithrombin III. The method may provide valuable information in selected clinical settings such as cardiopulmonary bypass and in patients with chronic renal disease who receive heparin during hemodialysis or prior to surgery.