Predictors of Nontherapeutic Anticoagulation with Unfractionated Heparin

Two thirds of patients who received weight-based UFH had nontherapeutic anticoagulation; predictors included older age, female sex, lower weight, and impaired renal function.

Unfractionated heparin (UFH) is commonly used in patients with acute coronary syndromes because of its short half-life and reversibility. Unfortunately, however, response to UFH is unpredictable and requires close monitoring with laboratory tests. Previous studies have indicated that lack of adherence to weight-based dosing contributes to suboptimal anticoagulation.

Researchers evaluated factors associated with nontherapeutic UFH anticoagulation in a subgroup of patients who received UFH in an international randomized trial that compared fibrinolytic therapy plus either UFH or enoxaparin for treatment of ST-segment-elevation myocardial infarction. The study protocol mandated activated partial thromboplastin time (aPTT) testing at a central l…

Reviewing Author

Aaron E. Bair, MD, MSc, FAAEM, FACEP