Frequency of Major Hemorrhage in Patients Treated With Unfractionated Intravenous Heparin for Deep Venous Thrombosis or Pulmonary Embolism

Abstract

THE MOST important adverse effect of initial intravenous unfractionated heparin (UFH) therapy of deep venous thrombosis (DVT) and pulmonary embolism (PE) is major hemorrhage. In a large number of randomized clinical trials, the efficacy and safety of intravenous continuous UFH treatment has been compared with intravenous intermittent UFH treatment,^1-6 treatment with subcutaneously administered UFH,^7-14 and low-molecular-weight-heparin (LMWH).¹⁵ The overall average of major hemorrhage rates in the continuous intravenous UFH groups in these studies was 3.8% (95% confidence interval [CI] 3.0%-4.6%) (widely varying between the studies from 0% to 20%).