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

Background:The rate of major hemorrhage during the initial treatment with unfractionated heparin (UFH) in patients with deep venous thrombosis (DVT) and pulmonary embolism (PE) in routine clinical practice is understudied.In recent clinical trials an overall average of 3.8% was reported.However, the incidence of this complication in routine patient care might be higher owing to less strict patient selection and lack of standardization in the administration of heparin.We have determined major bleeding rates during heparin treatment for DVT or PE in routine practice and compared these rates with data from clinical trials.Methods: Data on the occurrence of major hemorrhage were retrieved according to strict criteria from the records of patients who had received continuous intravenous UFH therapy to treat objectively documented DVT or PE in 3 hospitals.Results: After exclusion of 29 patients because of lack of objective diagnosis of DVT or PE and 25 patients because of initial treatment with low-molecular-weight hep-