Heparin prevents recurrent VTE in cancer patients

,; ,

Q&A

Heparin prevents recurrent VTE in cancer patients

J Fam Pract. 2003 November;52(11):828-848

By

Timothy L. Clenney, MD, MPH

Anthony J. Viera, MD

BACKGROUND: Patients with cancer who have had an episode of VTE have a substantial risk of both recurrent VTE and hemorrhagic complications from anticoagulation. Oral anticoagulant therapy in patients with cancer is more difficult due to the effect of drug interactions, malnutrition, liver dysfunction, chemotherapy, and poor venous access. Low-molecular-weight heparin may be an effective, practical alternative due to its predictable pharmacokinetics and drug interactions, making laboratory monitoring unnecessary.
POPULATION STUDIED: This multicenter study enrolled 676 of 864 eligible outpatients from 48 clinical centers in 8 countries. Eligible patients were adults with active cancer and newly diagnosed VTE (symptomatic proximal deep venous thrombosis or pulmonary embolism, or both). Patients had to be ambulatory and capable of all self-care. Patients were excluded if they had received heparin for more than 48 hours before randomization, were already receiving oral anticoagulant therapy, were at high risk for bleeding, or had a platelet count less than 75,000/cm³.
STUDY DESIGN AND VALIDITY: This was a single-blinded, randomized controlled trial using concealed allocation. All 676 patients were given the low-molecular-weight heparin dalteparin in a dose of 200 IU/kg for 5 to 7 days. The 338 patients in the dalteparin group were continued at the same dose (200 IU/kg) for the remainder of the first month, followed by 150 IU/kg for 5 months. The 338 patients in the oral anticoagulant group received warfarin, with a goal international normalized ratio (INR) of 2.5 (therapeutic range 2.0–3.0), for the remainder of the 6-month study period. For subjects that developed thrombocytopenia during the study, drug dosages were adjusted according to a protocol.
OUTCOMES MEASURED: The primary outcome measured was the first episode of recurrent VTE, either a documented symptomatic deep venous thrombosis, pulmonary embolism, or both. Secondary outcomes measured included clinically overt bleeding and death.
RESULTS: Both groups had similar baseline characteristics. Ninety percent of the patients had solid tumors and 67% had metastatic disease. In each group, approximately two thirds qualified for enrollment due to deep venous thrombosis alone, while approximately one third had a previous pulmonary embolism, with or without deep venous thrombosis.

PDF Download

Heparin prevents recurrent VTE in cancer patients

Recommended Reading