What is the best choice for prophylaxis against VTE in medical inpatients?

Duration of therapy: Most clinical trials have used prophylaxis for seven to 14 days. The Extended Clinical Prophylaxis in Acutely Ill Medical Patients (EXCLAIM) trial evaluated duration of therapy, the results of which were presented recently at the 21st Congress of the International Society on Thrombosis and Haemostasis (ISTH).

Of the 5,105 patients who met inclusion criteria, 5,049, or 99%, received open-label prophylaxis with enoxaparin (10 ± four days); 2,013 patients subsequently received extended-duration enoxaparin; and 2,027 received placebo (each for 28 ± four days). Subjects were at least 40 years old, had been recently immobilized (for at least 3 days) and had a predefined acute medical illness. Mobility was defined as level 1 (total bed rest or sedentary) or level 2 (bathroom privileges). After a planned blinded interim analysis, the trial’s data safety monitoring board recommended an amendment to the inclusion criteria, changing level 2 mobility to include age >75 years, and/or prior VTE, and/or diagnosed cancer.

When compared with placebo, extended-duration enoxaparin following the open-label, standard-duration enoxaparin reduced the relative risk of VTE by 44% (2.8% vs. 4.9%; p=0.0011). There was major bleeding in 12 subjects who received extended-duration enoxaparin and three subjects receiving placebo (0.6% vs. 0.1%; p=0.0192).

There was no difference in all-cause mortality between the extended-duration enoxaparin and placebo groups at six months (10.1% vs. 8.9%, p=0.179). The authors concluded 38 days of enoxaparin 40 mg SC once daily significantly reduced the overall incidence of VTE compared with a 10-day regimen in acutely ill medical patients with reduced mobility. This reduction in overall risk for VTE was consistent with a reduction in risk for asymptomatic proximal DVT and symptomatic VTE.

Based on this trial, we would recommend five weeks of prophylaxis for those older than 75 years with prior history of VTE or with active cancer. In the absence of these criteria, we recommend up to 14 days of therapy.

For many patients, this will mean prophylaxis after discharge from the hospital. While this represents a change in practice for many and may significantly complicate some discharge care plans we believe the significant burden of post-hospital VTE mandates a more aggressive approach to peri-hospitalization prophylaxis. 

Back to the Case

Our patient has acute decompensated heart failure and likely will be limited in his ability to ambulate. All the clinical trials discussed above included similar patients and support the use of pharmacological prophylaxis. All hospitalized medical patients should undergo VTE risk assessment and implementation of pharmacologic prophylaxis in the absence of contraindications. TH

Dr. Lenchus is an assistant professor of medicine at the University of Miami School of Medicine. Dr. Jaffer is an associate professor of medicine at the University of Miami School of Medicine, where he serves as the chief of the division of hospital medicine.

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