Literature at a Glance
A guide to this month’s studies
- Rivaroxaban for VTE
- Cost-effectiveness of dabigatran in atrial fibrillation
- Effect of new resident duty-hour limits
- Outcomes of care at acute-stroke centers
- Effect on MIC in patients with MRSA pneumonia
- Optimal hemodialysis frequency
- Effect of BNP testing on hospital length of stay
- Impact of herpes zoster vaccination
- 30-day readmission rates in for-profit hospitals
Oral Rivaroxaban Could Play a Role in VTE Treatment
Clinical question: Is oral rivaroxaban an acceptable treatment option for acute symptomatic deep-vein thrombosis (DVT) and venous thromboembolism (VTE)?
Background: Treatment of acute DVT requires frequent laboratory monitoring, which may be obviated by the use of fixed-dose oral rivaroxaban.
Study designs: Parallel randomized, open-label, event-driven, noninferiority study (the acute DVT study) and randomized, double-blind, placebo-controlled, event-driven superiority trial (continued treatment study).
Setting: Multicenter study.
Synopsis: The acute DVT study randomly assigned 3,449 patients with acute DVT to oral rivaroxaban 15 mg twice daily for three weeks followed by 20 mg daily for three, six, or 12 months or enoxaparin 1 mg/kg subcutaneously twice daily and daily warfarin until a therapeutic INR was achieved, at which time the enoxaparin was discontinued. Rivaroxaban was not inferior in terms of preventing recurrent VTE (2.1% vs. 3.0%; P<0.001). Major or clinically relevant nonmajor bleeding occurred equally in both groups (8.1%).
The continued treatment study randomly assigned 1,196 patients with six to 12 months of prior VTE treatment to rivaroxaban 20 mg daily versus placebo for six or 12 months. Rivaroxaban was superior in preventing recurrent VTE (1.3% vs. 7.1%; P<0.001). A statistically nonsignificant increase in major bleeding was reported with rivaroxaban (0.7% vs. 0.0%). The open-label design and pharmaceutical support create potential for bias.
Bottom line: Oral rivaroxaban might offer a simplified, effective, and safe alternative to enoxaparin and warfarin for short- and long-term VTE treatment.
Citation: The EINSTEIN Investigators. Oral rivaroxaban for symptomatic venous thromboembolism. N Engl J Med. 2010;363 (26):2499-2510.
Dabigatran Might Be a Cost-Effective Alternative to Warfarin in Atrial Fibrillation
Clinical question: Is dabigatran cost-effective compared to warfarin for prevention of stroke in atrial fibrillation?
Background: Dabigatran, a direct thrombin inhibitor, is FDA-approved for the prevention of stroke and systemic embolism in atrial fibrillation. In the 2009 RE-LY trial, dabigatran 150 mg twice daily was associated with fewer embolic strokes than warfarin with similar episodes of major hemorrhage. Dabigatran costs more than warfarin; its cost-effectiveness is unknown.
Study design: Markov decision model.
Setting: Data from the Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY), a multinational randomized trial, and other anticoagulation studies.
Synopsis: This model simulated costs and outcomes for a theoretical cohort of patients >65 with atrial fibrillation and CHADS2 score ≥1 taking either lifelong warfarin or dabigatran. The model included assumptions about costs and quality-of-life effects of INR monitoring, stroke, hemorrhage, and myocardial infarction. Because U.S. pricing for dabigatran was pending, the authors assumed $13 per day.