Synopsis: The study randomized 806 patients with renal-artery stenosis to receive either medical therapy alone (N=403) or medical management plus endovascular revascularization (N=403).
The majority of the patients who underwent revascularization (95%) received a stent.
The data show no significant difference between the two groups in the rate of progression of renal dysfunction, systolic blood pressure, rates of adverse renal and cardiovascular events, and overall survival. Of the 359 patients who underwent revascularization, 23 (6%) experienced serious complications from the procedure, including two deaths and three cases of amputated toes or limbs.
The primary limitation of this trial is the population studied. The trial only included subjects for whom revascularization offered uncertain clinical benefits, according to their doctor. Those subjects for whom revascularization offered certain clinical benefits, as noted by their primary-care physician (PCP), were excluded from the study. Examples include patients presenting with rapidly progressive renal dysfunction or pulmonary edema thought to be a result of renal-artery stenosis.
Bottom line: Revascularization provides no benefit to most patients with renal-artery stenosis, and is associated with some risk.
Citation: ASTRAL investigators, Wheatley K, Ives N, et al. Revascularization versus medical therapy for renal-artery stenosis. N Eng J Med. 2009;361(20):1953-1962.
Dabigatran as Effective as Warfarin in Treatment of Acute VTE
Clinical question: Is dabigatran a safe and effective alternative to warfarin for treatment of acute VTE?
Background: Parenteral anticoagulation followed by warfarin is the standard of care for acute VTE. Warfarin requires frequent monitoring and has numerous drug and food interactions. Dabigatran, which the FDA has yet to approve for use in the U.S., is an oral direct thrombin inhibitor that does not require laboratory monitoring. The role of dabigatran in acute VTE has not been evaluated.
Study design: Randomized, double-blind, noninferiority trial.
Setting: Two hundred twenty-two clinical centers in 29 countries.
Synopsis: This study randomized 2,564 patients with documented VTE (either DVT or pulmonary embolism [PE]) to receive dabigatran 150mg twice daily or warfarin after at least five days of a parenteral anticoagulant. Warfarin was dose-adjusted to an INR goal of 2.0-3.0. The primary outcome was incidence of recurrent VTE and related deaths at six months.
A total of 2.4% of patients assigned to dabigatran and 2.1% of patients assigned to warfarin had recurrent VTE (HR 1.10; 95% CI, 0.8-1.5), which met criteria for noninferiority. Major bleeding occurred in 1.6% of patients assigned to dabigatran and 1.9% assigned to warfarin (HR 0.82; 95% CI, 0.45-1.48). There was no difference between groups in overall adverse effects. Discontinuation due to adverse events was 9% with dabigatran compared with 6.8% with warfarin (P=0.05). Dyspepsia was more common with dabigatran (P<0.001).
Bottom line: Following parenteral anticoagulation, dabigatran is a safe and effective alternative to warfarin for the treatment of acute VTE and does not require therapeutic monitoring.
Citation: Schulman S, Kearon C, Kakkar AK, et al. Dabigatran versus warfarin in the treatment of acute venous thromboembolism. N Engl J Med. 2009;361(24):2342-2352.