Study design: Two double-blinded, randomized trials: an active-control study and a placebo-control study.
Setting: Two hundred sixty-five sites in 33 countries for the active-control study, and 147 sites in 21 countries for the placebo-control study.
Synopsis: This study enrolled 4,299 adult patients with objectively confirmed, symptomatic, proximal deep vein thrombosis or pulmonary embolism. In the active-control study comparing warfarin and dabigatran, recurrent objectively confirmed symptomatic or fatal VTE was observed in 1.8% of patients in the dabigatran group compared with 1.3% of patients in the warfarin group (P=0.01 for noninferiority). While major or clinically relevant bleeding was less frequent with dabigatran compared to warfarin (hazard ratio, 0.54), more acute coronary syndromes were observed with dabigatran (0.9% vs. 0.2%, P=0.02). In the placebo-control study, symptomatic or fatal VTE was observed in 0.4% of patients in the dabigatran group compared with 5.6% in the placebo group. Clinically relevant bleeding was more common with dabigatran (5.3% vs. 1.8%; hazard ratio 2.92).
Bottom line: Treatment with dabigatran met the pre-specified noninferiority margin in this study. However, it is worth noting that patients with VTE given extended treatment with dabigatran had significantly higher rates of recurrent symptomatic or fatal VTE than patients treated with warfarin.
Citation: Schulman S, Kearson C, Kakkar AK, et al. Extended use of dabigatran, warfarin, or placebo in venous thromboembolism. N Engl J Med. 2013;368(8):709-718.
Spironolactone Improves Diastolic Function
Clinical question: What is the efficacy of aldosterone receptor blockers on diastolic function and exercise capacity?
Background: Mineralocorticoid receptor activation by aldosterone contributes to the pathophysiology of heart failure (HF) in patients with and without reduced ejection fraction (EF). Aldosterone receptor blockers (spironolactone) reduce overall and cardiovascular mortality in HF patients with reduced EF; however, its effect on HF patients with preserved EF is unknown.
Study design: Prospective, randomized, double-blinded, placebo-controlled trial.
Setting: Ten ambulatory sites in Germany and Austria.
Synopsis: This study enrolled 422 men and women, aged 50 or older, with New York Heart Association (NYHA) Class II or III HF and preserved EF, and randomized them to receive spironolactone 25 mg daily or placebo for one year.
The endpoints included echocardiographic measures of diastolic function and remodeling; N-terminal pro b-type natriuretic peptide (NT pro-BNP) levels; exercise capacity; quality of life; and HF symptoms.
In the spironolactone group, there was significant improvement in echocardiographic measures of diastolic function and remodeling as well as NT pro-BNP levels. However, there was no difference in exercise capacity, quality of life, or HF symptoms when compared to placebo.
The spironolactone group had significantly lower blood pressure than the control group, which may account for some of the remodeling effects. The study may have been underpowered, and the study population might not have had severe enough disease to detect a difference in clinical measures. It remains unknown if structural changes on echocardiography will translate into clinical benefits.
Bottom line: Compared to placebo, spironolactone did improve diastolic function by echo but did not improve exercise capacity.
Citation: Edelmann F, Wachter R, Schmidt A, et al. Effect of spironolactone on diastolic function and exercise capacity in patients with heart failure with preserved ejection fraction: the Aldo-DHF randomized controlled trial. JAMA. 2013;309(8):781-791.
Real-Time, EMR-Based Prediction Tool Accurately Predicts ICU Transfer Risks
Clinical question: Can clinical deterioration be accurately predicted using real-time data from an electronic medical record (EMR), and can it lead to better outcomes using a floor-based intervention?