This study is limited by its post-hoc identification and classification of patients using ICD-9-CM codes, which could have resulted in some misclassification. Also, this study includes only two teaching hospitals in an urban setting; the prevalence of hyponatremia might differ in other settings. Causality cannot be determined based on these results.
Bottom line: Hospitalized patients with hyponatremia have increased in-hospital and long-term mortality.
Citation: Waikar SS, Mount DB, Curhan GC. Mortality after hospitalization with mild, moderate, and severe hyponatremia. Am J Med. 2009;122(9):857-865.
Clopidogrel Plus Aspirin in Patients with Atrial Fibrillation Reduces Risk of Major Vascular Events
Clinical question: Does the addition of clopidogrel to aspirin therapy reduce the risk of major vascular events in patients with atrial fibrillation for whom vitamin K antagonists (VKAs) are unsuitable?
Background: Although VKAs reduce the risk of stroke in atrial fibrillation, many patients are unable to use VKAs and are treated with aspirin instead. The potential benefits of adding clopidogrel to aspirin therapy in this population are unknown.
Study design: Randomized controlled trial.
Setting: Five hundred eighty medical centers in 33 countries.
Synopsis: More than 7,500 patients with atrial fibrillation who were also at high risk for stroke were randomly assigned to receive either clopidogrel or placebo once daily. All patients also received aspirin at a dose of 75 mg to 100 mg daily. A major vascular event occurred in 6.8% of patients per year who received clopidogrel and in 7.6% of patients per year who received placebo (RR 0.89, 95% CI, 0.89-0.98, P=0.01). This reduction primarily was due to a reduction in stroke, which occurred in 2.4% of patients per year who received clopidogrel, compared with 3.3% of patients per year who received placebo (RR 0.72, 95% CI, 0.62-0.83, P<0.001).
Major bleeding occurred in 2% of patients per year who received clopidogrel and in 1.3% of patients per year who received placebo (RR 1.57, 95% CI, 1.29-1.92, P<0.001).
Bottom line: Adding clopidogrel to aspirin in patients with atrial fibrillation who are not eligible for VKAs decreases the risk of major vascular events, including stroke, but increases risk of major hemorrhage compared with aspirin alone.
Citation: ACTIVE Investigators, Connolly SJ, Pogue J, et al. Effect of clopidogrel added to aspirin in patients with atrial fibrillation. N Engl J Med. 2009;360(20):2066-2078.