Trends in antithrombotic therapy for atrial fibrillation: Data from the Veterans Health Administration Health System.

BACKGROUND: Although controversial, several prior studies have suggested that oral anticoagulants (OACs) are underused in the US atrial fibrillation (AF) population. Appropriate use of OACs is essential because they significantly reduce the risk of stroke in those with AF. In the >2 million Americans with AF, OACs are recommended when the risk of stroke is moderate or high but not when the risk of stroke is low. To quantify trends and guideline adherence, we evaluated OAC use (either warfarin or dabigatran) in a 10-year period in patients with new AF in the Veterans Health Administration. METHODS: New AF was defined as at least 2 clinical encounters documenting AF within 120 days of each other and no previous AF diagnosis (N = 297,611). Congestive Heart Failure, Hypertension, Age > 75, Diabetes, and Stroke (CHADS2) scores were determined using age and diagnoses of hypertension, diabetes, heart failure, and stroke or transient ischemic attack during the 12 months before AF diagnosis. Receipt of an OAC within 90 days of a new diagnosis of AF was evaluated using VA pharmacy data. RESULTS: Overall, initiation of an OAC fell from 51.3% in 2002 to 43.1% in 2011. For patients with CHADS2 score of 0, 1, 2, 3, 4, and 5-6, the proportions of patients prescribed an OAC showed a relative decrease of 26%, 23%, 14%, 12%, 9%, and 13%, respectively (P < .001). Clopidogrel use was stable at 10% of the AF population. CONCLUSIONS: Among US veterans with new AF and additional risk factors for stroke, only about half receive OAC, and the proportion is declining.

Aspen increase soil moisture, nutrients, organic matter and respiration in Rocky Mountain forest communities.

Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were characterized as aspen dominated, mixed, conifer dominated or open meadow, which includes the range of vegetation conditions that exist in seral aspen forests. Soil chemistry, moisture content, respiration, and temperature were measured. There was a consistent trend in which aspen stands demonstrated higher mean soil nutrient concentrations than mixed and conifer dominated stands and meadows. Specifically, total N, NO(3) and NH(4) were nearly two-fold higher in soil underneath aspen dominated stands. Soil moisture was significantly higher in aspen stands and meadows in early summer but converged to similar levels as those found in mixed and conifer dominated stands in late summer. Soil respiration was significantly higher in aspen stands than conifer stands or meadows throughout the summer. These results suggest that changes in disturbance regimes or climate scenarios that favor conifer expansion or loss of aspen will decrease soil resource availability, which is likely to have important feedbacks on plant community development.