Management of stroke prevention in canadian patients with atrial fibrillation at moderate to high risk of stroke.

Background: Many patients with atrial fibrillation who are at moderate to high risk of stroke do not receive anticoagulation with vitamin K antagonists (VKAs) in accordance with recommendations.

Objective: To determine (1) why Canadian patients with atrial fibrillation who are potentially eligible for VKA do not receive this therapy, (2) why Canadian primary care physicians discontinue VKA therapy, and (3) why VKA therapy is perceived as difficult to manage.

Methods: The study involved a chart review of 3 cohorts of patients with nonvalvular atrial fibrillation at moderate to high risk of stroke: patients who had never received VKA treatment (VKA-naive), those whose treatment had been discontinued, and those whose VKA treatment was considered difficult to manage.

Oligomerization of opioid receptors: generation of novel signaling units.

G-protein-coupled receptors such as opioid receptors exist in oligomeric complexes. Homo-oligomerization of mu, delta, and kappa opioid receptors has been demonstrated, suggesting a critical functional role for receptor-receptor interactions. Hetero-oligomerization creates delta-kappa and mu-delta receptor complexes, which display novel pharmacology, coupling to effector systems and signaling regulation properties.