Abstract 15580: Use of Anti-Coagulant/Anti-Platelet Therapy for Atrial Fibrillation in the US Outpatient Settings: is it Guided by Appropriate Risk Stratification?
Background New oral anticoagulant agents are becoming increasingly available now. However, there is limited information on the recent use of anticoagulation and anti-platelet therapy for atrial fibrillation (AF) in the outpatient settings in the US.
Methods Using the National Ambulatory Medical Care Survey (NAMCS) dataset, we estimated the prescription of anti-coagulant/anti-platelet agents among patient-visits when AF (ICD-9-CM code 427.31) was recorded as one of the three major diagnoses, stratifying by CHADS2 score.
Results Of the average 0.95 billion outpatient visits per year in the US, 8.3 million (age 73.7±0.5 years, women 52.3%, blacks 5.2%, whites 83.4%) had AF as a major reason for the visit. The prevalence of clinical conditions included in the CHADS2 score were as follows: CHF (17.2%), Hypertension (62.5%) , Age>75 years (50.4%), Diabetes (18.2%), Stroke/TIA (8.1%). The percentage of patients with CHADS2 score from 0 to 6 were 13.1%, 35.8%, 31.5%, 14.2%, 4.0%, 1.3%, and 0.1%, respectively. The overall use of anticoagulant agent alone was 37.9%, anti-platelet alone 10.7%, and both were 7.5%. The proportion of patients on anticoagulant agent with CHADS2 score from 0 to 6 were 44.0%, 43.7%, 50.1%, 39.7%, 53.6%, 31.9%, and 20.3% respectively. Similarly, the proportion on anti-platelet therapy by increasing CHADS2 score were 13.8%, 18.5%, 23.2%, 12.7%, 12.4%, 13.1%, and non-estimable, respectively.
Conclusions The use of anticoagulant in patients with AF who have low stroke risk - in whom anti-platelet therapy may suffice - is high, whereas their use in those with high risk is low. The reasons for these discrepancies need study especially with the availability of newer anticoagulant agents.
- © 2011 by American Heart Association, Inc.