April 4, 2016 – Women with an additional risk factor for stroke might have a numerically higher number of cardiovascular and bleeding events.
A study of U.S. atrial fibrillation patients found a low absolute risk of stroke, transient ischemic attack, and death among patients who were evaluated as being low risk based on the CHA2DS2-VASc Score for Atrial Fibrillation Stroke Risk (a score of zero or one). The study also found that women with an additional risk factor for stroke might have a numerically higher number of cardiovascular and bleeding events.
The study’s lead author, DCRI’s Larry R. Jackson II, MD, (pictured) and colleagues conducted their analysis using the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF). The results were presented on Sunday at the annual Scientific Sessions of the American College of Cardiology in Chicago.
Atrial fibrillation imparts significant morbidity and confers a four- to five-fold increased risk of ischemic stroke. Evidence from several major European studies suggests that patients with a CHA2DS2-VASc score of 1 should receive oral anticoagulation, based on the incidence and risk of stroke and systemic embolism. However, under current medical society guidelines for patients with a CHA2DS2-VASc score of 1 in the United States, a variety of strategies may be considered, including no therapy, aspirin alone, or oral anticoagulation.
The CHA2DS2-VASc scoring method takes into account factors including a patient’s history of congestive heart failure, hypertension, stroke, transient ischemic attack, thromboembolism and vascular disease, and whether they have diabetes.
Jackson’s analysis included 10,137 patients enrolled between June 2010 and August 2011 from 176 clinical practices in the United States. It found a fairly high use of oral anticoagulation, of at least around 40 percent of patients with scores of 0 and 1 and women with an additional risk factor for stroke. Stroke rates were very low overall.
“The ambiguity in U.S. guidelines relating to oral anticoagulation in low-risk patients poses a challenge in clinical practice,” Jackson said. “Our data suggest that the overall event rate is low, but that women may need additional attention given their increased risk of major outcomes. Further studies are needed to clarify the optimal oral anticoagulation strategy in this population.”
In addition to Jackson, DCRI authors included Laine Thomas, PhD; Eric D. Peterson, MD, MPH; and Jonathan P. Piccini Sr., MD, MHS, for the ORBIT-AF Investigators.