Selecting Patients With Atrial Fibrillation for Anticoagulation

Abstract

Background— The rate of stroke in atrial fibrillation (AF) depends on the presence of comorbid conditions and the use of antithrombotic therapy. Although adjusted-dose warfarin is superior to aspirin for reducing stroke in AF, the absolute risk reduction of warfarin depends on the stroke rate with aspirin. This prospective cohort study tested the predictive accuracy of 5 stroke risk stratification schemes. Methods and Results— The study pooled individual data from 2580 participants with nonvalvular AF who were prescribed aspirin in a multicenter trial (Atrial Fibrillation, Aspirin, Anticoagulation I study [AFASAK-1], AFASAK-2, European Atrial Fibrillation Trial, Primary Prevention of Arterial Thromboembolism in patients with nonrheumatic Atrial Fibrillation in primary care study, and Stroke Prevention and Atrial Fibrillation [SPAF]-III high risk or SPAF-III low risk). There were 207 ischemic strokes during 4887 patient-years of aspirin therapy. All schemes predicted stroke better than chance, but the number of patients categorized as low and high risk varied substantially. AF patients with prior cerebral ischemia were classified as high risk by all 5 schemes and had 10.8 strokes per 100 patient-years. The CHADS 2 scheme (an acronym for Congestive heart failure, Hypertension, Age >75, Diabetes mellitus, and prior Stroke or transient ischemic attack) successfully identified primary prevention patients who were at high risk of stroke (5.3 strokes per 100 patient-years). In contrast, patients identified as high risk by other schemes had 3.0 to 4.2 strokes per 100 patient-years. Low-risk patients identified by all schemes had 0.5 to 1.4 strokes per 100 patient-years of therapy. Conclusions— Patients with AF who have high and low rates of stroke when given aspirin can be reliably identified, allowing selection of antithrombotic prophylaxis to be individualized.

Associations between illness beliefs, medication beliefs, anticoagulation‐related quality of life, and INR control: Insights from the Switching Study

“…Clinical and demographic data was collected and CHA 2 DS 2 VASc, CHADS 2 , HAS‐BLED, Charlson comorbidity index (CCI), and SAMe‐TT₂R scores calculated 26, 27, 28, 29, 30. As the HAS‐BLED scoring system for determining bleeding risk allocates 1 point for TTR <60% which is also the grouping variable, true HAS‐BLED and adjusted HAS‐BLED scores were calculated, where the adjusted HAS‐BLED score discounts the point allocated for TTR <60%.…”

Risk of bleeding in very old atrial fibrillation patients on warfarin: Relationship with ageing and CHADS2 score

“…Several international and national scientific societies [3,4] have produced guidelines to help physicians to stratify the risk of stroke according to the presence of different risk factors. In particular, a score has been recently proposed and validated to obtain an easy and practical stratification (CHADS 2 ) [5]. Age is one of the main risk factors for the occurrence of stroke and has consistently been considered a critical point in the different studies.…”

Novel Oral Anticoagulants Versus Warfarin Therapy at Various Levels of Anticoagulation Control in Atrial Fibrillation—A Cost-Effectiveness Analysis

“…26 The rate of ischemic stroke and percentage of ischemic strokes with major, minor or no deficit on aspirin were derived from prospective trials. 4,[27][28][29] The rate of major bleeding on aspirin was estimated from relative risk of bleeding on aspirin versus warfarin and the bleeding rate. 30,31 The mortality rates of intracranial hemorrhage, extracranial hemorrhage, ischemic stroke and acute myocardial infarction within 30 days of an event were estimated from observational studies.…”