Stroke and bleeding risk stratification in atrial fibrillation: a critical appraisal

Abstract

Atrial fibrillation (AF) significantly increases the risk of stroke and, therefore, stroke prevention is an essential component of the management for patients with AF. This requires formal assessment of the individual risk of stroke to determine if the patient is eligible for oral anticoagulation (OAC), and if so, their risk of bleeding on OAC, before a treatment decision regarding stroke prevention is made. Risk of stroke is not homogenous; it depends on the presence or absence of risk factors. A plethora of stroke and bleeding risk factors has been identified, including common and less-well established clinical risk factors, plus imaging, urine, and blood biomarkers. Consequently, there are several stroke and bleeding risk stratification scores available and this article provides an overview of them, the risk factors included and how they are scored, and provides a critical appraisal of them. The review also discusses the debate regarding whether female sex is a risk factor or a risk modifier, and highlights the dynamic nature of both stroke and bleeding risk and the need to re-assess these risks periodically to ensure treatment is optimal to reduce the risk of adverse outcomes. This review also summarizes the recommended stroke and bleeding risk stratification scores from all current major international guidelines.

Keywords: Atrial fibrillation; Bleeding; CHA2DS2-VASc; HAS-BLED; Risk scores; Risk stratification; Stroke.

Figure 1

Atrial fibrillation better care pathway. ABC, atrial fibrillation better care; APT, antiplatelet therapy; BP, blood pressure; CHA₂DS₂-VASc, congestive heart failure, hypertension, age ≥75 years (2 points), diabetes, stroke/TIA/thromboembolism (2 points), vascular disease, age 65–74 years, sex category (female); DM, diabetes mellitus; HAS-BLED, (uncontrolled) hypertension, abnormal renal, or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs/drink (alcohol); HF, heart failure; NOAC, non-vitamin K antagonist oral anticoagulant; NSAIDs, non-steroidal anti-inflammatory drugs; OAC, oral anticoagulation; OSA, obstructive sleep apnoea; TTR, time in the therapeutic range; VKA, vitamin K antagonist. ↓, reduced/decreased. Adapted from Ref.