Atrial fibrillation: Risk of embolization
- Warren J Manning, MD
Warren J Manning, MD
- Section Editor — Noninvasive Cardiac Imaging and Stress Testing
- Professor of Medicine and Radiology
- Harvard Medical School
- Daniel E Singer, MD
Daniel E Singer, MD
- Professor of Medicine
- Harvard Medical School
- Section Editors
- Peter J Zimetbaum, MD
Peter J Zimetbaum, MD
- Section Editor — Cardiac Arrhythmias
- Professor of Medicine
- Harvard Medical School
- Scott E Kasner, MD
Scott E Kasner, MD
- Section Editor — Stroke
- Professor of Neurology
- University of Pennsylvania School of Medicine
The most serious common complication of atrial fibrillation (AF) is arterial thromboembolism; the most clinically evident thromboembolic event is ischemic stroke. (See "Initial assessment and management of acute stroke" and "Pathophysiology of ischemic stroke".)
Peripheral embolization accounts for less than 10 percent of all such events and many of these are subclinical [1-3]. Knowledge of the risk of stroke (and peripheral embolization) is important for two reasons: to help the patient better understand AF and its potential complications; and, more importantly, to help determine which patients might benefit from interventions to prevent thromboembolism.
Antithrombotic therapy with oral anticoagulant has been shown to lower the risk of clinical thromboembolism in virtually all patients with AF, including all levels of risk and irrespective of type (paroxysmal, persistent, or permanent). (See "Overview of atrial fibrillation", section on 'General classification'.)
However, in the lowest-risk patients, the risk and impact of anticoagulant-related major bleeding may equal or exceed those of clinical thromboembolism without anticoagulant therapy. Thus, for these lowest-risk patients, clinicians need guidance regarding when to recommend such therapy. Risk prediction models have been developed for this purpose, although each has significant limitations. We prefer the CHA2DS2-VASc model and will focus on it in this topic. (See 'Options for estimating risk in the individual patient' below.)
The individual predictors and the models used to predict embolic risk in patients with nonvalvular AF are discussed in this topic. The way in which the risk models are used in clinical decision making regarding antithrombotic therapy is discussed separately. (See "Atrial fibrillation: Anticoagulant therapy to prevent embolization", section on 'Clinical use of anticoagulants'.)
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- PATIENTS WITH VALVULAR HEART DISEASE
- RISK FACTORS
- Clinical predictors
- Type of AF
- Duration and frequency in PAF
- Subclinical AF
- Rhythm versus rate control
- Imaging predictors
- FUNDAMENTAL CONCEPTS IN RISK ESTIMATION
- DEFINITION OF RISK CATEGORIES
- ONE-RISK-FACTOR PATIENTS
- OPTIONS FOR ESTIMATING RISK IN THE INDIVIDUAL PATIENT
- Individual stroke risk scores
- Comparison of models
- OUR APPROACH TO RISK ESTIMATION
- ATRIAL FLUTTER
- RECOMMENDATIONS OF OTHERS
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS