Related Experiment Video
Updated: Feb 3, 2026

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
Published on: February 26, 2013
Predicting Thromboembolic and Bleeding Event Risk in Patients with Non-Valvular Atrial Fibrillation: A Systematic
Ethan D Borre1, Adam Goode1,2, Giselle Raitz1
1Department of Medicine, Duke University School of Medicine, Durham, North Carolina, United States.
Insights
For atrial fibrillation (AF) patients, CHADS₂, CHA₂DS₂-VASc, and ABC scores best predict stroke risk, while HAS-BLED best predicts bleeding risk. These tools aid in balancing stroke prevention against bleeding complications.
Area of Science:
- Cardiology
- Clinical Risk Assessment
- Medical Informatics
Background:
- Atrial fibrillation (AF) is a prevalent arrhythmia increasing stroke risk.
- Anticoagulant therapy for stroke prevention in AF carries a potential bleeding risk.
- Clinicians utilize risk stratification tools to balance stroke and bleeding risks for optimal patient management.
Purpose of the Study:
- To review and summarize existing literature on risk stratification tools for predicting stroke and bleeding in AF patients.
- To identify the most effective tools for assessing thromboembolic and bleeding risks in the context of AF management.
Main Methods:
- Systematic literature search of PubMed, Embase, and Cochrane Database of Systematic Reviews (2000-2018).
- Inclusion of English-language studies evaluating risk prediction tools for AF.
- Extraction of data on study design, patient characteristics, interventions, outcomes, quality, and applicability by two independent reviewers.
Main Results:
- Sixty-one studies assessed thromboembolic risk, and 38 assessed bleeding risk.
- CHADS₂, CHA₂DS₂-VASc, and ABC risk scores demonstrate the strongest evidence for predicting thromboembolic events (moderate strength).
- The HAS-BLED score shows the strongest evidence for predicting bleeding risk (moderate strength).
Conclusions:
- CHADS₂, CHA₂DS₂-VASc, and ABC scores are the most effective for predicting stroke events in AF.
- HAS-BLED is the most effective score for predicting bleeding risk in AF patients.
- Future research should explore the role of imaging and biomarkers in refining these risk prediction tools.
Background:
Atrial fibrillation (AF) is a common cardiac arrhythmia that increases the risk of stroke. Medical therapy for decreasing stroke risk involves anticoagulation, which may increase bleeding risk for certain patients. In determining the optimal therapy for stroke prevention for patients with AF, clinicians use tools with various clinical, imaging and patient characteristics to weigh stroke risk against therapy-associated bleeding risk.
Aim:
This article reviews published literature and summarizes available risk stratification tools for stroke and bleeding prediction in patients with AF.
Methods:
We searched for English-language studies in PubMed, Embase and the Cochrane Database of Systematic Reviews published between 1 January 2000 and 14 February 2018. Two reviewers screened citations for studies that examined tools for predicting thromboembolic and bleeding risks in patients with AF. Data regarding study design, patient characteristics, interventions, outcomes, quality, and applicability were extracted.
Results:
Sixty-one studies were relevant to predicting thromboembolic risk and 38 to predicting bleeding risk. Data suggest that CHADS2, CHA2DS2-VASc and the age, biomarkers, and clinical history (ABC) risk scores have the best evidence for predicting thromboembolic risk (moderate strength of evidence for limited prediction ability of each score) and that HAS-BLED has the best evidence for predicting bleeding risk (moderate strength of evidence).
Limitations:
Studies were heterogeneous in methodology and populations of interest, setting, interventions and outcomes analysed.
Conclusion:
CHADS2, CHA2DS2-VASc and ABC scores have the best prediction for stroke events, and HAS-BLED provides the best prediction for bleeding risk. Future studies should define the role of imaging tools and biomarkers in enhancing the accuracy of risk prediction tools.
Primary Funding Source:
Patient-Centered Outcomes Research Institute (PROSPERO #CRD42017069999).
Related Concept Videos
Amyloid Fibrils
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining,...
Amyloid Fibrils
Review and Preview
Percentiles are a type of fractile that partition data into...
Review and Preview
Bleeding in Fresh Concrete
Bleeding can cause several issues in the concrete structure. Sometimes, the rising water gets trapped beneath large aggregate...
Fibril-associated Collagen
For example, the type II collagen fibrils in cartilage have covalently bound type IX fibril-associated collagens at regular intervals. Other types of fibril-associated collagens are...

