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Updated: Aug 9, 2025

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
New score for predicting major bleeding in patients with atrial fibrillation using direct oral anticoagulants
Jiana Chen1, Meina Lv1, Wenlin Xu1
1Department of Pharmacy, Fujian Maternity and Child Health Hospital College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, China.
Insights
A new Alfalfa-MB model predicts major bleeding in atrial fibrillation patients on direct oral anticoagulants (DOACs). This validated tool identifies key risk factors, aiming to improve patient safety and reduce bleeding events.
Area of Science:
- Cardiology
- Pharmacology
- Clinical Medicine
Background:
- Atrial fibrillation (AF) patients often require anticoagulation with direct oral anticoagulants (DOACs).
- Major bleeding is a significant complication in patients treated with DOACs.
- Predicting bleeding risk is crucial for optimizing anticoagulation therapy.
Purpose of the Study:
- To identify factors associated with major bleeding in AF patients on DOACs.
- To develop and externally validate a predictive model for major bleeding.
- To provide a validated clinical tool for assessing major bleeding risk.
Main Methods:
- Logistic regression was used to build the predictive model in a development cohort (4209 patients).
- External validation was performed using a separate cohort (1800 patients).
- Model performance was assessed using Area Under the Curve (AUC) and Hosmer-Lemeshow test.
Main Results:
- Age > 65, prior bleeding, anemia, vascular disease, antiplatelet/NSAID use, and rivaroxaban were independent risk factors for major bleeding.
- Gastrointestinal protective agents showed a protective effect.
- The Alfalfa-MB model achieved an AUC of 0.807 in development and 0.743 in external validation, outperforming existing scores.
Conclusions:
- The Alfalfa-MB model, based on 7 factors, accurately predicts major bleeding in AF patients on DOACs.
- The model demonstrated good discriminatory power and calibration in external validation.
- Alfalfa-MB may serve as an effective tool to mitigate major bleeding events in this patient population.
Purpose:
Our aim was to identify factors associated with major bleeding in patients with atrial fibrillation (AF) on direct oral anticoagulants (DOACs) and to construct and externally validate a predictive model that would provide a validated tool for clinical assessment of major bleeding.
Methods:
In the development cohort, prediction model was built by logistic regression, the area under the curve (AUC), and Nomogram. External validation, analytical identification and calibration of the model using AUC, calibration curves and Hosmer-Lemeshow test.
Results:
The development cohort consisted of 4209 patients from 7 centers and the external validation cohort consisted of 1800 patients from 12 centers. Multifactorial analysis showed that age > 65 years, history of bleeding, anemia, vascular disease, antiplatelet therapy/non-steroidal anti-inflammatory drugs and rivaroxaban were independent risk factors for major bleeding, and gastrointestinal protective agents was a protective factor. The Alfalfa-MB model was constructed using these seven factors (AUC = 0.807), and in the external validation cohort, the model showed good discriminatory power (AUC = 0.743) and good calibration (Hosmer-Lemeshow test P value of 0.205). The predictive power of the six bleeding scores was ORBIT (AUC = 0.706), HAS-BLED (AUC = 0.648), ATRIA (AUC = 0.645), HEMORR2 HAGES (AUC = 0.632), ABC (AUC = 0.619) and Shireman (AUC = 0.599) in descending order.
Conclusion:
Based on 7 factors, we derived and externally validated a predictive model for major bleeding with DOACs in patients with AF (Alfalfa-MB). The model has good predictive value and may be an effective tool to help reduce the occurrence of major bleeding in patients with DOACs.
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