Epidemiology:
- Prevalence: overall rates of thrombosis (with and without bridging therapy) are 0.9% among patients with atrial fibrillation (1).
Measurements:- Periprocedural risks of discontinuing antithrombotic therapy are extrapolated from risks outside the periprocedural period (1). For patients with nonvalvular atrial fibrillation, important determinants of the risk of stroke include the CHADS2 score (2) and, more recently, the CHA2DS2-VASc score, which includes cardiovascular atherosclerotic disease and female sex as additional risk factors (3). Valvular atrial fibrillation implies the coexistence of severe valvular heart disease (mechanical valvular prosthesis or mitral-valve repair), and affected patients are at high risk for thromboembolism (1).
- CHADS2-Score (2,4):Â
| Score | Risk | Anticoagulation Therapy | Considerations |
|---|
| 0 | Low | None or Aspirin | Aspirin daily | | 1 | Moderate | Aspirin or Warfarin | Aspirin daily or raise INR to 2.0-3.0 | | >=2 | High | Warfarin | Raise INR to 2.0-3.0, unless contraindicated |
- CHA2DS2-VASc-Score (3):
| Risk Factor | Score | | Congestive heart failure/left-ventricular dysfunction | 1 | | Hypertension | 1 | | Age ≥ 75 y | 2 | | Diabetes mellitus | 1 | | Stroke/TIA/Thromboembolism | 2 | | Vascular disease (prior myocardial infarction, peripheral artery disease, or aortic plaque) | 1 | | Age 65-74 y | 1 | | Sex category (ie female gender) | 1 |
Treatment: - According to CHADS2-Score (4):Â
| Score | Risk | Anticoagulation Therapy | Considerations |
|---|
| 0 | Low | None or Aspirin | Aspirin daily | | 1 | Moderate | Aspirin or Warfarin | Aspirin daily or raise INR to 2.0-3.0, depending on patient preference | | 2 or greater | Moderate or High | Warfarin | Raise INR to 2.0-3.0, unless contraindicated
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- According to CHA2DS-Vasc (3):
  References: - Current Concepts: Management of Antithrombotic Therapy in Patients Undergoing Invasive Procedurs. NEJM. 2013;368(22):2113-2124: full text | pdf.
- Validation of Clinical Classification Schemes for Predicting Stroke: Results From the National Registry of Atrial Fibrillation. JAMA. 2001;285(22):2864-2870: full text | pdf.
- Refining Clinical Risk Stratification for Predicting Stroke and Thromboembolism in Atrial Fibrillation Using a Novel Risk Factor-Based Approach: The Euro Heart Survey on Atrial Fibrillation. Chest. 2010;137(2):263-272: full text | pdf.
- http://en.wikipedia.org/wiki/CHADS2_score [ accessed May 31st, 2013 ]
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