| High risk | Low risk |
| Prosthetic metal heart valve in mitral position | Prosthetic metal heart valve in aortic position |
| Prosthetic heart valve and atrial fibrillation | Xenograft heart valve |
| Atrial fibrillation and mitral stenosis | Atrial fibrillation without valvular disease |
| <3 months after venous thromboembolismThrombophilia syndromes | >3 months after venous thromboembolism |