ANTI-PLATELETS VITAMIN K ANTAGONIST NOVEL ANTICOAGULANTS LMWH COMBINATION ANTI-THROMBOTIC THERAPY LOW RISK PROCEDURES •  No change •  No change •  No change •  No change •  No change MEDIUM RISK PROCEDURES •  No change •  Local hemostatic measures •  For INR ≤ 4 No change •  Local hemostatic measures •  No change •  Local hemostatic measures •  No change •  Local hemostatic measures •  Consider withdrawal of one of the drugs prior to procedure* •  Restart after hemostasis is achieved HIGH RISK PROCEDURES •  No change •  Local hemostatic measures •  For INR ≤ 3 no change •  For INR > 3 consider •  Low risk for thromboembolism:  Withdraw drug or reduce dose to allow INR To fall •  High risk for thromboembolism: withhold warfarin, convert to LMWH.  Withhold LMWH on the morning of the procedure •  Withhold 24 hours prior to procedure •  Local hemostatic measures •  Restart after hemostasis is achieved •  Withhold 6 hours prior to procedure •  Local Hemostatic measures •  Restart after hemostasis is achieved •  Withhold one of the drugs prior to procedure* •  Restart after hemostasis is achieved * The decision of the number of days for drug withdrawal prior to procedure depends on the medication involved. For example, the typical recommendation for aspirin is discontinuation 3-5 days prior to planned procedure.

Table 3: Risk of procedures with regards to type of anti-thrombotic agents.