Table 4.

Suggested approach to warfarin therapy interruption for invasive procedures

Days from Procedure	Anticoagulation management
7–14 days before	Assess recurrent VTE and procedure-related bleeding risk
	If high risk for VTE recurrence consider bridging with LMWH (unnecessary for most patients with VTE)
	Obtain baseline INR and determine number of warfarin doses to hold prior to procedure
7 days before	Stop aspirin or other antiplatelet therapy if deemed safe and necessary
4 or 5 days before	Stop warfarin
2 or 3 days before	Start LMWH if necessarya
Day before	Give last dose of LMWH 24 h before procedureb
	Verify INR is low enough to proceed with procedure Give vitamin K 2.5 mg orally if INR above goal for procedure
Day of	Resume usual maintenance warfarin dosec after procedure
1–3 days after	Resume LMWH if necessaryd
	Resume aspirin or other antiplatelet therapy once adequate hemostasis is verified
5 + days after	Stop LMWH once INR is therapeutic

^aLMWH usually initiated approximately 72 h prior to the procedure

^bGive only the morning dose of twice-daily therapeutic-dose LMWH and reduce once-daily therapeutic-doses by 50 %

^cUsing “booster” doses (e.g. 1.5–2 times the usual dose) for 1–2 days when resuming warfarin therapy may reduce time required to achieve INR ≥ 2.0 [108]

^dResume LMWH approximately 24 h after (e.g. the day after) the procedure for lower bleeding risk procedures; for high bleeding risk procedures wait 48 to 72 h and ensure adequate hemostasis before resuming LMWH, or avoid LMWH completely [68, 109]

INR international normalized ratio, LMWH low-molecular-weight heparin