Table VII.

Duration of use of long-term anticoagulation (adapted from [49])

Variable	Recommended duration of treatment	Level of recommendation
An episode of VTE secondary to a transient risk factor	Continue anticoagulation with warfarin for 3 months	Grade 1A
An episode of VTE associated with concurrent cancer	Continue anticoagulation with LWMH for 3-6 months	Grade 1A
	Continue subsequent anticoagulation with warfarin or LMWH indefinitely or until cancer is resolved	Grade 1C
First episode of unprovoked	Continue anticoagulation with VKA for 3 months	Grade 1A
VTE	After first 3 months, continue anticoagulation with warfarin if risk-benefit ratio is favorable:	Grade 1A
	• Low risk for bleeding
	• Reliable follow-up for INR monitoring
Second episode of unprovoked VTE	Indefinite	Grade 1C