What is the target International Normalized Ratio (INR) range for someone with recurrent Deep Vein Thrombosis (DVT) due to Factor V Leiden?

Target INR for Recurrent DVT with Factor V Leiden

For a patient with recurrent DVT due to Factor V Leiden, the target INR should be 2.5 (range 2.0-3.0), the same standard therapeutic range used for all venous thromboembolism, and indefinite anticoagulation should be strongly considered given the recurrent nature of the thrombosis. 1

Standard Therapeutic Range Applies

• The presence of Factor V Leiden does not change the target INR range from the standard 2.0-3.0 (target 2.5) recommended for all DVT patients. 1, 2
• Higher INR ranges (such as 3.0-4.5) are not recommended for DVT and increase bleeding risk without additional benefit. 1
• The American College of Chest Physicians provides moderate-certainty evidence supporting this INR range over lower ranges (such as 1.5-1.9), as lower ranges significantly increase recurrent DVT risk with a relative risk of 3.25. 1

Critical Importance of Indefinite Anticoagulation in Recurrent DVT

• Recurrent DVT is a strong indication for indefinite anticoagulation regardless of thrombophilia status. 3
• The American Heart Association provides Class I, Level A evidence that patients with recurrent unprovoked DVT should be considered for indefinite therapy. 3
• Patients with unprovoked venous thromboembolism have an annual recurrence risk exceeding 5% after stopping anticoagulation, which substantially outweighs bleeding risk in well-managed warfarin therapy. 3

Factor V Leiden-Specific Considerations

• While Factor V Leiden heterozygotes have a modestly increased recurrence risk (odds ratio 1.36) compared to non-carriers, this does not warrant a higher INR target—it supports longer duration of therapy at standard intensity. 4
• The recurrence of DVT in your patient is the key factor driving the need for indefinite anticoagulation, not the Factor V Leiden mutation itself. 3
• No patient experienced recurrent events while maintained on warfarin with target INR 2.5 in Factor V Leiden cohorts, but median time to recurrence after stopping was only 9 years. 5

Practical Management Algorithm

• Maintain INR 2.0-3.0 (target 2.5) with warfarin therapy. 1, 2
• Ensure at least 45% time in therapeutic range to minimize both bleeding and recurrence risk. 2
• Schedule 6-month follow-up to evaluate for bleeding episodes or complications. 3
• Perform annual reassessment of risk-benefit ratio for all patients on extended anticoagulation. 3
• Monitor for development of high bleeding risk features (recurrent falls, need for dual antiplatelet therapy) that may require therapy reconsideration. 3

Common Pitfalls to Avoid

• Do not use historical lower INR targets (1.5-2.0 or 1.7-1.8) as these are not validated for safety or efficacy and increase recurrent thrombosis risk. 1
• Do not discontinue anticoagulation prematurely in recurrent DVT—this is a major error that leads to further thrombotic events. 6
• If INR falls below 2.0, immediately bridge with low molecular weight heparin (LMWH) until INR returns to therapeutic range for at least 24 hours. 6
• Do not assume Factor V Leiden requires a higher INR target—the standard range is appropriate and higher ranges only increase bleeding. 1, 2