HERDOO2 Rule for Discontinuing Anticoagulation in Unprovoked VTE

Why Use

Indefinite anticoagulation is burdensome and associated with bleeding risk. The HERDOO2 Rule can identify patients who have very low risk of recurrent VTE and can therefore safely stop anticoagulation in the short term.

When to Use

Women ≥18 years old with unprovoked VTE. Inclusion criteria in the original study: Patients diagnosed 5–7 months before enrollment. On heparin or low molecular weight heparin (LMWH) for ≥5 days and oral anticoagulation for 5–7 months after the event. Without recurrent VTE during the treatment period. Noncompressible segment on compression ultrasound of popliteal (or more proximal) leg vein, high-probability V/Q scan, or segmental (or larger) artery filling defect on spiral CT. Exclusion criteria: Leg fracture. Lower-extremity plaster cast. Immobilization for >3 days. General anesthetic <3 months before index event. Cancer diagnosis within 5 years.

Formula

Advice

The benefits and known risks of discontinuing anticoagulation in those deemed low-risk should be discussed with the patient.

More Information

Interpretation: HERDOO2 Risk group Risk of recurrent major VTE* Recommendation 0-1 Low 3.0% Can safely discontinue oral anticoagulation 2-4 Not low 7.4% Continue oral anticoagulation *Proximal DVT and segmental or greater PE, % per 100 patient years.