of women in a family
ROME—According to researchers, a clinical decision rule can identify women who, after their first unprovoked venous thromboembolism (VTE), have a low risk of VTE recurrence and might safely discontinue anticoagulant therapy.
The researchers evaluated the HERDOO2 rule, which is named after the risk factors the rule employs to determine the likelihood of VTE recurrence, in the REVERSE II trial.
Results from the trial were presented at ESC Congress 2016 (abstract 5721).
According to the HERDOO2 rule, the following risk factors must be considered to determine a patient’s risk of VTE recurrence:
- Hyperpigmentation, Edema, or Redness in either leg
- D-dimer >250 μg/mL on anticoagulants
- Obesity with body mass index >30 kg/m2
- Older than age 65.
Women (but not men) are considered at low risk of VTE recurrence if they have 0 to 1 of these risk factors.
In the REVERSE II trial, researchers tested the HERDOO2 rule in 2779 male and female patients with a first unprovoked VTE who had completed 5 to 12 months of anticoagulant therapy.
After drop-outs and exclusions, 622 women were considered low-risk, based on HERDOO2 criteria, and the majority of these women (n=591) discontinued anticoagulant therapy.
Thirty-one low-risk women continued anticoagulant therapy, as did 1802 men and high-risk women (with 2 or more HERDOO2 criteria). Three hundred and twenty-three men and high-risk women discontinued anticoagulant therapy.
After a year of follow-up, low-risk women who had discontinued anticoagulants had a 3% rate of recurrent VTE per patient year, and low-risk women who continued anticoagulant therapy had no VTEs.
Among the men and high-risk women, the rate of recurrent VTE per patient year was 8.1% in patients who discontinued therapy and 1.6% in patients who continued to receive anticoagulant therapy.
“This is an important finding as, using our rule, over half of women with unprovoked VTE can safely discontinue anticoagulants and be spared the burdens, costs, and risks of life-long anticoagulation,” said study investigator Marc Rodger, MD, of Ottawa Hospital and University of Ottawa in Ontario, Canada.
“Since current consensus guidelines suggest anticoagulants should be continued indefinitely in all patients with unprovoked VTE and non-high bleeding risk, our results are potentially practice-changing.”
Dr Rodger noted, however, that questions remain regarding anticoagulation duration after a first unprovoked VTE.
“One is whether indefinite anticoagulation is required for men and high-risk women, [which] was not the primary focus of our study,” he said. “The second is in the subgroup of post-menopausal women aged 50 and above.”
“In this group, even those who were considered low-risk according to the HERDOO2 rule had a higher than expected rate of recurrent VTE (5.7%) when they discontinued anticoagulants. As such, further validation of HERDOO2 is required in this subset of post-menopausal women.”
