Author + information
- Richard Godin, PhD∗ ( and )
- Marie-Claude Tanguay, MD
- ↵∗Department of Obstetrics and Gynecology, CHU Pierre-Boucher, Université de Montréal, 4951 rue Ontario, #202, Montreal, Quebec H1V1M3, Canada
After reading the elegant review by Steinberg et al. (1) on maternal and fetal outcomes of anticoagulation in pregnant women with mechanical heart valves (MHVs), we remain undecided on the best anticoagulation regimen for these patients. We would like to offer in response to this review a counterintuitive proposition that may serve as a compromise between the maternal risks associated with low-molecular-weight-heparins (LMWHs) and the fetal risks associated with vitamin K antagonists (VKAs): direct oral anticoagulants (DOACs).
Evidence for use of DOACs in patients with MHVs, a population in whom the mainstay of therapy is VKA, remains unfavorable. However, DOACs may very well be more effective than LMWHs in preventing thrombotic complications in this setting (2) as it is in others. In addition, the data currently available on fetal exposure to DOACs suggest they may not have the embryotoxic properties of VKAs (3). VKA (category D in pregnancy according to the US Food and Drug Administration) has been associated with negative fetal outcomes due to both the direct hemorrhagic risks it poses to the fetus and to elevated risks of abnormal cartilaginous, skeletal, and central nervous system development. Although all DOACs (US Food and Drug Administration category C [except apixaban, which is category B]) cross the placenta and expose the fetus to certain bleeding risks, some of these agents have been shown to have significantly better bleeding profiles than an LMWH or VKA regimen across diverse indications. This advantage possibly holds true in both the mother and the fetus.
Complications of anticoagulation therapy in this setting often occur in the peripartum period. Maternal risks include surgical or postpartum hemorrhage, whereas critical bleeding can occur in the fetus as a result of trauma during delivery. However, the short half-life of DOACs would allow the following: 1) rapidly interrupting treatment should delivery occur prematurely, benefiting both the mother as well as the fetus; and 2) shortening the prolonged antepartum interruption required with VKAs.
We agree that it is premature to either support or dismiss this approach in the absence of additional data on both the fetal safety, as well as the thromboprophylactic properties, of DOACs in patients with MHV, but Steinberg et al. (1) got us thinking this topic should be investigated.
Please note: Dr. Godin is an employee of Bristol-Myers Squibb; and a former employee of Allergan. Dr. Tanguay has received honorarium from Allergan, AbbVie, Bayer, Merck, and Pfizer.
- 2017 American College of Cardiology Foundation
- Steinberg Z.L.,
- Dominguez-Islas C.P.,
- Otto C.M.,
- Stout K.K.,
- Krieger E.V.
- Beyer-Westendorf J.,
- Michalski F.,
- Tittl L.,
- et al.