Pregnant women with mechanical valves are at particularly high risk for maternal death, thrombotic events, hemorrhagic events, miscarriages or fetal mortality, compared to pregnant women with tissue valves or other cardiac-related issues, according to results of the ROPAC trial presented Sept. 2 during ESC Congress 2014. Study investigators also noted a wide range of regimes for anticoagulation in pregnant women.

The study, which used data from the Registry of Pregnancy and Cardiac Disease, looked at 2,966 women with structural cardiac disease, aortic pathology or pulmonary hypertensions from 132 centers in 48 countries. Of these women, 212 had mechanical heart valves, 134 had tissue valves and 2,620 had no prosthetic valves.

According to the study, only 58 percent of women with mechanical valves had event-free pregnancies resulting in live births, compared to 78 percent of other cardiac patients. The percentage of women who suffered maternal mortality (1.4 percent), thrombotic events (6.1 percent), hemorrhagic events (23 percent), miscarriages after 24 weeks (15.6 percent) and fetal mortality less than 24 weeks (2.8 percent) were much higher than those with no prosthesis or tissue valves (0.2 percent, 0.4 percent, 5 percent, 1.7 percent and 0.6 percent, respectively).

Anticoagulation regimes made up of vitamin K antagonists, low molecular weight heparin, unfractured heparin or combinations of the three, also varied significantly during pregnancy, with no one regime proving to be clearly optimal. Regimes relying on vitamin K antagonists were associated with high rates of miscarriage, while the use of heparin in women with mechanical valves was associated with valve thrombosis, particularly during the first trimester.

Moving forward, study investigators suggest that pre-pregnancy counseling explaining the different treatment options and their complication rates should be mandatory and conducted by experienced professionals. In addition, they recommend that care for patients with mechanical valves should be concentrated in a few specialized centers given the high-risks associated with this group. Finally, they urge the use of shared decision making to determine the best anticoagulation regime for individual patients. Study investigators also note that further discussion is needed about choice of valve type in young women; interregional differences in care; and the development of guidelines to help guide anticoagulation in pregnant women.

Keywords: Vitamin K, Heart Valve Prosthesis, Decision Making, Heparin, Low-Molecular-Weight, Warfarin, Counseling, Live Birth, Registries, Thrombosis, Hypertension, Pulmonary, Fetal Mortality, Maternal Mortality, Pregnancy Trimester, First, Pregnancy