Anticoagulant management of pregnant women with mechanical heart valve replacement during perioperative period

To investigate the morbidity of complications and pregnancy outcomes in women with mechanical heart valve replacement who received low-dose oral anticoagulation treatment with warfarin throughout the pregnancy, compare the prognosis and complications of patients who were treated with single oral warfarin treatment or the “bridging” therapy treatment, investigate the influence of using vitamin K1 before emergency cesarean section delivery on postoperative warfarin anticoagulant effect and to explore an appropriate anticoagulant regimen during perioperative period for pregnant women with mechanical heart valve replacement.

46 pregnant women with mechanical heart valve replacement who received low-dose oral anticoagulation treatment from October 2008 to October 2014 treated at West China Women’s and Children’s Hospital were retrospectively reviewed. Eight patients received emergency cesarean section (CS), while 38 patients received selective CS, in which 17 patients received single oral warfarin and 21 patients received “bridging” anticoagulation treatment during postoperative period. Morbidity of complications and the time to achieve the target INR after operation were compared.

The mechanical valves were at the mitral position in 35 (76.09 %) patients, at the aortic position in 2 (4.35 %) patient and at both the mitral and aortic position in 9 (19.57 %) patients. 46 full-term healthy babies were delivered and no maternal thromboembolic was observed during pregnancy. There was no significant difference of the amount of uterine bleeding between single oral warfarin group and “bridging” treatment group during postpartum period. In single oral warfarin group, one valve thrombosis was observed and led to sudden death. No periphery thrombosis, hematoma, general hemorrhage or other sign of over-anticoagulation was observed. The INR increased more slowly in the group who received emergency CS with preoperative application of vitamin K1 than other two groups.

The use of vitamin K1 preoperatively might result in warfarin resistance and discontinuation of warfarin therapy before selective CS might be more appropriate than application of vitamin K1. The “bridging” anticoagulation treatment which combines oral warfarin and subcutaneous LMWH might be more effective and safer than single oral warfarin therapy for patients with mechanical heart valve replacement during postoperative period, no matter selective or emergency CS. The safety of low-dose oral warfarin therapy throughout pregnancy is still under controversy.