Anticoagulation for pregnant patients with mechanical heart valves

Abstract

Management of a pregnant patient with mechanical heart valve is a complex issue for all health care providers involved in the care of such patients. Complications may arise at any stage due to the increased haemodynamic load imposed by pregnancy or because of impaired cardiac performance often seen in these patients. In addition, the use of various cardiovascular drugs in pregnancy (especially anticoagulants) may lead tofoetal loss or teratogenic complications. Additionally, the risk of thrombo-embolic complications in the mother is increased by the hypercoagulable state of pregnancy. In this review, we have attempted to draw inferences to guide management of such patients based on the available literature. It seems that in pregnant women with mechanical heart valves, recent data support warfarin use throughout pregnancy, followed by a switch to heparin and planned induction of labour. However, the complexity of this situation demands a cafeteria approach where the patient herself can choose from the available options that are supported by evidence-based information. Unfortunately there is no consensus on such data. An overview of the available literature forms the basis of this review. In conclusion, a guideline comprising pragmatic considerations is preffered.

Warfarin-Associated Diaphragmatic Hernia: An Unusual Diagnosis

“…Notwithstanding, the optimal anticoagulant strategy remains to be established. One of the most commonly suggested regimens involves substituting warfarin with heparin between the 6th and 12th gestation weeks [ 12 ]. In spite of this early switch, it is well known that warfarin has a long half-life, and substitution at the 6th week may be too late to avoid embryopathy, as recently suggested by Walfisch and Koren [ 9 ].…”

Intracranial Hemorrhage in Pregnancy

“…It may also restrict the use of regional anesthesia at the time of delivery. UFH is a reliable drug when given intravenously and minimally crosses the placenta; however maintaining adequate anticoagulation with subcutaneous administration is difficult and is associated with higher maternal risk for thromboembolic complications 3. Last, LMWH has a better pharmacokinetic profile and may be considered an option for anticoagulation in pregnancy as suggested by the American Heart Association/American College of Cardiology guidelines 4,5…”

Follow-up and management of valvular heart disease patients with prosthetic valve: a clinical practice guideline for Indian scenario

“…Increase in fibrinogen factors VII, VIII, and X; von Willebrand factor; and a relative decrease in protein S activity, stasis, and venous hypertension during pregnancy results in the hypercoagulable state [ 151 ]. This hypercoagulable state extends into the postpartum period too and requires a persistently higher maintenance dose of VKAs [ 152 ].…”

“…Optimal anticoagulation therapy is essential for pregnant patients; however, the appropriate choice of agent among the existing options (VKA, UFH, or LMWH) is highly debatable [ 151 ]. The warfarin enables it to cross placental barriers and cause embryopathy.…”