Mechanical aortic valve replacement in young women planning on pregnancy: maternal and fetal outcomes under low oral anticoagulation, a pilot observational study on a comprehensive pre-operative counseling protocol

J Am Coll Cardiol. 2012 Mar 20;59(12):1110-5. doi: 10.1016/j.jacc.2011.10.899.

Abstract

Objectives: This pilot prospective observational study aimed to evaluate the maternal and fetal outcomes of pregnancies under low-dose oral anticoagulation therapy after aortic mechanical replacement.

Background: Need for valve replacement is still an issue for young women with native valve disease who are planning on future pregnancy. Choice of replacement device is a challenging clinical task.

Methods: A comprehensive pre-operative counseling protocol to guide choice of replacement device was developed. The pre-operative anticoagulation trial to determine the warfarin daily dosage needed to reach target international normalized ratio (INR) represented the main stem of such protocol. Pregnancies on low-dose anticoagulation therapy (target INR: 1.5 to 2.5) were allowed in a highly selected subset of mechanical aortic valve recipients.

Results: Twenty-two patients of 40 originally referred for native valve disease surgery requiring valve replacement, safely underwent the pre-operative anticoagulation challenge. No maternal or fetal complications were detected in 16 pregnancies under low oral anticoagulation. Patterns of warfarin daily dosage and induced INRs were characterized during pregnancy.

Conclusions: In this small sample observational study, a pre-operative anticoagulation therapy trial helped young women scheduled for valve replacement to acquire complete information as to the choice of prosthetic device. In selected third-generation mechanical aortic prosthesis recipients, low-dose anticoagulation therapy seems safe and feasible for both mother and fetus. Further studies are needed to validate this approach.

MeSH terms

  • Administration, Oral
  • Adult
  • Algorithms
  • Anticoagulants / administration & dosage*
  • Aortic Valve / surgery*
  • Bioprosthesis / adverse effects
  • Confounding Factors, Epidemiologic
  • Counseling*
  • Drug Administration Schedule
  • Female
  • Gestational Age
  • Heart Valve Diseases / surgery*
  • Heart Valve Prosthesis Implantation* / adverse effects
  • Heparin, Low-Molecular-Weight / administration & dosage
  • Humans
  • International Normalized Ratio
  • Mitral Valve / surgery*
  • Pilot Projects
  • Pregnancy
  • Pregnancy Complications, Cardiovascular / surgery*
  • Pregnancy Outcome
  • Pregnancy Trimesters
  • Preoperative Period
  • Prospective Studies
  • Reoperation
  • Thrombosis / etiology
  • Thrombosis / prevention & control*
  • Treatment Outcome
  • Warfarin / administration & dosage

Substances

  • Anticoagulants
  • Heparin, Low-Molecular-Weight
  • Warfarin