Health TrialsbyHealthPanel

Optimizing Anticoagulation in Pregnancies With Mechanical Heart Valves

ConditionsPregnancyProsthetic Heart ValveAnticoagulant Therapy
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexFemale
Age18-45
SponsorMount Sinai Hospital, Canada

About this trial

The purpose of this pilot study is to collect data on pregnancies with mechanical heart valves to see if using a blood thinner called low molecular weight heparin (LMWH) and low dose aspirin (LDA) is comparable to warfarin/vitamin K antagonist (VKA) to reduce the chance of clotting around the mechanical valve and improve survival. The study is a pilot study as the study investigators need to ensure that the blood levels needed for adequate amounts of LMWH and warfarin can be maintained during pregnancy to be able to compare LMWH and aspirin to warfarin. If this study shows that we can collect the tests that are needed for a larger study, the individuals' information who participated in this pilot study will be moved to the larger study. The larger study will compare survival, clot development and cardiac function as well as safety of these two common blood thinners.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Pregnant individuals with one or more MHVs

Who consent to participate

Are 18 years or older and

Less than 12 weeks gestation

Disqualifiers

Have a platelet count less than 50 x 10(9)/L as there is an increased risk of bleeding with thrombocytopenia, and/or

Have active bleeding defined as bleeding resulting in a hemoglobin reduction ≥10 g/L or in hemodynamic instability.

Have new valve thrombosis identified immediately prior to pregnancy

Trial design

Design model

Parallel

Treatments tested in this trial

  • LMWH and LDA

    Drug

    1\) Therapeutic LMWH throughout pregnancy either using weight-based dosing or dosing according to anti-Xa levels. The initial dose will be a twice daily therapeutic dose of 1.35U/kg (pregnancy weight) of enoxaparin or 135 U/kg (pregnancy weight) of dalteparin using prefilled syringes titrated to the higher dose prefilled syringe (i.e., not below the pregnancy weight-based dosing). 1. The dose of therapeutic LMWH can be adjusted by anti-Xa (done at least after four days of the start of LMWH or change in LMWH dose) levels or by pregnancy weight however, weight and anti-Xa levels will be determined for all participants using LMWH. Pregnancy weight in kilograms is to be determined every month. 2. If therapeutic LMWH is adjusted according to anti-Xa levels, peak and trough anti-Xa levels (done at least after four days of the start of LMWH or change in LMWH dose) are to be sent every four weeks or weekly if there is a change in dose.

  • Vitamin K antagonists (e.g warfarin)+/- LDA

    Other intervention

    VKAs during pregnancy: VKA use will require INRs every two weeks or weekly (done at least 5 days after starting or changing the dose) if there is a change in doses to ensure an INR of 2.5 for a patient with an aortic MVR (INR of 2 for the On-X AVR) and 3 for mitral MVR or two MHVs is met. LDA 81 mg to be added once pregnancy is confirmed.

  • Sequential therapy +/- LDA

    Other intervention

    LMWH at 6 weeks gestation until 12 weeks gestation prescribed according to the regimens above then VKAs from 12 weeks gestation until 34-36 weeks gestation followed by twice daily LMWH according to doses above until delivery. LDA to be added when pregnancy is confirmed

Treatment groups

100 Participants
are divided into 3 treatment groups
Group A: LMWH and LDAExperimental treatment 1 intervention
Group B: Vitamin K antagonists (e.g warfarin)+/- LDAOther 1 intervention
Group C: Sequential therapy +/-LDAOther 1 intervention

Trial outcomes

Primary outcomes

1

Primary outcome Measures

1\) Enrollment rate: To determine enrollment rate as defined by the number of patients enrolled/patients eligible, and consent rates (consent obtained/patients approached)

Time frame
At baseline
2

Adherence rate

To determine the adherence rate as defined as adherence to the anticoagulation regimen in 80% or more of the pregnancy.

Time frame
From enrollment until birth.

Secondary outcomes

1

Secondary outcome measures

A composite outcome of all-cause mortality rate according to gestational age and maternal valve thrombosis rate

Time frame
From enrollment until 12 weeks postpartum

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Mount Sinai Hospital, Canada

Lead sponsor

Source ClinicalTrials.gov
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