Clinical Trial Details
— Status: Active, not recruiting
Administrative data
NCT number |
NCT05108389 |
Other study ID # |
19OB011 |
Secondary ID |
|
Status |
Active, not recruiting |
Phase |
|
First received |
|
Last updated |
|
Start date |
March 1, 2022 |
Est. completion date |
October 1, 2023 |
Study information
Verified date |
April 2023 |
Source |
Nottingham University Hospitals NHS Trust |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
There is a lack of consensus on whether women with proteinuric kidney disease benefit from
prophylactic anticoagulation during pregnancy to reduce the risk of venous thromboembolism.
This pilot study will investigate the feasibility of obtaining thrombosis profile data using
a viscoelastic haemostasis monitor - Sonoclot - from pregnant women with kidney disease, and
exploratory analyses to elucidate correlations between output values and clinical parameters
Description:
Pregnancy is a risk factor for women developing blood clots in veins (VTE). The risk is
highest towards the end of pregnancy and in the few weeks following delivery. VTE can cause
swollen painful legs due to clots in the deep veins (DVT) and/or blood clots in the lung
vessels leading to chest pain, breathlessness and loss of blood pressure. VTE is the leading
direct cause of death in pregnant women in the UK (affecting 1.4 per 100,000 pregnancies).
Additional risk factors for VTE (including obesity, family history, previous history of blood
clots and Caesarean section) are routinely valuated through standard care and treatment to
thin blood with low molecular weight heparin (LWMH) injections is offered to those at highest
risk. Women with kidney disease comprise a very small proportion of all pregnancies and are
hence under-represented in large-scale studies to evaluate VTE risk.
Outside of pregnancy, patients with kidney conditions associated with heavy leakage of
protein into urine through damaged microscopic filters (glomeruli) plus low blood protein
plus swelling (the "nephrotic syndrome") have an increased risk of VTE. VTE risk is increased
as a result of (a) concentration of blood within blood vessels due to fluid leak into
tissues, (b) decreased flow of blood through veins due to circulating volume and decreased
mobility and (c) an imbalanced loss of proteins in urine that favour or inhibit blood
clotting. There is evidence to support blood thinning treatment to reduce the risk of VTE in
patients with one cause of nephrotic syndrome - membranous nephropathy - and many clinicians
choose to offer blood thinning treatment to patients with other causes of nephrotic syndrome
if they believe the patient is at increased risk of clots.
There are no clinical data to confirm a benefit of blood thinning treatments to prevent VTE
in pregnant women with nephrotic syndrome, but, faced with the lack of published studies,
consensus guidelines published in 2018 recommend that women with nephrotic syndrome should be
treated during pregnancy and for 6 weeks after birth.
There is a lack of consensus on whether women with less severe protein leak during pregnancy
should be offered blood thinning injections. An international survey of clinicians caring for
women with these conditions reports a wide range in practice from some offering treatment to
all with a protein leak (urine protein:creatinine ratio) >100mg/mmol, to others only
considering treatment if leak was >300mg/mmol AND evidence of low blood protein AND swelling.
VTE prophylaxis with LMWH is standard of care for medical in-patients and for out-patient
treatment in pregnant women identified to be at increased VTE risk. Although LMWH treatment
is not associated with any adverse pregnancy outcomes, it is uncomfortable, inconvenient and
can interfere with delivery plans if spinal or epidural anesthetic is required.
There are, therefore, women receiving LMWH prophylaxis because of increased urine protein
leak despite inadequate evidence to prove the benefit of this strategy and insufficient
clinical tools to triage risk profiles for these patients.
There are no routine laboratory tests that offer a direct measurement of thrombotic risk.
Sonoclot is established technology that has been utilised to quantify bleeding risk after
cardiac surgery and disseminated clotting abnormalities, and adequacy of anticoagulation in
haemodialysis patients and during treatment with direct acting oral anticoagulants. In
addition to predicting bleeding risk, results also identify clotting risk. This has
previously been studied in women taking oral contraception and in normal pregnancy with both
identifying patterns consistent with increased thrombotic risk during pregnancy or with
combined oral contraceptive use.
This study aims to assess the feasibility of conducting a clinical trial using Sonoclot
results to identify which pregnant women with kidney disease are at increased risk of VTE and
which are not, to define treatment protocols with LMWH prophlyaxis. This pilot study will
assess the correlations between Sonoclot results, urine protein leak, gestational age,
routine laboratory test results and routine VTE risk assessment tools.