HDiP - MCAFO
Research type
Research Study
Full title
Heart Disease in Pregnancy - Maternal Cardiovascular Adaptation and Fetal Outcomes
IRAS ID
222431
Contact name
Francois Dos Santos
Contact email
Sponsor organisation
Imperial College London
Duration of Study in the UK
1 years, 6 months, 0 days
Research summary
Heart disease in pregnancy is the single largest cause of indirect maternal deaths in the UK. The high maternal mortality rate due to heart disease remained unchanged from 2009-2013 and addressing it remains a major challenge for the UK health service.
The number and disease complexity of congenital heart disease survivors continues to grow and obstetricians need to be able to manage such women safely. In low-risk pregnancies, the cardiovascular system (the heart and the vessel network of the body) undergoes a series of physiological changes to meet the increased metabolic demands of the mother and the fetus. There are limited data on the adaptation of the heart in women with congenital heart disease and little is known about the reversibility of these changes after pregnancy. Research in this field is therefore of high priority.
Women with congenital heart disease are also known to deliver small babies. It is yet to be established if this is a consequence of poor adaptation of the cardiovascular system to pregnancy or if there is an underlying problem with the placenta caused by the heart disease itself.
Our aim is to study the adaptation of the cardiovascular system to pregnancy in women with congenital heart disease but also in women without any heart disease and in women whose babies are found to be small during pregnancy.
To do this, we plan to see the three groups of women at different points of their pregnancy and check their blood pressure and saturations and perform a scan and a reading of their heart using electrodes. These tests would be conducted at rest and after a short period of exercise on a stationary bike. We would also perform scans of their babies to monitor the growth and blood flow and take blood samples and samples from the placenta after birth.
Summary of Results:
Introduction The number of pregnant women with congenital heart disease (CHD) is increasing. Validation of non-invasive techniques to monitor cardiac output (CO – which is the amount of blood the heart pumos at each minute) in this population is needed. Uteroplacental blood flow (blood flow in the placenta and uterus) which is compromised in women with CHD, is associated with their cardiac function. B-type natriuretic peptide (BNP), cytokines and cellular adhesion molecules (CAMs) are all present in the bloodstream and markers of how the heart is working. Measuring these in the blood could provide insight into the higher adverse pregnancy/cardiovascular events in women with CHD.
Methods
Low-risk pregnant women (LR-group) and pregnant women with CHD (CHD-group) were seen in each trimester of pregnancy. We recruited 151 pregnant women. Some were seen in the three trimesters of pregnancy and others were only seen once or twice. Visits included blood sampling for BNP, cytokine/CAM analyses and measurement of haemodynamic parameters (parameters of blood circulation) at T1-rest, T2-immediately after exercise and T3-after recovery, simultaneously with transthoracic echocardiography (TTE) and impedance cardiography (PhysioFlow®). Fetal growth and Doppler studies performed in the third trimester.Results
PhysioFlow® showed good trending ability (LR-group: concordance rate-CR=95.4%, angular bias=4.5o; CHD-group: CR=100%, angular bias=4.1o). Their blood pressure profile followed a J-shape pattern, heart rate increased, peripheral oxygen saturations decreased and CO remained stable with advancing gestation. No association found between uterine artery Doppler and CO/ΔCO or mean arterial pressure in either group. Umbilical artery Doppler was negatively associated with birthweight (BW-p=0.004, BW centile-p=0.006), as was the cerebroplacental ratio (BW-p=0.002, BW centile-p=0.003) in the LR-group. BNP decreased throughout pregnancy, without significant differences between groups. IL-6 was higher in the CHD-group (p=0.005) in the first trimester, IL-10 lower in the third trimester (p=0.018). High levels of IL-6 in the first trimester were associated with lower BW (p=0.002, BW centiles-p=0.020). Higher ICAM in the CHD-group in the first trimester was associated with lower BW (p=0.002, BW centiles-p=0.006).Conclusion
PhysioFlow® can be used in low-risk pregnancy to study trends in CO. This is particularly helpful as physioflow is non-invasive (meaning that it collects information simply by applying some stickers to the skin which are connected to cables and a reader) and is easy to use. This means that these parameters can be easily measured when there is a concern. BNP decreased throughout pregnancy in both groups. The proinflammatory cytokine profile in women with CHD could explain the higher incidence of adverse outcomes, although more research is needed.REC name
London - South East Research Ethics Committee
REC reference
17/LO/0970
Date of REC Opinion
29 Jun 2017
REC opinion
Favourable Opinion