COMMENTARY

ESC Guidelines on Pregnancy in Women With CVD: What's New?

Marie-Christine Malergue, MD; Claire Bouleti, MD

Disclosures

February 28, 2019

Editor's Note:
The following is an edited translation of a discussion recorded for Medscape French Edition at Journées Européennes de la Société Française de Cardiologie (JESFC), the annual European meeting of the French Society of Cardiology.

Marie-Christine Malergue, MD

Marie-Christine Malergue, MD: I am Marie-Christine Malergue, a cardiologist and echocardiographer at the Institut Coeur Effort Santé in Paris. I am happy to be joined by Claire Bouleti, a cardiologist at the Bichat hospital. We both participated in a session at JESFC on cardiomyopathies in pregnant women.

The European Society of Cardiology (ESC) released guidelines in 2011[1] on the management of cardiovascular disease (CVD) during pregnancy, and in 2018, they updated these recommendations.[2] Claire, what are the major changes since the previous recommendations?

mWHO Classification of Maternal Risk 

Claire Bouleti, MD

Claire Bouleti, MD: The main difference is that the new guidelines emphasize the modified World Health Organization (mWHO) classification of maternal cardiovascular risk, which has four classes and five categories of risk (there is an intermediate risk category, mWHO II-III).

This modified WHO classification is easy to use. There is a summary table in the ESC guidelines that specifies the follow-up procedures that are necessary and whether the local hospital or an expert center should handle the patient, so it is very practical.

Malergue: When a patient with CVD mentions that she is planning to get pregnant, the cardiologist should do a risk assessment based on the pathology, and discuss the risks with the patient.

Bouleti: Absolutely. In fact, that is a class I recommendation, so the highest level. One of the changes from the 2011 recommendations is that it's more clearly recommended that you use the mWHO classification for this risk assessment.

There are a number of other changes. Another recommendation that moved to class I concerns the rheumatic valvulopathies. Patients who have a tight mitral stenosis with a surface < 1 cm² should undergo intervention before their pregnancy, which should preferably be a percutaneous mitral commissurotomy.

Anticoagulation Management

Malergue: We do not have many de novo rheumatic valvulopathies, but there are women who have old rheumatic valve problems.

What about women with mechanical valves on long-term anticoagulation who want to have a child? How should they be managed during the pregnancy? I have always been told that vitamin K antagonists (VKAs) are teratogenic and should not be used in the first trimester. Is that still true?

Bouleti: There is indeed a risk for embryopathy related to the use of VKAs during the first trimester. However, this risk is counterbalanced by the reduction in maternal thromboembolic risk. The risk for thromboembolism is much lower with VKA compared with the heparins, whether that's unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH).

Remember that when we put in a mechanical valve, we typically tell the patient that pregnancy is contraindicated, so this should be a rare case.

Malergue: More patient education is needed.

Bouleti: Exactly. We can approach each case according to the VKA dose. For example, if a low dose is needed to obtain the therapeutic international normalized ratio (INR)—a low dose is < 5 mg/day of warfarin (Coumadin), < 3 mg/day of phenprocoumon, or < 2 mg/day of acenocoumarol—it's advised to use VKA for the whole pregnancy, including the first trimester.

For the second and third trimesters, it's a class I recommendation to use VKA up to 36 weeks, and then switch to heparin (LMWH or UFH) and intravenous (IV) UFH is given 36 hours before the scheduled delivery. This IV heparin is stopped 4-6 hours before delivery and resumed (in the absence of bleeding complications) within 4-6 hours after delivery.

The risk for embryopathy is much lower with low-dose VKAs, which is why the ESC guidelines recommended VKAs as the first choice. It's a class IIa recommendation to use in the first trimester and the use of heparins is class IIb, so we are rather in favor of VKAs during pregnancy in these patients.

Heparin Switch

Malergue: What about the bleeding risk (especially cerebral) to the fetus with VKA? Does it cross the placenta during delivery?  

Bouleti: Vaginal delivery is usually contraindicated in a patient on VKA because of the risk for cerebral hemorrhage of the fetus. VKA anticoagulation is extremely long-lasting in the fetus—it's present more than 2 weeks after stopping therapy in the mother—so that is the reason for the switch to heparin. Even if you have to schedule a cesarean delivery at 38 or 39 weeks or you plan a natural vaginal delivery at term, there will be time during the 2 weeks for the VKA to disappear from the fetal system.

Malergue: As the guidelines note, patients must be admitted to hospital to manage the switch to heparin, and they must be educated and referred to specialized centers for high-risk pregnancies.

Coming back to rheumatic cases, you still see a lot at Bichat hospital, but they are on the decline, at least in most Western countries.

Bouleti: Yes. We're a little biased because we see so many young patients who are affected.

Malergue: Increasingly, there are patients with extremely serious congenital heart defects that have been repaired who reach adulthood and now want to get pregnant. This area needs more study, but they should undergo echocardiography to assess risk and help advise them.

Some of these women are older and can have an accumulation of risk factors (such as a history of smoking). It is great that medical advances have allowed them to survive to adulthood, but now we are dealing with women at much higher risk than we used to see.

Bouleti: This is why it's so important to precisely stratify maternal risk using the mWHO classification.

Malergue: We should also note that all of these recommendations are level of evidence C, because obviously there are no randomized controlled trials in this area. In the ESC guidelines, the life of the mother is prioritized in relation to the life of the fetus.

Bouleti: Yes. This is a feature of these recommendations, and we see this in the discussion of anticoagulation where the reduction of thromboembolic risk in women with artificial valves is favored at the expense of an increased risk for potential embryopathy, especially with VKA.

There are patients who tell us very clearly that if there are counterbalancing risks that they would prefer to take the risk over their child. After you've fully explained the risks, we must of course respect the choice of the mother.

Malergue: Let's now discuss the delivery. Can women with cardiomyopathies have an epidural?

Bouleti: In women with mechanical valves (especially the mitral valve), the epidural is formally contraindicated because of the need to stop anticoagulants. The heparin must be stopped the day before the delivery. Epidural anesthesia usually prolongs the delivery, and this exposes the patient to a greater risk for thrombosis; that is why the epidural is contraindicated in these patients.

HCM and Pregnancy

Malergue: At the JESFC session, we discussed women with hypertrophic cardiomyopathy (HCM), which is not uncommon. What are the important management issues?

Bouleti: It is a pathology that is indeed far from rare; however, we have only a few very recent studies on pregnancy in women with HCM.

The ESC-initiated Registry of Pregnancy and Cardiac Disease[3] identified only 60 patients who had HCM—25 had obstructive HCM with a left ventricular outflow tract pressure gradient > 30 mm Hg—and the risk for events in this series was 23%, so not negligible. Obviously, this was a composite endpoint of major cardiovascular events; there were no maternal deaths or embolic pathologies. What we did see was heart failure, ventricular arrhythmias, and some atrial fibrillation. So in general, they did well.

Malergue: How should we treat these women, what type of beta-blockers should be prescribed, and why?

Bouleti: The guidelines recommend that it is better to use beta-1–selective beta-blockers, in particular metoprolol and bisoprolol, which compared with other beta-blockers have a slightly lower risk of interfering with uterine contraction and thus a reduced risk for fetal growth restriction and premature delivery.

There are other selective beta-1 beta-blockers, such as atenolol, are not recommended, as they seem to cause more intrauterine growth restriction.

Malergue: Would you agree that pregnancy is not contraindicated in a woman who has controlled HCM (ie, well beta-blocked) without a gradient at rest?

Bouleti: Yes, I would agree that pregnancy is not contraindicated.

Malergue: You have to follow these patients carefully. If such a patient tells you she would like to get pregnant, do you perform a stress echo, or any other specific tests to assess her risk during pregnancy and childbirth?

Bouleti: There are no clear recommendations. In an asymptomatic patient who is well beta-blocked, we should try to stratify risk through stress testing. The challenge is that the physiologic changes in pregnancy, such as increased cardiac output, can hardly be reproduced by a standard stress test. This is one of the limits. But, having said that and even though it's not clearly recommended, I think it can be helpful.

Malergue: Thank you for joining me today.

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