Pregnancy: The Cardiac Stress Test You Can't Ignore

Michelle L. O'Donoghue, MD, MPH; Rachel M. Bond, MD


March 22, 2023

This transcript has been edited for clarity.

Michelle L. O'Donoghue, MD, MPH: Hi. This is Dr Michelle O'Donoghue, reporting for Medscape. Joining me today is Dr Rachel Bond. She is the systems director for women's cardiovascular health at Dignity Health in Arizona. Thanks for joining me today, Rachel.

Rachel M. Bond, MD: Thank you so much. It's a pleasure to be here.

Pregnancy-Related Risk Factors

O'Donoghue: At this conference, you're going to be talking about the issue of cardio-obstetrics. I'm so glad that this topic is finally getting the attention that it deserves because for far too long, we have not been incorporating obstetrics into a woman's cardiovascular history. Really, it should play a key part.

What are your thoughts about what doctors should be asking patients when they're trying to understand what their cardiovascular risk factors are?

Bond: You're absolutely right, that it's such an exciting time in the world of cardio-obstetrics. I would say, particularly this year, it's so timely with us realizing that cardiovascular disease occurs across the lifespan. We know that a key part during a woman's age is reproductive health, if they do decide to have a child.

With that being said, when it comes to us as cardiologists, in addition to the traditional history that we take, which looks at those traditional risk factors like high blood pressure, high cholesterol, diabetes, and smoking history — things that disproportionately impact more women than men, as an example — we also have to think about cardio-obstetrics and the reproductive health of that particular patient.

During their pregnancy, did they have gestational diabetes; gestational hypertension; or other hypertensive disorders of pregnancy, such as chronic hypertension, meaning blood pressure being diagnosed prior to 20 weeks' gestation; or even preeclampsia? We even know that premature labor and having a child smaller than gestational age are independent risk factors for cardiovascular disease.

We're noticing that it can actually impact a woman's health about 20 to even sometimes 40 years after their delivery. It's such an important part for us, if we're going to really think about caring for the patient as a whole, to incorporate that standardly into the medical history.

Changes at the Level of the Endothelium

O'Donoghue: You made many great points. I think one of them is that they do appear to be independent risk factors for developing cardiovascular disease. I emphasize that because I think there has been the misconception that you don't really need to ask people about a history of gestational diabetes or preeclampsia because those same individuals already have cardiovascular risk factors that you'd be identifying otherwise.

Once you ask somebody if they've ever had a diagnosis of high blood pressure, then you're covered. I think we're beginning to understand that during the pregnancy, there might be actual biological changes that occur for people who have these complications that then put them at higher risk of developing cardiovascular disease down the road. Tell us a little bit more about that.

Bond: You bring up a very valid point that, although women that have these higher traditional risk factors are more likely to get those adverse pregnancy outcomes; we know that in a subset of the population, you may not necessarily have those traditional risk factors, like diabetes, high cholesterol, or even high blood pressure.

Before I delve deeper into the independent risk factors and the pathophysiology behind that, I do think it's important to highlight that among adults of reproductive age, less than 1% have ideal cardiovascular health. This is why there is a misconception that most people who are going to have adverse pregnancy outcomes are coming into the pregnancies with lack of ideal cardiovascular health. As noted, we know that those risk factors could occur with or without ideal cardiovascular health.

As such, we are trying to figure out the underlying pathophysiology. Although it's very complex and complicated, we know that it is at the level of the endothelium. With pregnancy, independently, it is its own stress test, right? We think about pregnancy as a cardiac stress test and we know that the changes that occur during pregnancy, just with stroke volume, cardiac output, heart rate, and blood pressure, for example, all of that could sometimes unmask at the level of the endothelium, underlining conditions and underlining disease.

That can actually continue on into the entirety of decades, even multiple decades later. We are really trying to emphasize that these are risk factors that are independent of those more traditional risk factors, even though those more traditional risk factors put women at a higher risk of having these adverse pregnancy outcomes.

O'Donoghue: I think it's such an interesting concept that pregnancy is the early cardiac stress test and really may unmask future problems down the road. From a personal angle, I developed gestational diabetes despite the fact that I think I'm probably the world's healthiest eater. I at least fancied myself as being exceedingly low risk of developing that type of complication, but it has made me more aware as a consequence.

If somebody is diagnosed during their pregnancy with one of these complications that we're discussing, what is the next step?

Do you think that they should be more rigorously followed? Do you advocate earlier initiation of statin therapy? How should doctors think about this?

Bond: Right now, we are looking for more research that's focused on this area because although our assumption is that we need to be more rigorous, we don't have guidelines. What we have are statements that give us suggestions on what that path should look like.

As an example, anybody who's had an adverse pregnancy outcome, at a minimum, should be screened for cardiometabolic risk factors at least 3 months after the delivery, possibly longer than that, depending on the patient. The recommendation is that screening should occur within that 3-month window, where we would be vigorously looking at the traditional risk factors that we can modify, like blood pressure, cholesterol, and diabetes risk, and really counseling them on healthy eating habits, exercise, and all the things that we typically would for the traditional risk factors.

More importantly, we now know that many studies are looking to see if we should be adding additional risk enhancers, such as biomarkers that can give us a better idea if the risk is higher, or even the utilization of a calcium score, as an example. Should we be screening these women later in the future with calcium scores? Do we already see that they're subclinical evidence of cardiovascular disease?

There was a large trial that showed that women with preeclampsia had a much greater burden of subclinical calcium calcification in the coronary arteries around the age of 45 years than did those with normotensive pregnancies. With that being said, it gives us an opportunity to say that we probably should be more vigorous in terms of not only screening these patients but possibly also initiating preventive measures, such as guideline recommendations for statin therapy and others, to help reduce their risk for cardiovascular disease, and more importantly, their burden of cardiovascular disease.

Whose Job Is It: Ob/Gyn, Primary Care, Cardiology?

O'Donoghue: I think, all too often, people fall through the cracks. There are many women who in fact don't even have a primary care doctor and they view their gynecologist or their obstetrician as their healthcare provider. Whose responsibility is it? I think once the baby is born, very often, you have your final visit with the obstetrician, and then I feel that there is opportunity for people to fall through the cracks at that point in time.

Bond: That is the concern, the gaps in care. We are really trying to change the way medicine has been practiced in the past, which is more siloed, and really allow for that collaboration. You're absolutely right to say the obstetrician/gynecologist tends to be the primary care clinician during the reproductive years.

There is a large amount of education that will be targeting the obstetricians. In an effort to also ensure that there's longevity in the screening, we really do need to ensure that they are handing that patient over to the primary care clinician and possibly even cardiology, if cardiologists do need to be involved. That's really at the discretion of the patient's individual risk.

It's important for primary care clinicians out there to realize that these cardiometabolic screenings are the basic screenings that we should be doing. Guideline suggest that for patients typically starting at the age of 20 years, but even when we are calculating their atherosclerotic cardiovascular risk calculator, standardly 40 years and above.

As such, we have to think about these independent risk factors, these adverse pregnancy outcomes, the same way we think about the traditional risk factors. If you do that, it does make it easier. The importance is in ensuring they have a primary care clinician, and that's where that handoff from the obstetrician/gynecologist to that primary care clinician is so key.

O'Donoghue: It really is a shared responsibility. Thank you so much for shining a spotlight on this topic.

As a final note for those who are watching, what would be the quick checklist, again, for the questions to ask if you have a woman coming in and you're thinking about cardiovascular risk prevention? What are the specific pregnancy complications?

Bond: In addition to screening for those traditional risk factors that we discussed, we want to think about if they did have a child, did they have any of those adverse pregnancy outcomes, such as the gestational diabetes, gestational hypertension, chronic hypertension, preeclampsia, premature labor that was unexplained, and more importantly, a child that was smaller than gestational age? Incorporating that into the history will go a long way because it will absolutely give us a better understanding of what their true risks are.

Then, when we do the cardiometabolic screening, we can determine if we want to do additional tests, such as those biomarkers or those risk enhancers that are laboratory tests, or even a calcium score, as an example, which at a minimum, will give us usually a good idea as to what their cardiovascular health is right now.

Then, of course, it will also allow us to determine how aggressive we need to be in the management. Is it lifestyle only? Is there a role for additional guideline-based medical therapy to lower their chances of having a poor cardiovascular outcome?

O'Donoghue: Thank you. That's terrific. I just hope that we can get to a point that this becomes a standard part of our questioning. Thanks again for joining me today.

Bond: Thank you. It was a pleasure.

O'Donoghue: Signing off for Medscape, this is Dr Michelle O'Donoghue.

Michelle O'Donoghue is a cardiologist at Brigham and Women's Hospital and senior investigator with the TIMI Study Group. A strong believer in evidence-based medicine, she relishes discussions about the published literature. A native Canadian, Michelle loves spending time outdoors with her family but admits with shame that she's never strapped on hockey skates.

Follow | Medscape Cardiology on Twitter

Follow Medscape on FacebookTwitterInstagram, and YouTube


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.