Research Clarifies Link Between BP Problems in Pregnancy and Later CVD

Women with a history of hypertensive disorders of pregnancy (HDP) have a 2.4-fold higher risk of developing hypertension within 10 years, according to new data from a largely Black cohort of women. However, their long-term CVD risk seems to be more closely related to the development of hypertension than it is to the HDP history.

Plenty of evidence already suggests a strong link between HDP, like gestational hypertension and preeclampsia, and CVD risk later in life, but other research points to the likely underappreciation of this relationship, particularly in minority populations who have typically been underrepresented in these studies.

“More than anything, one take-home point is just a reminder that adverse pregnancy outcomes, preeclampsia experiences that occur during pregnancy, can impact patient's future cardiovascular health,” lead author Lisa Levine, MD (University of Pennsylvania Perelman School of Medicine, Philadelphia), told TCTMD. “And so asking about pregnancy complications is hugely important [as is] ensuring that they are getting screened and getting in for those appointments: blood pressures monitored, lipids assessed, lifestyle modification, and things like that.”

Commenting on the study for TCTMD, Michael C. Honigberg, MD (Massachusetts General Hospital and Harvard Medical School, Boston, MA), said it “reaffirms prior data, but in a historically understudied population, that women who experience hypertensive disorders of pregnancy are at substantially higher risk for progression to chronic hypertension [and importantly] stage 2 hypertension, sort of real-deal hypertension. . . . [This is] the single most important thing to target for long-term risk reduction in women who have hypertensive disorders of pregnancy.”

The findings, he continued, stress the importance of physicians being “much more aggressive and intentional about targeting these women, both preconception before they get pregnant, but then also especially once they've declared themselves as being high risk on the basis of hypertensive complication with aggressive primordial and primary prevention strategies to reduce this long-term cardiometabolic risk.”

2.4-Fold Higher Risk

For the study, published in the June 21, 2022, issue of the Journal of the American College of Cardiology, Levine and colleagues prospectively included 84 women with and 51 without a history of HDP from a prior postpregnancy study who completed additional blood work, physical exams, surveys, and echocardiograms. In total, 85% of the population self-identified as Black, and 50% of the cohort had obesity.

Over 10 years, patients with a history of HDP had more than double the risk of new hypertension—so-called stage 2 chronic hypertension—compared with controls, even after adjustment for race, maternal age, body mass index, and history of preterm birth (56.0% vs 23.5%; adjusted RR 2.4; 95% CI 1.39-4.14). Importantly, 18% of patients with a history of HDP had their new hypertension diagnosed at the time of the study visit.

Levine explained that she was originally surprised by these results because “all of us really, really believed that there were going to be more cardiovascular differences, besides just hypertension.” Other studies in predominantly white populations have suggested that “there might be some hint of echocardiographic differences and endothelial dysfunction differences in patients with and without a history of hypertension,” she said. “I think perhaps ours was different because it was a little bit further out from the episode of preeclampsia.” Additionally, she noted the high-risk population of the study may have led to worse outcomes overall.

“But even with that said, I think most of us that were involved in the study really thought there was going be some gleam or glimmer of a difference between the two groups, and I think we were all really surprised that aside from the difference in hypertension rates, which we weren't surprised about, that there really were no other differences,” Levine continued.

That’s part of the reason why the authors performed a number of exploratory analyses, Levine said. Here, they found, patients with chronic hypertension were notably different from patients without, regardless of HDP status, in that they had greater LV remodeling, including higher intraventricular septum, posterior wall, and relative wall thickness (P < 0.001 for all). Patients who developed chronic hypertension also showed worse diastolic function, including lower septal e’ (P < 0.01) and lateral e’ (P = 0.03) and E/A ratio (P = 0.02); more abnormal global longitudinal strain (P = 0.02); and higher effective arterial elastance (P = 0.03).

“It comes down to the high prevalence of hypertension in this population and the fact that it probably is hypertension in and of itself that drives the differences in all of those other parameters,” Levine speculated. “I think it actually makes quite a bit of sense that it's really hypertensive disorders of pregnancy that increase your risk of developing hypertension and it's that hypertension that increases your risk of future heart disease. Perhaps the unappreciated prevalence of hypertension in this population is also what mediates some of the future risk, especially in marginalized patients.”

Improving Postpartum Care

In an accompanying editorial, Josephine C. Chou, MD (Yale University School of Medicine, New Haven, CT), writes that the findings support the fact that “the initial postpartum years offer a window of opportunity to impact lifelong CV health, with ample evidence supporting chronic hypertension as the most important condition to target for reducing CVD in patients with HDP.”

However, she notes, the lack of continued care in patients with HDP for a variety of reasons leads to “frequently missed” opportunities. Some solutions include postpartum transitional clinics, remote monitoring, standard postpartum care guidelines, and Medicaid expansion, Chou suggests.

“Progress is being made to improve postpartum care, but as long as these barriers exist, they exacerbate health inequities which already burden high-risk populations,” she writes. “Black patients are known to be disproportionately affected by HDP and their complications. However, it is important to recognize race as a social construct, and not an inherent risk factor for disease. Therefore, addressing these disparities requires an understanding of the distinct CV profiles and sociodemographic factors that contribute to HDP and CVD in Black patients.”

Honigberg confirmed that “a lot of the seminal work in cardio-obstetrics, including preeclampsia epidemiology and the links between preeclampsia and cardiovascular disease, have historically been conducted in largely white or European ancestry populations. . . . The reasons are complex and multifaceted for why we have historically underrepresented women of color from these pregnancy focused studies.”

Therefore, he lauded Levine and colleagues for what they were able to accomplish with this study. “We think of these pregnancy complications as sort of a ‘stress test’ for future cardiovascular disease, and I think historically, we've really thought about that from a purely innate biology standpoint,” he said. “But I think what it also highlights is maybe we should be thinking about it as an even broader stress test for other sorts of risk like social risk and social determinants of health.”

On top of looking into ways to make lifestyle modification easier for new parents, Honigberg also said he’d like to see more research to learn “the fundamental underlying biology better to understand what specifically it is about these women is that is predisposing [them] to chronic hypertension,” so as to be able to target that with either specific lifestyle changes or pharmacotherapy. Policy changes are also needed to address overall cardiometabolic health, “because I think in a sense these pregnancy complications are reflecting these broader concerning trends,” he added.