Mom’s Cardiovascular Risk After Pre-Eclampsia Emerges Within a Decade

It did not take long after pregnancy for excess heart attacks and strokes to emerge in women with pre-eclampsia, according to national records from Denmark.

Within 20 years of delivery, the cumulative incidence of acute myocardial infarction (MI) and ischemic stroke approached 2.0% in women who had a history of pre-eclampsia versus 1.2% who had no pre-eclampsia, reported Sara Hallum, MSc, a PhD student and epidemiologist at the University of Copenhagen, and colleagues.

This between-group difference in hard outcomes was apparent by 7 years after delivery — particularly among women whose first pregnancy occurred at or after 35 years of age — and was generally most prominent within 10 years of delivery.

After 10 years, women with pre-eclampsia remained at a several-fold higher risk of acute MI (HR 4.16, 95% CI 3.16-5.49) and stroke (HR 2.59, 95% CI 2.04-3.28). The risk remained doubled at year 20 and beyond, Hallum’s group reported in the European Journal of Preventive Cardiology.

“Collectively, our study indicates that women with a history of pre-eclampsia have considerable cardiovascular morbidity at early ages and within a decade of delivery,” they wrote.

“This indicates that interventions to prevent heart attacks and strokes in affected women cannot wait until middle age when they become eligible for conventional cardiovascular screening programs,” Hallum explained in a press release.

The guidelines currently differ regarding postpartum cardiovascular disease (CVD) risk assessment for women with a history of pre-eclampsia. The International Society for the Study of Hypertension in Pregnancy recommends counseling these women about their risk and monitoring their blood pressure (BP) regularly, whereas the European Society of Cardiology do not recommend a separate risk assessment for this population.

Given that screening would entail following a large number of women with a history of pre-eclampsia over years or even decades, the authors suggested narrowing down the subgroups most likely to benefit from CVD screening.

To that end, they reported that women who had pre-eclampsia after age 35, pre-eclampsia in a second pregnancy, and pre-term pre-eclampsia were at particularly high risk of acute MI and ischemic stroke.

Key features of pre-eclampsia are high BP and protein in the urine developing after 20 weeks of pregnancy or soon after delivery.

“Women may mistake these for ‘normal’ pregnancy symptoms and thus not seek medical help until the condition becomes severe,” said Hallum. “Most cases are mild, but pre-eclampsia may lead to serious complications for the mother and baby if not treated in time.”

“Prevention should start within a decade of delivery, for example by treating high blood pressure and informing women about risk factors for heart disease such as smoking and inactivity,” she urged.

For the present study, Hallum’s team relied on prospective Danish registries. They identified over 1 million women who were pregnant from 1978 to 2017 and had been free of cardiovascular disease before pregnancy.

Over a median 20.5 years of follow-up, 2.5% of women had an acute MI as their first ischemic event, while 3.8% had an ischemic stroke.

“Some women who had acute MIs or strokes within the first decade of delivery may have had clinically undetected CVD before pregnancy. However, from a clinical perspective, whether pre-eclampsia pre-dated CVD, or vice versa, is of minor importance,” the study authors noted.

“Regardless of the mechanism, women who had pre-eclampsia had much higher risks of hard ischemic endpoints within the first decades after delivery and at young ages than women without a history of pre-eclampsia,” they continued.

Future work is needed to clarify whether screening will help women with a history of pre-eclampsia, along with the questions of when to do it and in whom.

Hallum’s group cited ongoing trials that are testing whether targeted interventions, initiated soon after pregnancy with pre-eclampsia, mitigate arterial stiffness and BP change. “The next step will then be to determine whether the CVD risk factor mitigation produced by such targeted interventions translates into a reduction in adverse cardiovascular outcomes among women with a history of pre-eclampsia,” they wrote.