Women with preeclampsia have a higher likelihood of heart attack and stroke than their counterparts within just 7 years of delivery, with risks remaining elevated more than 20 years later.  These are the results of a study conducted in more than a million pregnant Danish women released last month in the journal European Journal of Preventive Cardiology.

The heart disease linkage

According to previous research conducted by Seely and colleagues (J Women’s Health. 2021) pregnancy complications are unique risk markers for cardiovascular disease (CVD) in women.  Preeclampsia, which occurs in 2% to 8% of pregnancies, is the complication most strongly and consistently related to future CVD.  In fact, women with a history of preeclampsia experience twice the rate of CVD events, a 2.2-fold increased rate of chronic hypertension, 80% increased rate of type 2 diabetes, and 30% increased rate of elevated cholesterol compared with women with normotensive pregnancies (Stewart et al. 2018).

During Leon and colleagues’ 20-year study period 18,624 incident cardiovascular disorders were observed in a cohort of UK-based women, 65% of which occurred in women <40 years.  Even higher risks of CVD were noted in women with recurrent episodes of preeclampsia or preterm preeclampsia (Leon et al. 2019).

Despite this evidence in the literature that preeclampsia predisposes women to an elevated likelihood of CVD later in life, the researchers of the new Danish study, conducted by a team from University of Copenhagen; Bispebjerg-Frederiksberg University Hospital; and Statens Serum Institut, Copenhagen, Denmark, contend that theirs was the first study to explore how soon after pregnancy these heart attacks and strokes manifest, and the magnitude of risk in different age groups.

 The 7-year risk difference window

National registers were used to identify all pregnant women in Denmark between 1978 and 2017.  The study included 1,157,666 women who were grouped into those with 1 or more pregnancies complicated by preeclampsia and those with no preeclampsia.  Participants were free of CVD before pregnancy and were followed for a maximum of 39 years for heart attack and stroke.

Up to 2% of those with preeclampsia in their first pregnancy experienced a heart attack or stroke within 2 decades of delivery, compared with up to 1.2% of unaffected women.  Differences in risk became apparent 7 years after delivery.

A 4-fold risk which persists

Overall, women with preeclampsia were 4 times more likely to have a heart attack and 3 times more likely to have a stroke within 10 years of delivery than those patients who did not experience preeclampsia.  The risk of heart attack or stroke remained twice as high in the preeclampsia group more than 20 years post-delivery compared to unaffected women.

The age aspect

When the researchers examined the risk of CVD according to age, they found that women aged 30 to 39 years with a history of preeclampsia had 5- and 3-fold higher rates of heart attack and stroke, respectively, than those of similar age with no history of preeclampsia.  The raised likelihood of CVD in study subjects with a history of preeclampsia persisted throughout adulthood, with women over 50 years of age still at doubled risk compared to their peers who had no history of the pregnancy complication.

Further, the study suggests that having preeclampsia in the second pregnancy—but not the first—was more strongly associated with heart attack risk than experiencing preeclampsia in the first but not the second pregnancy.

The researchers note that this result counters the premise that an increased risk of heart attack is associated solely with preeclampsia itself.  Instead, they conjecture that other factors, such as the excessive demands placed on the heart during subsequent pregnancies complicated by preeclampsia may play a role.

Guidance for women’s health practitioners

The study findings suggest that preeclampsia history could be useful to providers in identifying women at increased risk of CVD and that targeted interventions should be initiated soon after delivery.

“Women are often in contact with the healthcare system during and immediately after pregnancy, providing a window of opportunity to identify those at increased risk of cardiovascular disease,” noted study author Dr. Sara Hallum in a press release accompanying study publication.

“The number of women with previous preeclampsia is large, and routine follow-up could last years or even decades.  Our study suggests that the women most likely to benefit from screening are those who had preeclampsia after age 35 and those who had it more than once.  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.”

All of Hallum and colleagues’ findings from “Risk and trajectory of premature ischaemic cardiovascular disease in women with a history of preeclampsia: a nationwide register-based study,” is available at no cost here.

Clinicians’ Bonus:  More To Know

Resources for you and your patients

 For You

The US-based Preeclampsia Foundation published an updated position paper in July 2020 for clinicians, “Preeclampsia and Future Cardiovascular Disease in Women: What Do We Know and What Can We Do?”  This comprehensive 25-page document summarizes current research findings and provides best practice recommendations related to preeclampsia and future cardiovascular disease including screening, classification and diagnosis, risk factors, risk reduction and follow-up care.

In April of last year, the American College of Obstetricians and Gynecologists (ACOG) issued its Practice Advisory, “Clinical Guidance for the Integration of the Findings of the Chronic Hypertension and Pregnancy (CHAP) Study,”  which updated the organization’s blood pressure reading recommendation to 140/90 from the previously recommended 160/110 “as the threshold for initiation or titration of medical therapy for chronic hypertension in pregnancy.”

An additional ready-reference for further reading is ACOG’s Practice Bulletin Number 22, “Gestational Hypertension and Preeclampsia,” published in June 2020, which provides guidelines for the diagnosis and management of gestational hypertension and preeclampsia.

 For Your Patients

In 2020, the Preeclampsia Foundation released an informative 1-page Patient Information Sheet, downloadable as a PDF at no cost for your patients, which presents the latest data on preeclampsia and cardiovascular disease.  It features patient pointers and tips on screening, steps they can take to reduce their risk, and the importance of talking to you about their pregnancy history.

The contents of this feature are not provided or reviewed by NPWH.