Preeclampsia Increases Heart Attack, Stroke Risk for Up to 20 Years After Pregnancy

Sara Hallum, MSc

The increased risk of acute myocardial infarction (AMI) and ischemic stroke associated with preeclampsia remains elevated for longer than 2 decades, according to new research from the University of Copenhagen.

A registry-based study of more than 1.15 million women with at least 1 pregnancy between 1978 and 2017, results of the study demonstrate women with preeclampsia had a 4-fold increase in risk of AMI and a more than 2-fold increase in risk of ischemic stroke compared to their counterparts without preeclampsia in the first 10 years following first pregnancy, with this increase in risk prevalent more than 20 years later.

“The high risk of cardiovascular disease after pre-eclampsia manifests at young ages and early after delivery,” said lead investigator Sara Hallum, MSc, an epidemiologist and PhD student at the University of Copenhagen, Denmark, in a statement. “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 programmes.”

In a field where mountains of research are published on a weekly basis, cardiovascular care of women remains overlooked and underresearched in the current landscape of cardiology. In a recent episode of the Heart Team, Martha Gulati, MD, offered insight into the recent progress made in reducing the burden of gender disparity in cardiovascular research. Among obstetric complications, the prevalence and associated risk of preeclampsia places it among the most significant risk factors for cardiovascular disease among women at a population level. With this in mind, Hallum and a team of collaborators from the institutions in Denmark designed the current research effort as a registry-based study with the intent of describing the long-term risk of AMI and ischemic stroke among women with preeclampsia and how this risk changes over time.

With this in mind, investigators designed the register-based study to leverage data from women with at least 1 pregnancy from 1978-2017 recorded within Denmark’s Civil Registration System and Medical Birth Register. Excluding those with any circulatory disorders registered prior to first delivery, investigators identified a cohort of 1,157,666 women for inclusion in their study. The median length of follow-up for this cohort was 20.5 (IQR, 10-30.5) years.

Among the overall study cohort 4.0% (n=45,820) had a first pregnancy complicated by preeclampsia. Among women with preeclampsia during first pregnancy, 7.1% (n=3270) had early pre-term preeclampsia, 11.8% (n=5405) had late pre-term preeclampsia, and 81.1% (n=37,145) had term preeclampsia. Investigators noted 58,120 women had 64,357 pregnancies complicated by preeclampsia during the entire duration of the study period.

During 23,503,887 person-years of follow-up, 2.5% (n=8702) of women had an AMI as their first ischemic event and 3.8% (n=13,999) of women experienced an ischemic stroke as their first ischemic events. During the first 20 year following their first pregnancy, 1.2% (n=3089) and 1.8% (n=5119) of women experienced AMI and ischemic stroke, respectively.

Results of the investigators’ analyses indicated up to 2% (95% CI, 1.46-2.82) of women with preeclampsia during their first pregnancy experienced an AMI or stroke within the first 2 decades following delivery compared with up to 1.2% (95% CI, 1.08-1.30) of women without a preeclampsia-complicated pregnancy. Investigators noted results of their analyses demonstrated differences in cumulative incidences in were evident between the study groups as early as 7 years after delivery.

Further analysis suggested preeclampsia was associated with a more than 4-fold risk of AMI (HR, 4.16 [95% CI, 3.16-5.49]) and a more than doubling in risk of ischemic stroke (HR, 2.59 [95% CI, 2.04-3.28]) than women without preeclampsia during the first 10 years after pregnancy, with this relative risk remaining at least doubled up to 20 years later. Investigators called attention to results of subgroup analyses stratified by age, which demonstrated women with preeclampsia aged 30-39 years had a nearly 5-fold increase in risk of AMI (HR, 4.88 [95% CI, 3.55-6.71]) and a more than 2-fold increase in risk of ischemic stroke (HR, 2.56 [95% CI, 1.95-3.36]) compared to their counterparts of the same age without preeclampsia.

“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,” Hallum added. 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.”

This study, “Risk and trajectory of premature ischaemic cardiovascular disease in women with a history of pre-eclampsia: a nationwide register-based study,” was published in the European Journal of Preventive Cardiology.