Women who experience hypertensive disorders during pregnancy are at an increased risk for cardiovascular disorders later in life, according to a study published in Circulation.
The aim of the population-based cohort study researchers was to assess the association between preeclampsia, preterm preeclampsia, and hypertensive disorders of pregnancy and the risk for a cardiovascular disorder diagnosis after pregnancy. Data were extracted from the Cardiovascular Research using the Linked Bespoke Studies and Electronic Health Records (CALIBER), the Clinical Practice Research Datalink, the Hospital Episodes Statistics, and the Office for National Statistics cause-specific mortality records. Using these records, pregnancies were categorized as either non-preeclamptic or preeclamptic, and both term preeclampsia and preterm preeclampsia were analyzed in subgroups.
Ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, stroke not otherwise specified, myocardial infarction, stable angina, unstable angina, coronary heart disease not otherwise specified, peripheral arterial disease, abdominal aortic aneurysm, atrial fibrillation, and heart failure were the 12 cardiovascular disorders of interest postpregnancy. Baseline measurements were recorded around 16 weeks of pregnancy, and the study followed patients for up to 20 years, with a median follow up of 9.25 years.
This study included 1,303,365 women who had 1,899,150 pregnancies. Of these women, 2.42% had a preeclamptic pregnancy, with 76.64% occurring in the first pregnancy, 17.43% occurring in the second pregnancy, and 5.93% occurring in the third or subsequent pregnancies.
Of the first-incident cardiovascular events, 65.12% occurred in women under the age of 40 years old. Women who experienced a preeclamptic pregnancy were more likely to deliver preterm to a lower mean birth weight infant (P <2.2×10⁻¹⁶), more likely to be nulliparous, diabetic, hypertensive, and overweight or obese, and were less likely to be smokers (P <.001, all).
Postpregnancy cardiovascular disorders occurred in 2.77% of the preeclamptic cohort and 1.40% of the non-preeclamptic cohort, with the women in the preeclamptic cohort at a higher risk for all cardiovascular disorders of interest except for intracerebral hemorrhage and abdominal aortic aneurysm. One preeclamptic event increased the risk for a cardiovascular disorder with a hazard ratio [HR] of 1.69 (95% CI, 1.57-1.81), and women with preterm preeclampsia had an even higher risk for chronic hypertension with an HR of 5.65 (95% CI, 5.10-6.26). When analyzing specific cardiovascular events, preeclampsia increased the risk for all stroke with an adjusted HR of 1.68 (95% CI, 1.30-2.18); cardiac atherosclerotic with an adjusted HR of 1.45 (95% CI, 1.32-1.59); other cardiovascular disease with an adjusted HR of 1.43 (95% CI, 1.15-1.76); all peripheral disease with an adjusted HR of 1.60 (95% CI, 1.12-2.29); and for all cardiovascular events combined with an adjusted HR of 1.45 (95% CI, 1.34-1.57).
When assessing the time span between a preeclamptic pregnancy and a cardiovascular disorder, there was an increase of cumulative incidence in year 1 which doubled by year 2 when compared with non-preeclamptic pregnancies.
Limitations of this study include the use of databases to collect all of the data, the possibility for selection bias to occur for patients entered into the databases, and the lack of potential confounding variables not entered in the databases.
”Hypertensive disorders of pregnancy should be considered as a natural screening tool for cardiovascular events, enabling cardiovascular risk prevention through national initiatives,” the study authors concluded.
Leon LJ, McCarthy FP, Direk K, et al. Preeclampsia and cardiovascular disease in a large UK pregnancy cohort of linked electronic health records: a CALIBER study [published online September 23, 2019]. Circulation. doi:10.1161/CIRCULATIONAHA.118.038080