Hypertension During Pregnancy Linked to Increased Risk of Premature All-Cause and CVD Mortality

Hypertensive disorders of pregnancy (HDP), either gestational hypertension or pre-eclampsia, are associated with an increased risk of premature mortality, especially from cardiovascular disease (CVD) even in the absence of chronic hypertension, according to a study in the Journal of the American College of Cardiology.

Researchers sought to determine whether HDP were associated with premature mortality. They followed 88,395 parous female nurses participating in the Nurses’ Health Study II between 1989 and 2017. The women had a mean age at first birth of 26.7 ± 4.7 years and a mean pre-pregnancy body mass index of 21.0 ± 3.0 kg/m². A total of 12,405 women (14.0%) had hypertensive disorder in at least 1 pregnancy.

After 2,355,049 person-years of follow-up, the study authors found that 2387 women died before age 70 years, including 1141 (48%) cancer deaths and 212 (9%) CVD deaths. Analysis with age-adjusted Cox proportional models demonstrated that gestational hypertension or pre-eclampsia was associated with a hazard ratio (HR) of 1.42 (95% CI, 1.28 to 1.58) for premature death during the follow-up.

These associations remained statistically significant but were slightly attenuated after additional adjustment for potential confounding factors (HR, 1.32; 95% CI, 1.19 to 1.47) and time-varying (postpregnancy) dietary, lifestyle, and reproductive characteristics (HR, 1.31; 95% CI, 1.18 to 1.46).

Analysis of specific causes of death showed that the occurrence of HDP was related to a higher risk of premature CVD mortality (HR, 2.26; 95% CI, 1.67 to 3.07) but was unrelated to premature cancer mortality (HR, 0.97; 95% CI, 0.82 to 1.150).

When subsequent chronic hypertension was taken into account, the study authors found an increased risk of all-cause premature mortality in relation to HDP only (HR, 1.20; 95% CI, 1.02 to 1.40), chronic hypertension only (HR, 1.67; 95% CI, 1.50 to 1.84), and both HDP and subsequent chronic hypertension (HR, 2.02; 95% CI, 1.75 to 2.33). A similar pattern was observed for mortality from CVD: (HR, 1.71; 95% CI, 1.01-2.92); (HR, 3.23; 95% CI, 2.26-4.63); and (HR, 6.35; 95% CI, 4.22-9.54), respectively.

Investigators reported it noteworthy that the increased risk of premature mortality appeared to be driven by the small number of women who had hypertensive disorders in 2 or more pregnancies as well as by women who simultaneously reported HDP and low birth weight.

Among several study limitations, the researchers noted that the diagnoses of HDP and chronic hypertension were self-reported. Also, because the study population was mainly professional, non-Hispanic white women (about 92%), the findings may not be generalizable to ethnic and racial minority groups and across all socioeconomic levels.

“Our results suggest that HDP, either gestational hypertension or pre-eclampsia, were associated with a greater risk of premature mortality, especially CVD-related deaths, even in the absence of chronic hypertension,” the researchers commented. “[These findings] highlight the need for clinicians to screen for a history of HDP when evaluating CVD morbidity and mortality risk of their patients.”

Reference

Wang Y-X, Arvizu M, Rich-Edwards JW, et al. Hypertensive disorders of pregnancy and subsequent risk of premature mortality. J Am Coll Cardiol. 2021;77(10):1302-1312. doi.org/10.1016/j.jacc.2021.01.018.