Pregnancy-Induced Hypertensive Disorder Associated With Increased Risk for HF

Patients without a history of cardiovascular disease (CVD) and who have pregnancy-induced hypertensive disorder have an increased short- and long-term risk for nonischemic and ischemic heart failure (HF), investigators reported in JACC: Heart Failure.

The population-based, observational, matched cohort study evaluated the association between pregnancy complicated by pregnancy-induced hypertensive disorders in primiparous women and risk for ischemic and nonischemic HF.

The Medical Birth Register in Sweden was used to identify primiparous women who gave birth from 1988 through 2019. The participants with hypertensive disorder of pregnancy were individually matched with up to 5 comparator patients according to maternal age at delivery and year of delivery. The matched comparators did not have hypertensive disorder during the index pregnancy.

The follow-up ended at the outcome, death from cause other than HF, first migration from Sweden, or the study end date of December 31, 2020, whichever came first.

A total of 79,334 women with pregnancy-induced hypertension were matched with 396,531 women with a normotensive pregnancy. The median follow-up was 13.2 (IQR, 6.1-22.0) years (exposed to hypertension, 13.2 [IQR, 6.2-22.0] years; unexposed, 13.1 [IQR, 6.1-22.0] years).

The women with pregnancy-induced hypertensive disorder had an incidence rate of overall HF of 3.3 per 10,000 person-years, compared with 1.8 per 10,000 person-years in the matched normotensive comparator patients (crude hazard ratio [cHR], 1.81 [95% CI, 1.61-2.04]; adjusted HR [aHR], 1.70 [95% CI, 1.51-1.91]).

Incident nonischemic HF occurred in 290 (0.5%; 2.6 per 10,000 person-years) women with pregnancy-induced hypertensive disorder vs 869 (0.2%; 1.5 per 10,000 person-years) in the comparator group during follow-up, for an increased rate of about 60% of nonischemic HF after pregnancy-induced hypertensive disorder (cHR, 1.67 [95% CI, 1.47-1.91]; aHR, 1.60 [95% CI, 1.40-1.83]). In addition, 88 (0.1%; 0.8 per 10,000 person-years) women with pregnancy-induced hypertensive disorder and 168 (0.04%; 0.3 per 10,000 person-years) of matched normotensive women had ischemic HF (cHR, 2.59 [95% CI, 2.00-3.36]; aHR, 2.08 [95% CI, 1.44-3.00]).

Preterm delivery occurring prior to gestational week 34 was associated with a 2.5-fold increased rate of any HF (cHR, 2.46 [95% CI, 1.82-3.32]), a 2.3-fold increased rate of nonischemic HF (cHR, 2.33 [95% CI, 1.65-3.31]), and a 3.6-fold increased rate of ischemic HF (cHR, 3.64 [95% CI, 1.97-6.74]).

The incidence rates were greatest within 6 years after a hypertensive index pregnancy (any HF: cHR, 2.09 [95% CI, 1.52-2.89]; nonischemic HF: cHR, 1.86 [95% CI, 1.32-2.61]; and ischemic HF: cHR: 6.52 [95% CI, 2.00-12.34]). The rates decreased slightly afterward but were still significantly increased during all time periods.

The researchers noted that women with a history of pregnancy-induced hypertensive disorder may have an increased prevalence of subclinical ischemic heart disease, including coronary artery calcification, which could have resulted in an underestimation of the risk for ischemic HF and overestimation of the risk for nonischemic HF. Also, residual confounding is possible, and the study had limited power in some of the stratified and adjusted analyses. Furthermore, the findings are based on demographic characteristics of the Swedish population and health care settings.

“Primiparous women without a history of CVD and pregnancy-induced hypertensive disorder are at increased short-term and long-term risk of nonischemic and ischemic heart failure,” the study authors wrote.