New Hypertension After Pregnancy in Patients With Heart Disease

Abstract

Background After pregnancy, patients with preexisting heart disease are at high risk for cardiovascular complications. The primary objective was to compare the incidence of new hypertension after pregnancy in patients with and without heart disease. Methods and Results This was a retrospective matched-cohort study comparing the incidence of new hypertension after pregnancy in 832 patients who are pregnant with congenital or acquired heart disease to a comparison group of 1664 patients who are pregnant without heart disease; matching was by demographics and baseline risk for hypertension at the time of the index pregnancy. We also examined whether new hypertension was associated with subsequent death or cardiovascular events. The 20-year cumulative incidence of hypertension was 24% in patients with heart disease, compared with 14% in patients without heart disease (hazard ratio [HR], 1.81 [95% CI, 1.44-2.27]). The median follow-up time at hypertension diagnosis in the heart disease group was 8.1 years (interquartile range, 4.2-11.9 years). The elevated rate of new hypertension was observed not only in patients with ischemic heart disease, but also in those with left-sided valve disease, cardiomyopathy, and congenital heart disease. Pregnancy risk prediction methods can further stratify risk of new hypertension. New hypertension was associated with an increased rate of subsequent death or cardiovascular events (HR, 1.54 [95% CI, 1.05-2.25]). Conclusions Patients with heart disease are at higher risk for developing hypertension in the decades after pregnancy when compared with those without heart disease. New hypertension in this young cohort is associated with adverse cardiovascular events highlighting the importance of systematic and lifelong surveillance.

Keywords: heart disease; hypertension; pregnancy.

Figure 1. Adjusted time‐to‐event curves for incident hypertension.

Adjusted cumulative incidence of hypertension with 95% CIs in the heart disease group and matched comparison group. Numbers at risk were obtained from unadjusted cumulative incidence curves.

Figure 2. CARPREG risk group and adjusted time‐to‐event curves for incident hypertension.

Adjusted cumulative incidence of hypertension and 95% CIs as a function of maternal cardiovascular risk during index pregnancy. Incidence rates are separated into low‐pregnancy‐risk heart disease group vs intermediate‐ to high‐pregnancy‐risk heart disease group, as defined by the CARPREG (Canadian Cardiac Disease in Pregnancy) risk score. Numbers at risk were obtained from unadjusted cumulative incidence curves. Comparison group denotes matched community comparison group.

Figure 3. World Health Organization (WHO) risk group and adjusted time‐to‐event curves for incident hypertension.

Adjusted cumulative incidence of hypertension and 95% CIs as a function of maternal cardiovascular risk during index pregnancy. Incidence rates are separated into low‐pregnancy‐risk heart disease group vs intermediate‐ to high–pregnancy‐risk heart disease group, as defined by the modified WHO risk classification system. Numbers at risk were obtained from unadjusted cumulative incidence curves. Comparison group denotes matched community comparison group. Total patients n=690 for WHO groups, as cardiac lesions in 142 patients could not be classified into a WHO risk group.