More CV Hospitalizations Later in Life for Mothers of Babies With Heart Defects

Women whose infants are born with congenital heart defects are themselves at higher risk of being hospitalized for a variety of cardiovascular conditions over the ensuing years, according to observational data from Canada.

Multiple factors might explain the link, including genetic predisposition for both mother and baby, differences in behavior, and the added stress of caring for offspring with a serious health problem, lead author Nathalie Auger, MD, MSc (University of Montreal Hospital Research Centre, Quebec, Canada), and colleagues note in their paper published online today in Circulation.

These women merit closer follow-up “in the sense that it provides opportunity for prevention and monitoring,” Auger, a physician-epidemiologist, told TCTMD. “Certainly, if the woman already presents at age 65 with heart disease and she happened to have a child with a heart defect 20 or 30 years ago, that opportunity was missed. But if she’s still young, I think there’s a lot of potential there. . . . You can’t change the fact that her infant had a heart defect but you certainly can change other risk factors like physical activity or smoking.”

Previous research has shown that any sort of major congenital abnormality—not just heart-related—in infants might predispose their mothers to a 26% higher risk of cardiovascular death. This is the first study, Auger said, to look specifically at the impact of heart defects in this way.

Critical and Noncritical Heart Defects Risky

The researchers considered a cohort of 1,084,251 women who delivered babies between 1989 and 2013 in Quebec, looking at a variety of congenital heart defects that fell into two categories: critical and noncritical. Follow-up extended up to 25 years.

Critical defects were those that required attention shortly after delivery to prevent further problems (tetralogy of Fallot, transposition of the great vessels, truncus arteriosus, hypoplastic left heart syndrome, common ventricle, and coarctation of the aorta, among others). Noncritical defects were those for which treatment may be delayed or is not required (endocardial cushion defect, ventricular or atrial septum defect, valve anomaly, heterotaxy, and anomalies of the aorta or pulmonary artery, among others).

Among the mothers, investigators looked for hospitalizations for a diagnosis of a cardiovascular disease or a cardiovascular procedure. Women were more likely to be hospitalized for a cardiovascular condition if they had a baby with a critical defect (3.38 hospitalizations per 1,000 person-years) or a noncritical defect (3.19 per 1,000 person-years) than if their baby was born without a heart problem (2.42 per 1,000 person-years). These hospitalizations also tended to occur earlier than those of women whose children lacked heart defects, and the differences began to emerge not long after pregnancy. Heart failure, MI, and coronary angioplasty accrued more rapidly in the critical-defect group after 10 years of follow-up, while the disparity in valve surgery between women whose babies had critical versus no heart defects became apparent starting at 18 years of follow-up.

You can’t change the fact that her infant had a heart defect but you certainly can change other risk factors like physical activity or smoking. Nathalie Auger

Even when accounting for potential confounders including age, parity, preeclampsia, comorbidity, material deprivation (ie, the inability to afford typical consumer goods and activities), and time period, the association between infant heart defects and CV hospitalization remained apparent for both critical defects (HR 1.43; 95% CI 1.13-1.82) and noncritical (HR 1.24; 95% CI 1.15-1.34), averaging out at a 25% increase in risk with any heart defect. The link was seen for individual outcomes such as MI, pulmonary vascular disease, and pacemaker insertion. Notably, the risk of cardiac transplant was 43.2 times higher (95% CI 6.41-291.70) for women in the critical-defect group than for those whose babies had normal hearts.

There were no significant interactions related to age at first delivery, total number of pregnancies, preeclampsia, comorbidity, or material deprivation.

Mothers’ CV hospitalization also varied based on their infant’s specific type of heart defect, with hypoplastic left heart, tetralogy of Fallot, and heterotaxy carrying the greatest risk after multivariable adjustment.

Based on these findings, the “presence of a heart defect in a woman’s offspring may therefore be a novel risk factor for the development of maternal cardiovascular disease,” the researchers conclude. “More study is needed to determine if women whose infants [have] heart defects could benefit from targeted primary prevention initiatives.”