Childhood Hypertension Risk Lingers Years After Heart Defect Surgery

Children who underwent surgery for congenital heart disease (CHD) were at much higher risk of developing hypertension in the long term compared with healthy controls, a retrospective cohort study showed.

The incidence of hypertension was 141.3 per 10,000 person-years after CHD surgery and just 11.1 per 10,000 person-years in matched children without CHD, according to Chirag Parikh, MD, PhD, of Johns Hopkins University in Baltimore, and colleagues.

Ultimately, 12.4% versus 1.1% of these groups developed high blood pressure (BP) over a median 9.8 years of follow-up, the investigators reported in their study online in JAMA Network Open.

“The increased incidence of hypertension is especially significant because hypertension may be a harbinger of adverse cardiovascular outcomes later in adulthood, as seen in earlier research,” Parikh’s group said. “The findings suggest that interventions aimed at reducing the long-term risk of hypertension after cardiac surgery in this population are needed.”

“Our findings provide data to possibly enhance recommendations for BP monitoring and follow-up of children after cardiac surgery,” the authors concluded.

Parikh and colleagues used seven linked administrative databases for their cohort study of individuals in Ontario, Canada. In total, the team identified 3,600 children with surgical repair of CHD, who were matched 1:10 to the general pediatric population without CHD.

Those who had surgical repair had their first surgery at a median 150 days of age. Boys constituted 55.7% of the cohort.

Hypertension was more likely in children who had surgery before age 150 days, those who had more complex surgery (e.g., repair for hypoplastic left heart syndrome, double-outlet right ventricle, coarctation of the aorta, atresia of the pulmonary artery), and those who had dialysis during their index cardiac surgery hospitalization.

“Age at surgery may be a surrogate for the severity of the congenital heart defect because infants who urgently require surgical repair for severe disease cannot delay surgery to an older age. In addition, hypertension is common in specific types of CHD that are more likely to be repaired at an early age, such as coarctation of the aorta and hypoplastic left heart syndrome,” Parikh’s group explained.

“Also, the immature kidney function and limited physiologic reserve of neonates may contribute to their long-term risk of hypertension after cardiac surgery. However, the cumulative risk of hypertension is high even among those who underwent their index surgery at age 150 days or older,” the researchers wrote.

They acknowledged that the study relied on hypertension identified from administrative codes, rather than individual BP measurements or prescription of antihypertensive medications.

In addition, the analysis was subject to potential ascertainment bias, the team noted. Children undergoing cardiac surgery have more healthcare encounters where BP would be checked, whereas most healthy children do not undergo BP monitoring.

Indeed, the 1.1% observed risk of hypertension for controls was just 1.1% in the study, compared with an estimated prevalence of 3.5% in the general pediatric population.

The investigators suggested that future research use single clinic measurements of BP as well as ambulatory BP monitoring and neurohormonal assessments to better characterize the burden and mechanisms of hypertension in children with prior surgery for CHD.

Clinical trials are also needed to test interventions for hypertension and determine optimal BP targets, the team added.