Long-Term Cardiovascular Outcomes in Children and Adolescents With Hypertension.

Importance: Hypertension affects 6% of all children, and its prevalence is increasing. Childhood hypertension tracks into adulthood and is associated with subclinical cardiovascular disease; however, there is a lack of evidence linking childhood hypertension to cardiovascular outcomes, which may contribute to underdiagnosis and undertreatment. Objective: To determine the long-term associated risk of major adverse cardiac events (MACE) among children diagnosed with hypertension. Design, Setting, and Participants: This was a population-based, retrospective, matched cohort study conducted from 1996 to 2022. The study included all children (aged 3-18 years) alive in Ontario, Canada, from 1996 to 2021, who were identified using provincial administrative health databases. Children with prior kidney replacement therapy were excluded. Exposure: Incident hypertension diagnosis, identified by validated case definitions using diagnostic and physician billing claims. Each case was matched with 5 controls without hypertension by age, sex, birth weight, maternal gestational hypertension, prior comorbidities (chronic kidney disease, diabetes, cardiovascular surgery), and a propensity score for hypertension. Main Outcomes and Measures: The primary outcome was MACE (a composite of cardiovascular death, stroke, hospitalization for myocardial infarction or unstable angina, or coronary intervention). Time to MACE was evaluated using the Kaplan-Meier method and Cox proportional hazards regression. Results: A total of 25 605 children (median [IQR] age, 15 [11-17] years; 14 743 male [57.6%]) with hypertension were matched to 128 025 controls without hypertension. Baseline covariates were balanced after propensity score matching, and prior comorbidities were uncommon (hypertension vs control cohort: malignancy, 1451 [5.7%] vs 7908 [6.2%]; congenital heart disease, 1089 [4.3%] vs 5408 [4.2%]; diabetes, 482 [1.9%] vs 2410 [1.9%]). During a median (IQR) of 13.6 (7.8-19.5) years of follow-up, incidence of MACE was 4.6 per 1000 person-years in children with hypertension vs 2.2 per 1000 person-years in controls (hazard ratio, 2.1; 95% CI, 1.9-2.2). Children with hypertension were at higher associated risk of stroke, hospitalization for myocardial infarction or unstable angina, coronary intervention, and congestive heart failure, but not cardiovascular death, compared with nonhypertensive controls. Conclusions and Relevance: Children diagnosed with hypertension had a higher associated long-term risk of MACE compared with controls without hypertension. Improved detection, follow-up, and control of pediatric hypertension may reduce the risk of adult cardiovascular disease.