Neonatal systemic hypertension across the PHIS database: An update

Blood Pressure Outcomes in NICU-Admitted Infants with Neonatal Hypertension: A Pediatric Nephrology Research Consortium Study

OBJECTIVE

To describe the blood pressure outcomes of infants admitted to the neonatal intensive care unit (NICU) with idiopathic (nonsecondary) hypertension (HTN) who were discharged on antihypertensive therapy.

STUDY DESIGN

Retrospective, multicenter study of 14 centers within the Pediatric Nephrology Research Consortium. We included all infants with a diagnosis of idiopathic HTN discharged from the NICU on antihypertensive treatment. The primary outcome was time to discontinuation of antihypertensive therapy, grouped into (≤6 months, >6 months to 1 year, and >1 year). Comparisons between groups were made with χ2 tests, Fisher's exact tests, and ANOVA.

RESULTS

Data from 118 infants (66% male) were included. Calcium channel blockers were the most prescribed class of antihypertensives (56%) in the cohort. The percentages remaining on antihypertensives after NICU discharge were 60% at 6 months, 26% at 1 year, and 7% at 2 years. Antenatal steroid treatment was associated with decreased likelihood of antihypertensive therapy >1 year after discharge.

CONCLUSIONS

This multicenter study reports that most infants admitted to the NICU diagnosed with idiopathic HTN will discontinue antihypertensive treatment by 2 years after NICU discharge. These data provide important insights into the outcome of neonatal HTN, but should be confirmed prospectively.

Common Clinical Scenarios of Systemic Hypertension in the NICU

Hypertension affects ∼1% to 3% of newborns in the NICU. However, the identification and management of hypertension can be challenging because of the lack of data-driven diagnostic criteria and management guidelines. In this review, we summarize the most recent approaches to diagnosis, evaluation, and treatment of hypertension in neonates and infants. We also identify common clinical conditions in neonates in whom hypertension occurs, such as renal vascular and parenchymal disease, bronchopulmonary dysplasia, and cardiac conditions, and address specific considerations for the evaluation and treatment of hypertension in those conditions. Finally, we discuss the importance of ongoing monitoring and long-term follow-up of infants diagnosed with hypertension.

Caring for the hypertensive newborn: a prospective evaluation of risk factors, clinical profile, management, and predictors of outcome of neonatal hypertension

With the advancement of neonatal care and routine blood pressure monitoring, neonatal hypertension (NHT) has been increasingly recognised over the past few decades. NHT is known to cause target organ damage and risk of renal dysfunction later in life. However, diagnosis and management of NHT remain challenging, and there is a lack of evidence on the persistence of hypertension beyond the neonatal period and factors predicting its severity. This study aimed to identify risk factors, clinical profiles, predictors of the severity of hypertension, and short-term outcomes of NHT. A cohort of neonates diagnosed with hypertension requiring pharmacotherapy from September 2019 to July 2021 was prospectively enrolled. Demographic data, risk factors, the severity of hypertension, target organ damage, and follow-up for the persistence of hypertension at 3, 6, and 12 months of age were recorded. Of 1682 neonates admitted during this period, 34 had hypertension requiring pharmacotherapy, with a hospital incidence rate of 2%. Of these, 19 (55.9%) were preterm, 14 (41.2%) very low birth weight, and 15 (44.1%) were small for gestational age. Malignant hypertension was seen in 29 (85%) cases, moderate hypertension in 5 (15%) cases, and target organ damage (heart, brain, liver) was seen in 10 (29.4%) cases. On univariate and multivariate regression, an increasing total number of postnatal risk factors was an independent predictor of the occurrence of hypertensive crisis (OR = 3.5, p = 0.04; 95% CI 1.06-11.42). A significant positive correlation (p = 0.004) was observed between total number of postnatal risk factors and the duration of hospital stay. Renal causes of hypertension were identified significantly earlier (day 14 vs. 23, p = 0.01, 95% CI 2.5-17) and had shorter hospital stay (24 vs 45 days, p = 0.002, 95% CI 834). At 3 months follow-up, 7 (20.6%) babies were still requiring antihypertensive therapy, and 1 (3%) required antihypertensives at 6 and 12 months of age.  Conclusion: NHT is a clinically important but underrecognised entity. Hypertension was seen in preterm, low birth weight neonates and associated with certain maternal and postnatal risk factors, with majority responding to a single drug. Neonates with multiple comorbid illnesses need careful monitoring for hypertension as they are at a higher risk of developing hypertensive crisis. Most NHT cases were normotensive at the time of discharge and did not require pharmacotherapy beyond the neonatal period. What is Known: • Neonatal hypertension (NHT) is an under-recognised entity, and the spectrum of clinical presentation varies from asymptomatic to severe target organ damage. • Hypertension is commonly seen in preterm, low birth weight neonates and associated with certain maternal and postnatal risk factor. What is New: • NHT is mostly transient, but intrauterine growth retardation, use of antenatal steroids, renal dysfunction due to congenital anomalies, drugs, and chronic lung disease may lead to the persistence of hypertension beyond the neonatal period. • Neonates with multiple comorbid illnesses need careful monitoring for hypertension as they are at a higher risk of developing hypertensive crisis. Three-fourths of hypertensive neonates respond to a single antihypertensive drug, and only one-fourth of patients required an additional drug to control hypertension. Most neonates respond to short duration of treatment, and only a few patients require long-term therapy.