35 - Prevalence of Ambulatory/Masked Hypertension in Pediatric Kidney Transplant Recipients using 2022 Guidelines

Childhood hypertension is a significant risk factor for cardiovascular disease. The prevalence of posttransplant ambulatory/masked hypertension in pediatric kidney transplant recipients using the 2022 ambulatory blood pressure monitoring (ABPM) guidelines is unknown.

Objective:

To determine the prevalence, characteristics, and predictors of ambulatory/masked hypertension in pediatric kidney transplant recipients

Design/Methods: We retrospectively identified all pediatric (age < 22 years) kidney transplant recipients who successfully completed 24-hour ABPM for hypertension surveillance per the institutional protocol at the University of Minnesota between 1/2020 and 9/2022. We defined hypertension using the 2022 ABPM guidelines. We compared continuous and categorical variables using the Wilcoxon rank sum and Fisher’s exact tests. We used logistic regression to identify predictors of ambulatory/masked hypertension.

Results: Our cohort included 71 patients with a median posttransplant follow-up time of 5.5 years (IQR: 7.5). Table 1 presents cohort's baseline characteristics. We observed abnormal ABPM (excluding isolated nocturnal blunting) in 23/42 (54.8%) patients already on antihypertensive medications (indicating poor control) and 8/29 (27.6%) patients without an existing diagnosis of hypertension. Among those on antihypertensive medications, 40.5% (n=17) of patients had normal clinic BP but elevated ABPM BP. We observed isolated nocturnal hypertension in 29.6% (n=21) and blunted nocturnal dip in 39.4% (n=28) of all patients. Masked hypertension was seen in 13.8% (n=4) and white coat hypertension in 10.3% (n=3) of patients with no prior hypertension diagnosis (table 2). After adjusting for transplant age, race, donor type, preemptive transplantation, and BMI, the female sex was significantly protective against posttransplant ambulatory/masked hypertension (Adjusted OR: 0.19; 95% CI: 0.05, 0.72; p = 0.01). Left ventricular hypertrophy was more prevalent in children with blunted nocturnal dipping, but the difference did not achieve statistical significance (54.1% vs. 36.8; p=0.36).

Conclusion(s): Using the 2022 ABPM guidelines, ambulatory/masked hypertension is highly prevalent in pediatric kidney transplant recipients. Isolated nocturnal hypertension, blunted nocturnal dipping, and the male sex characterize ambulatory/masked hypertension in this population. Clinic blood pressures may miss poorly controlled hypertension among those on antihypertensive medications. Transplant centers should consider adding 24-hour ABPM to transplant protocols to optimize the diagnosis and management of hypertension.