The Use of Ambulatory Blood Pressure Monitoring in Pediatric Heart Transplant Recipients

Ambulatory blood pressure monitoring (ABPM) is the gold-standard non-invasive test for diagnosing arterial hypertension; however, it remains understudied in pediatric heart transplant recipients (HTRs). We evaluated the role of ABPM in diagnosing and managing hypertension.

We conducted a single-center retrospective evaluation of pediatric HTRs transplanted between 2010 and 2023 (inclusive) with ≥ 1 post-transplant ABPM. Clinic blood pressures (CBPs) temporally linked to each ABPM were used to categorize patients into blood pressure phenotypes: normotensive (including well-controlled hypertension, if on anti-hypertensive therapy), sustained, white coat (WCH), and masked hypertension (MH). Demographic, clinical, and echocardiographic characteristics were compared across hypertensive phenotypes, with longitudinal changes evaluated using serial ABPMs.

Data were available for 33 pediatric HTRs (61% female [20/33], median age at first ABPM 7.3 [5.3-10.4] years, 0.7 [0.2-2.6] years post-transplant). At the initial ABPM, 82% (27/33) were normotensive and 18% (6/33) were hypertensive, with 79% (26/33) on ≥ 1 antihypertensive medication. Of those with hypertensive CBPs, 60% (6/10) had a normal ABPM indicating WCH. At subsequent ABPM, 48% (10/21) normotensive patients remained normotensive, while 43% (9/21) developed hypertension. Among the 6 patients with WCH, 5 (83%) developed subsequent hypertension by ABPM. Median left ventricular mass was higher in hypertensive patients (160.9 g, 64.3-172.3 g) compared with WCH (54.4 g, 36.9-100.7 g) and normotensive patients (66.9 g, 45.4-94.3 g) (p = 0.032).

ABPM provides important hypertension insights for pediatric HTRs, especially with abnormal CBPs. Progression from WCH to manifest hypertension was common. ABPM should therefore be utilized prior to implementing or modifying anti-hypertensive therapy.