17 - Ambulatory Blood Pressure Monitoring in Children Post-Hematopoietic Stem Cell Transplantation

Poster Number: 17
Publication Number: 17.322

warinpapha Homhuan, Ramathibodi hospital, Mahidol university, Bangkok, Krung Thep, Thailand; Kwanchai Pirojsakul, Ramathibodi Hospital Mahidol University, Bangkok, Nonthaburi, Thailand; Samart Pakakasama, Mahidol University, Ratchathewee, Krung Thep, Thailand; Marin Satawiriya, Pediatric Cardiology, Department of Pediatrics, Ramathibodi Hospital Mahidol University, Prawet, Krung Thep, Thailand

Background: Approximately 80% of patients who survive the first 2 years following hematopoietic stem cell transplantation (HSCT) become long-term survivors but still habor long-term complications including hypertension (HT). Ambulatory blood pressure monitoring (ABPM) is a procedure of blood pressure (BP) measurement for 24-hours and can detect HT outside the office. Previous studies showed that 10-15% of children post-HSCT have HT by office BP measurement but few studies used ABPM. 

Objective: This study aimed to use ABPM to find the prevalence of HT and its associated factors.

Design/Methods: Patients aged ≥6 years who survived ≥2 years after HSCT were enrolled. Clinical data and laboratory parameters were collected. ABPM was performed to obtain BP for 24 hours. Office HT was defined as BP ≥ P95th for gender, age and height (aged < 13 years); or 130/80 mmHg (aged ≥ 13 years). ABPM HT was defined as average BP ≥ P95th for gender and height (aged < 13 years); or ≥ 125/75, 130/80, 110/65 mmHg (aged ≥ 13 years) for 24-hour, awake or sleep periods, respectively. Masked HTwas defined as ABPM HT but normal office BP, while sustained HT was defined as HT by both ABPM and office BP. BP indices were calculated as follows: BP value divided by hypertension cut-off value for each patient. Factors associated with HT were analyzed by logistic regression analysis.


Results:

Among 141 eligible patients, 34 refused to participate and 10 had insufficient ABPM data. Therefore, 97 patients were included. Underlying diseases were thalassemia (48.5%), malignancy (39.2%) and others (12.4%). Sixteen patients (16.5%) with ABPM HT were detected (2 sustained HT and 14 masked HT). The ABPM HT group had a higher age (19.2 vs. 14 years, p=0.012), a higher proportion of male gender (87.5% vs. 56.8%, p=0.02), a higher office SBP index (0.93 vs. 0.85, p< 0.01) and a higher office DBP index (0.96 vs. 0.83, p< 0.01) than those of the normal ABPM group. Male gender, office SBP index and office DBP index were significantly associated with ABPM HT. Multivariate analysis showed that only office DBP index was associated with ABPM HT.

Conclusion(s): HT in children post-HSCT was not uncommon and most could not be detected with office BP measurement. Therefore, ABPM may be useful to detect HT outside the office setting. If ABPM is not available, pediatricians may choose to refer children post-HSCT who have a high office DBP index.