Masked Hypertension in Pediatric Heart Transplant Recipients.

BACKGROUND: Masked hypertension (HTN), especially, isolated nocturnal HTN (INH) has been shown to be a risk factor for cardiovascular disease (CVD) but is not studied well in pediatric heart transplant (PHT) patients. Ambulatory blood pressure monitoring (ABPM) is known to identify patients with HTN but is not used routinely in PHT. METHODS: A single-center, prospective, cross-sectional study of PHT recipients was performed to observe the incidence of masked HTN using 24-h ABPM. The relationship between ABPM parameters and clinical variables was assessed using Spearman correlation coefficient. p value < 0.05 was considered significant. RESULTS: ABPM was performed in 34 patients, mean age 14 ± 5 years, median 5.5 years post-PHT. All patients had normal cardiac function, left ventricular mass index and blood pressure measurements in the clinic. Four patients had known prior HTN and on medications, one of them was uncontrolled. Of the remaining 30 patients, 18 new patients were diagnosed with masked HTN, of which 14 had INH. Diurnal variation was abnormal in 82% (28/34) patients. 24-h diastolic blood pressure (DBP) index correlated with glomerular filtration rate (GFR) (r = - 0.44, p = 0.01). There was no correlation between other ABPM parameters with tacrolimus trough levels. CONCLUSIONS: ABPM identified masked HTN in 60% of patients, with majority being INH. Abnormal circadian BP patterns were present in 82% and an association was found between GFR and DBP parameters. HTN, especially INH, is under-recognized in PHT recipients and ABPM has a role in their long-term care.

COVID-19 infection in pediatric solid organ transplant patients.

BACKGROUND: Adult SOT recipients with COVID-19 have higher mortality rates when compared to general population. There is paucity of data on outcomes in pediatric SOT recipients. METHODS: This is a cross-sectional study investigating the prevalence of COVID-19 infection and outcomes in pediatric SOT (heart, liver, and kidney) recipients. We extracted demographic and clinical characteristics and COVID-19 testing (PCR or [Ab] test) results from medical records. Clinical characteristics were compared between patients who were positive for COVID-19 (PCR or Ab) and those who did not, using Mann-Whitney, Student's t test, or chi-square test. p value <.05 was statistically significant. RESULTS: A total of 108 SOT recipients with a median age of 13.1 (8.4, 17.8) years and median 4.2 (2.7, 7.9) years from transplant were checked for COVID-19 via a PCR or Ab test. A positive PCR was confirmed in 10 patients (9.3%), while 12 patients (11.1%) were positive for COVID-19 Ab. The patients who tested positive in our cohort were 9/50 (18%) heart, 6/68 (8.8%) kidney, and 7/50 (14%) liver transplant recipients. There were no differences in the clinical characteristics between patients with and without COVID-19 infection. All patients were either asymptomatic (50%) or had self-limiting symptoms. No changes were made to the immunosuppressive regimen. Only one patient was hospitalized and none had an oxygen requirement. CONCLUSIONS: In our cohort of pediatric SOT recipients, COVID-19 infection was asymptomatic or mild. This data may aid clinicians in counseling patients and families in this increased-risk population.

Low-Dose Donor Dopamine Is Associated With a Decreased Risk of Right Heart Failure in Pediatric Heart Transplant Recipients.

BACKGROUND: Previous studies in adults have suggested that donor dopamine treatment may improve recipient outcomes in organ transplantation; in this analysis, we aimed to determine if donor dopamine reduces the incidence of postoperative right heart failure (RHF) in pediatric heart transplant recipients. METHODS: Data for recipients aged 18 years or younger transplanted at our institution between January 1, 2000, and June 15, 2011, and their respective donors were obtained. The presence of postoperative RHF was assessed for in all subjects. Donor dopamine dose was stratified into 3 groups: none, low-dose (≤5 µg/kg per minute), and high-dose (>5 µg/kg per minute). Logistic regression was used to assess the relationship between donor dopamine dose and recipient RHF. RESULTS: Of 192 recipients, 34 (18%) experienced postoperative RHF. There was no difference in baseline demographics between recipients with and without RHF. When controlling for pulmonary vascular resistance index, graft ischemic time, and cardiopulmonary bypass time, donor low-dose dopamine was independently associated with a decreased risk of RHF (odds ratio, 0.16; 95% confidence interval, 0.04-0.70; P = 0.02); however high-dose dopamine was neither associated with, nor protective of, RHF (odds ratio, 0.31; 95% confidence interval, 0.06-1.6; P = 0.16). CONCLUSIONS: Despite advances in perioperative care of the recipient, RHF persists as a complication of pediatric heart transplantation. In this study, donor pretreatment with low-dose dopamine is associated with a decreased risk of postoperative RHF in pediatric heart recipients. Further studies into this association may be useful in determining the utility of empiric donor pretreatment with low-dose dopamine.

Elevated pre-transplant pulmonary vascular resistance is not associated with mortality in children without congenital heart disease: a multicenter study.

BACKGROUND: Traditionally, an elevated pulmonary vascular resistance index (PVRI) has been a relative contraindication to pediatric orthotopic heart transplantation. This study examined the risk of elevated pre-transplant PVRI on early (30-day) and intermediate-term mortality in pediatric heart transplant recipients without congenital heart disease (CHD). METHODS: A review of the prospective multicenter Pediatric Heart Transplant Study registry identified all patients without CHD in whom a pre-transplant PVRI was recorded. Of 35 participating centers, 29 reported heart transplants in children with a markedly elevated PVRI (> 5 WU × m(2), corresponding to the highest quartile). Multiphase parametric analysis was performed, adjusting for potential risk factors to assess the association of PVRI with early and intermediate-term mortality. RESULTS: Between 1993 and 2011, 1,909 children without CHD underwent heart transplantation at a median age of 9.7 years (range, 1.6 months-18 years). Of those, 795 (42%) had a recorded or calculable pre-transplant PVRI, and PVRI > 5 WU × m(2) was present in 193 patients (24%). For all recipients, median pre-transplant PVRI was 3.15 WU × m(2) (range, 0.4-23 WU × m(2)); 2.8 WU × m(2) in infants < 1 year, 3.5 WU × m(2) in patients aged 1 to 10 years, and 3.0 WU × m(2) in patients aged > 10 years (p = 0.03). Multivariable hazard analysis controlling for graft ischemic time and pre-transplant ventilation showed no association of elevated PVRI with early mortality (relative risk, 1.2; p = 0.66), nor with intermediate mortality when controlled for year of transplant, age, race, and pre-sensitization (relative risk, 0.7; p = 0.27). CONCLUSIONS: Elevation of PVRI did not affect post-transplant survival in this large, multicenter cohort of pediatric heart transplant recipients without CHD, suggesting that the barrier of elevated PVRI can be successfully overcome in this population.

Left ventricular assist device to avoid heart-lung transplant in an adolescent with dilated cardiomyopathy and severely elevated pulmonary vascular resistance.

Orthotopic heart transplantation remains the definitive treatment of choice for patients with end-stage heart failure; however, elevated PVRI is a reported risk factor for mortality after heart transplant and, when severely elevated, is considered an absolute contraindication. Use of a ventricular assist device has been proposed as one treatment for reducing pulmonary vascular resistance index in potential heart transplant candidates refractory to medical vasodilator therapies. We report on a teenage patient with dilated cardiomyopathy and severely elevated PVRI, unresponsive to pulmonary vasodilator therapy, who underwent left ventricular assist device implantation to safely allow for aggressive pulmonary vasodilator therapy and to decrease PVRI. The resulting dramatic improvement in PVRI in a relatively short period of time allowed for successful heart transplantation, avoiding the need for heart-lung transplant.