Assistant professor Texas Children's Hospital Houston, Texas, United States
Abstract:
Background: The relationship between pulmonary hypertension (PH) and outcomes after heart transplant (HT) in pediatric patients is not well characterized. The objective of this study was to evaluate and compare postoperative outcomes in pediatric patients with congenital heart disease (CHD) with and without pre-transplant PH who undergo HT.
Methods: This is a retrospective study that included all pediatric patients with CHD who underwent HT at Texas Children’s Hospital from 2014-2020. Pre-HT PH was defined as pulmonary vasculature resistance (PVR) ≥ 3.0 Woods units (Wu.m2) on hemodynamic catheterization within 12 months of HT or the use of PH-target therapies before HT. The primary outcome was post-operative mortality by 30-, 60- and 90-days post HT. Secondary outcomes included: duration of vasoactive support, inhaled nitric oxide (iNO) use, duration of intubation, postoperative complications (defined as: failed extubation, Extracorporeal Membrane Oxygenator [ECMO] use, Continuous Renal Replacement Therapy [CRRT] use, infections, and arrhythmia), and post-HT ICU and hospital length of stay [LOS].
Results: A total of 71 patients were included, with median age at HT of 4.3 years (IQR 0.7-11.1) and 65% were male. Race/ethnicity distribution were 54% Hispanic, 25% White Non-Hispanic, 20% Black Non-Hispanic, and 1% Asian. Twenty-eight patients had pre-HT diagnosis of PH (24 single ventricle and 4 with bi-ventricular anatomy), of which 22 were on sildenafil monotherapy and 2 on dual-PH therapy. Patients with pre-HT PH (“PH”) had significantly higher PVR (3WU-m2; IQR 1.9-4.5) compared to patients without pre-HT PH (“No-PH”; 1.8 Wu-m2; IQR 1.2-2.2); p< 0.001). PH patients were older when they underwent HT (median PH:118 months vs. No-PH 13 months, p< 0.001), were more likely to have single ventricle anatomy (PH: 86% vs. No-PH: 67%, p=0.006), have less milrinone use pre-HT (PH:32% vs. No-PH:67%, p=0.007) and more ventricular assist device use pre-HT (PH:46% vs. No-PH 12%, p< 0.001). There was no significant difference in postoperative mortality between the two groups by 30-day, 60-day or 90-day post-HT. When comparing postoperative outcomes between the PH and the No-PH groups, the PH group had a longer median duration of epinephrine use and more frequent use of iNO compared to the No-PH group with similar iNO duration. There was no significant difference in post-HT duration of intubation, ICU or hospital LOS, or postoperative complications. PH patients were more frequently discharged on PH target therapy than No-PH subjects; however, the duration use of these medications was not statistically different between groups. See Table 1 for outcomes description.
Conclusion: Pediatric patients with congenital heart disease and pulmonary hypertension that undergo HT do not have a significantly increased risk of post-transplant morbidity or mortality in the post-operative period compared to patients with congenital heart disease without pulmonary hypertension.
