Clinical Assistant Professor Stanford University Palo Alto, California, United States
Abstract:
Introduction: Pediatric pre-capillary pulmonary hypertension (PH) can develop in response to left atrial hypertension, and decompression following ventricular assist device (VAD) implantation may not be sufficient to decrease pulmonary vascular resistance (PVR) to acceptable levels to consider heart transplantation. Prostacyclins have been used in adult patients with success, but pediatric data on safety and efficacy in this population is limited. Our center uses prostacyclin therapy as adjunctive therapy in patients with persistent PH despite adequate left atrial decompression. We sought to describe our experience to demonstrate its safety and to present our current protocol for perioperative use.
Methods: We retrospectively reviewed our use of prostacyclin therapy in pediatric VAD recipients from 2016 to 2021. 17 patients met inclusion criteria of < 21 years of age at time of VAD implant and prostacyclin usage at any dose. All VAD types, indications, and anatomies (single vs two ventricle) were included. Demographic, biometric, end organ function, duration of therapy, and hemodynamic data were collected.
Results: Of the 17 patients, 12 survived to transplant and 1 patient is still alive with VAD in situ. All patients survived post-transplant. 10 patients received treprostinil and 8 received epoprostenol during their course, 7 of those received both therapies at various points (Figure 1). Most patients received concurrent therapy with sildenafil or tadalafil. With prostacyclin therapy, there were no bleeding complications or worsening of end organ function. Only one patient discontinued treatment due to platelet dysfunction detected on thromboelastography, but no clinical bleeding was noted. We found a statistically significant reduction in vasoactive inotropic scores (VIS) in the first 24 hours after initiation of prostacyclin (Figure 2). We did not have sufficient hemodynamic data in this small sample to demonstrate efficacy in dropping PVR as many patients were deemed too ill prior to VAD implantation to undergo hemodynamic catheterization. However, the proportion of patients surviving to transplant in this high-risk cohort is favorable.
Conclusions: In our small sample, Prostacyclins were safe to use in the peri-VAD period. Bleeding complications were not present in our cohort although subtle platelet defects were detected in one patient for which prostacyclin was discontinued. Prostacyclin therapy combined with VAD implantation could be considered for patients where elevated pulmonary vascular resistance would otherwise preclude transplantation. We have also included our current protocol for use of prostacyclins in the OR at the time of VAD implantation (Figure 3).
