Oxygenator use in Ventricular Assist Devices from the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) Registry

Objective

To describe the utilization patterns and outcomes of pediatric patients supported with oxygenators during their ventricular assist device (VAD) course.

Design

Multi-center, retrospective cohort study using data from the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) registry.

Setting

Data query from the ACTION registry, which collects clinical data on pediatric patients with end-stage heart disease, reported cases of combined oxygenator-VAD use.

Patients

Sixty-one pediatric patients (27 female) from 21 contributing ACTION centers were supported on oxygenators during their VAD course between 2013-2024. The median age was 272 days (IQR 68-1334), and the median weight was 7.9kg (IQR 4.4-12). The majority had congenital heart disease (CHD), with 66% having single-ventricle pathology.

Interventions

None.

Measurement and Main Results

The study population demonstrated high illness severity at the time of VAD implant, with 97% requiring inotropic support, 79% requiring mechanical ventilation, and 46% on ECMO. The total median duration of VAD support was 45 days (IQR 16-163). Of the 61 patients, 44% achieved transplant or recovery. The mortality rate was high at 52%, and was associated with younger age, smaller size, CHD and pre-implant use of neuromuscular blocking agents. Adverse events included infection (36%), major bleeding (36%), central nervous system injuries (21%), and dialysis (20%). None demonstrated clinically significant association with oxygenator support timing, but mortality was associated with higher adverse events rates, particularly pulmonary hemorrhage, dialysis, and infections (especially mediastinitis).

Conclusion

Pediatric patients requiring oxygenators during VAD therapy exhibit high illness severity and frequent adverse events. Mortality is high and associated with younger age, smaller size, CHD, pre-implant use of neuromuscular blocking agents as well frequency of on-device adverse events, particularly pulmonary hemorrhage, dialysis, and infections. Oxygenator support likely reflects disease severity rather than directly contributing to mortality. Further investigation is needed to optimize patient selection and management strategies.

Research In Context

• Over the past two decades, pediatric VAD utilization has increased. Support from collaborative networks like ACTION has enabled investigation of nuanced strategies, such as temporary oxygenator use, providing a platform to evaluate feasibility, safety, and patient-specific considerations across diverse populations.

• In adult populations, oxygenator use alongside VADs has been employed for respiratory failure, ARDS, RV support, and as a bridge to lung transplant or transition from ECMO. However, these strategies have not been systematically studied in pediatric cohorts until now.

• This study presents the most comprehensive review of pediatric (or adult) oxygenator-VAD support to date, characterizing patient populations, utilization patterns, and associated outcomes. It provides foundational data for guiding future research into management strategies in this high-risk group.

At the Bedside

• Pediatric patients requiring oxygenator support during VAD therapy were typically younger, smaller, and had complex congenital heart disease, particularly single-ventricle physiology. These characteristics were associated with higher mortality and reflect a population with profound critical illness at baseline.

• This cohort experienced high rates of adverse events, including major bleeding, infections, dialysis, and neurologic injury. While oxygenator timing was not independently associated with outcomes, mortality exceeded 50% and was linked to complications such as dialysis, pulmonary hemorrhage, and infections.

• Clinicians should view oxygenator-VAD support as a surrogate marker for extreme illness severity rather than a direct contributor to poor outcome. This study highlights the need for tailored management strategies and informs clinician and family decision-making in this high-risk population.