Increasing Pump Speed During Exercise Training Improves Exercise Capacity in Children with Ventricular Assist Devices

Area of Science:

• Pediatric cardiology
• Cardiovascular engineering
• Rehabilitation medicine

Background:

• Exercise rehabilitation is crucial for children with ventricular assist devices (VADs) awaiting heart transplantation (HT).
• Optimizing exercise capacity during VAD support is essential for improving patient outcomes.
• Current exercise protocols may not fully leverage VAD capabilities.

Purpose of the Study:

• To investigate if increasing VAD pump speed during exercise testing and training enhances exercise capacity in pediatric patients.
• To compare the effects of fixed versus increasing VAD pump speed on exercise parameters.

Main Methods:

• A single-center cohort study comparing historical (fixed VAD pump speed) and prospective (increasing VAD pump speed) groups.
• Serial cardiopulmonary exercise testing (CPET) was used to assess exercise capacity.
• Participants were children with continuous-flow VADs, including those with dilated cardiomyopathy and single ventricle physiology.

Main Results:

• The group with increased VAD pump speed showed a 42% increase in maximal oxygen consumption (VO2) and a 49% increase in maximal work.
• The fixed pump speed group experienced a 3% decrease in maximal VO2 and a 13% increase in maximal work.
• No adverse events were reported in either the fixed or increased pump speed cohorts.

Conclusions:

• Increasing VAD pump speed during exercise training significantly improves aerobic and physical working capacity in pediatric VAD patients.
• This strategy is effective regardless of underlying cardiac physiology (single or biventricular).
• Further research with larger cohorts is recommended to validate these findings for pediatric cardiac rehabilitation.