How have pediatric VADs advanced and what’s next?

Pediatric ventricular assist devices (VADs) have been associated with better survival to heart transplantation in recent years but infants and those with congenital heart disease (CHD) continue to have worse outcomes, researchers reported in the Journal of the American College of Cardiology.

Lead author Anne I. Dipchand, MD, and colleagues studied 7,135 children who were listed for heart transplantation between 1993 and 2015. More than 5,000 of them eventually received transplants and 995 (19.3 percent) were supported by a VAD.

Among the researchers’ findings:

  • 79 percent of patients who received a VAD as their first support device survived to heart transplantation and 14 percent died. For children who transitioned from extracorporeal membrane oxygenation (ECMO) to a VAD, 69 percent survived to transplantation and 24 percent died.
  • Patients with cardiomyopathy had a 9 percent waitlist mortality rate, compared to 26 percent for CHD.
  • Post-transplantation survival among patients with VADs versus no support was similar at two years (75 versus 80 percent) and 20 years (55 versus 54 percent).
  • The rate of waitlist mortality dropped from 24 percent in 1993-2004 to 16 percent in 2010-2015.
  • Two-year survival post-VAD implant was 78 percent for patients age 10 or older, but just 53 percent for infants. But when heart transplants were completed, survival from that point was similar between groups.
  • A third of patients with a temporary VAD died while awaiting transplantation, versus 14 percent of those on the waitlist who were implanted with a durable device.

 “For one-quarter of a century, major advances have occurred in mechanical support technology for children, thereby expanding the capability to bridge to heart transplantation without compromising post-heart transplantation outcomes,” Dipchand and coauthors wrote. “Significant challenges remain, especially for neonates and patients with CHD, but ongoing innovation portends improved methods of support during the next decade.”

The authors noted VADs are now being used before heart transplantation in about one-third of eligible patients. As their use has increased, outcomes have generally improved.

“Durable VAD post-transplantation survival has improved over time, and five-year post-transplantation survival from durable VAD was less than 80 percent in the most recent era,” they noted. “Post-implantation survival was better for older children (less than 10 years) compared with infants, but importantly, post-transplantation survival was the same. Hence VAD development for this key age group would make a tremendous impact on overall outcomes.”

In a related editorial, two physicians said the study is a “brilliant summary” of the pediatric VAD experience over the last 25 years. They believe the development of durable, fully implantable continuous-flow VADs for smaller patients (below 22 pounds) and those with CHD is needed to extend the improved outcomes to a broader population.

“Although heavily encumbered by the wide variety of devices implanted across several eras of study that witnessed transformative evolution in VAD technology, this paper serves not only as an important reference that reflects actual practice pattern and therapeutic strategies as they pertain to VAD use in children but also as a document to highlight the ongoing areas of controversy and consistently poor outcomes that warrant our future clinical focus,” wrote Sean P. Pinney, MD, and Jonathan M. Chen, MD.