When used as a bridge to heart transplantation in children, a ventricular assist device was associated with significantly higher rates of survival as compared with extracorporeal membrane oxygenation, researchers found.
“Options for mechanical circulatory support as a bridge to transplantation are limited for children,” the Berlin Heart Study Investigators wrote in the article. “The mainstay of support for small children has been extracorporeal membrane oxygenation (ECMO). [However], “the short duration of support afforded by ECMO is often inadequate, considering the current waiting times (a median of 119 days for all infants in 2008). As a result, only 40% to 60% of children requiring support with ECMO survive long enough to undergo heart transplantation.”
Evaluating safety, risk-benefit profile
Thus, Charles D. Fraser, Jr., MD, and colleagues conducted a prospective, single-group trial to evaluate the Excor Pediatric ventricular assist device (Berlin Heart) as a bridge therapy in children on waiting lists for orthotopic heart transplantation. The study included 48 children aged 16 years or younger who were divided into two cohorts based on body-surface area (cohort 1, <0.7 m2; cohort 2, 0.7 m2 to <1.5 m2). Survival among patients receiving mechanical support was compared with two propensity-score–matched historical control groups receiving ECMO, according to the abstract.
Results showed that patients in cohort 1 did not reach the median survival time at 174 days; the median survival in the ECMO group was 13 days (P<.001). Median survival was 144 days for patients in cohort 2 and 10 days for patients in the ECMO group (P<.001).
Serious adverse events in the VAD groups included major bleeding (42% in cohort 1; 50% in cohort 2), infection (63% and 50%, respectively) and stroke (29% and 29%, respectively).
Issues with size, complications
According to the researchers, this study is important because development of pediatric devices has been slow due to greater variation in size among children. The paracorporeal, pneumatically drive, pulsatile-flow device studied is available in a wide range of sizes.
According to Linda J. Addonizio, MD, “the trial thus represents our first baby step toward prospective, evidence-based trials of devices in children.” She said future results from the PUMPKIN program may provide more evidence.
“However, at present, given the rates of neurologic complications in this well-managed trial, we must be cautious in extending the current practice in adults of early implementation of VADs to children, particularly small children,” Addonizio, from the program for pediatric cardiomyopathy, heart failure and transplantation, Columbia University College of Physicians and Surgeons, wrote. “VADs can save lives and successfully provide a bridge to transplantation for children, but they should remain, at present, a last resort in small children.”
For more information:
Addonizio LJ. N Engl J Med. 2012;367:567-556.
Fraser CD. N Engl J Med. 2012; 367:532-554.
Disclosure: This study was supported by Berlin Heart and by a grant from the FDA Office of Orphan Product Development. See the full study for the researchers’ relevant financial disclosures. Dr. Addonizio reports no relevant financial disclosures.