Dallas, TX - The vast majority of children waiting for a donor heart can be successfully bridged to transplantation with a ventricular assist device (VAD) as needed, with better results in patients with cardiomyopathy as compared with congenital disease, according to an analysis of a US database [1].

"Improved outcomes in the most recent era may be influenced by the centers' increasing experience with the surgical techniques, timing, and postoperative care; the use of more long-term devices over time; and refinements in patient selection," write Dr Elizabeth D Blume (Children's Hospital Boston, MA) and associates in the May 16, 2006 issue of Circulation. "In fact, these refinements appear to have resulted in improved outcomes over time despite the increasing use of VADs in smaller and more complex patients."

This is clearly a challenging environment in which to provide mechanical circulatory support, and it is remarkable in this context that the results in this series were as good as they were.

The Pediatric Heart Transplant Study (PHTS) database, repository for data from 23 centers on most pediatric heart transplantations performed in North America, listed 99 cases of VAD bridging among the 2276 patients wait-listed from 1993 through 2003. Analysis of the VAD group and their comparison with patients who were not VAD-supported showed that:

• Median age at pump implantation was 13.3 years (range, two days to nearly 18 years). The VADs were used for an average 57 days, but again, the time ranged widely from one to 465 days. The indication for transplantation was cardiomyopathy in 78% of patients and congenital disease in the remainder.
• Although 77% of VAD recipients survived to transplantation over the entire decade, 86% of them were successfully bridged from 2000 through 2003.
• Survival both after the start of wait-listing and for five years after transplant was statistically similar for patients who were and were not bridged with a VAD.
• In multivariate analysis, VAD implantation prior to 2000, female sex, and congenital heart disease emerged as significant mortality risk factors. Stroke accounted for about 65% of deaths during VAD support.
• Major adverse VAD-related events included reoperation for bleeding, infection, stroke, and hemolysis. Strokes were more common in patients with devices intended for short-term use, and infection rates were higher with long-term VADs.

One of the analysis' "most striking aspects" is that over a decade at 23 centers, only 4% of pediatric heart transplantations involved VAD bridging, observe Drs David Rosenthal and Daniel Bernstein (Packard Children's Hospital at Stanford University, CA) in an accompanying editorial [2]. They also note the limited experience with the procedure at individual centers: almost half of them implanted only one or two VADs during the entire period. "This is clearly a challenging environment in which to provide mechanical circulatory support, and it is remarkable in this context that the results in this series were as good as they were."