MILESTONE: More Than 1,200 Children Bridged to Heart Transplantation with Mechanical Circulatory Support.

Pediatric mechanical circulatory support (MCS) has been successfully used to bridge numerous children to transplantation who otherwise would have been unlikely to survive on the waitlist and, in many cases, make them better transplant candidates. The purpose of this study was to analyze what the pediatric heart failure community has achieved over the last 15 years in reaching 1,200 cases of bridging children to heart transplantation. The United Network for Organ Sharing database was used to identify MCS patients ages 0-18 at the time of listing for heart transplantation between 2005 and 2019, divided into three eras: first (2005-2009), second (2010-2014), and third (2015-2019). From 2005 to 2019, 1,289 pediatric cases were identified. More patients were successfully bridged to transplantation with MCS in the third-era (28%) [vs. first-era (16%), second-era (24%), p ≤ 0.004]. The proportion of discharges on ventricular assist device has increased as well from 3% to 22% (p < 0.001). Post-transplant survival was significantly better in the third era (1-year survival: 96%; 3-year survival: 89%) compared to the two previous eras (p = 0.006). On MCS, renal dysfunction, ventilator dependence, inotrope use, and functional status improved from the time of listing to transplantation (p < 0.01). Hepatic dysfunction (p < 0.001), renal dysfunction (p = 0.004), congenital heart disease (p = 0.023), and infant age (p = 0.002) were risk factors for post-transplant mortality. Over the last 15 years, pediatric MCS has become an accepted and increasingly used strategy for bridging children to transplantation. MCS therapy is associated with improved end-organ function at the time of transplantation, perhaps contributing to the increasing post-transplantation survival of patients bridged with MCS.