小児におけるベルリンハートサポートの経験：デバイス除去に焦点を当てて

The Berlin Heart EXCOR is the only durable ventricular assist device available for infants and small children. A subset of patients supported by the Berlin Heart EXCOR device experience cardiac recovery. This study aimed to evaluate the outcomes of Berlin Heart EXCOR support at our center and identify the factors associated with successful device explantation.

This retrospective observational study included all consecutive patients who underwent Berlin Heart EXCOR implantation at the Royal Children's Hospital from 2009 to 2024.

A total of 72 patients received Berlin Heart EXCOR support during the study period. The median age at implantation was 1.0 year (interquartile range, 0.44-2.92), median body surface area was 0.43 m² (interquartile range, 0.30-0.56), and median support duration was 127 days (interquartile range, 59-219). Heart transplantation was performed in 47 patients (65.3%), and 10 patients (13.9%) achieved device explantation without transplantation-4 with dilated cardiomyopathy and 6 with myocarditis. Fourteen patients (19.4%) died on support, and 1 patient remained supported at analysis. There were no significant differences in age, body surface area at implantation, or duration of support between those who recovered and those who died or underwent transplantation. Of 30 patients aged less than 2 years with body surface area between 0.35 and 0.55 m², 9 achieved recovery. In contrast, none of the 23 patients with body surface area less than 0.35 m² and only 1 of 18 patients with body surface area more than 0.55 m² successfully underwent explantation. In multivariable Cox regression, myocarditis was significantly associated with successful explantation (hazard ratio, 11.6, 95% CI, 0.987-135.1; P = .05). Because of the low number of recovery events and near-complete separation by body surface area category, Firth's penalized Cox regression was applied. Within this model, body surface area between 0.35 and 0.55 m² was strongly associated with recovery (hazard ratio, 27.4, 95% CI, 3.46-3539.5; P = .0003).

This study demonstrates that a strategy focused on evaluation of myocardial recovery may increase the rate of device removal. The majority of successful device removals occurred in children younger than 2 years of age with a body surface area of 0.35 to 0.55 m². Patients with myocarditis are more likely to have a successful device removal. We believe that every patient must be evaluated for myocardial recovery and device removal before committing the patient to heart transplantation.