BackgroundThis study assessed the possibility of a bridge to recovery using the Berlin Heart EXCOR and the histologic characteristics of pediatric patients with dilated cardiomyopathy accompanied by a left ventricular noncompaction phenotype. MethodsOf the 17 pediatric patients with dilated cardiomyopathy who underwent Berlin Heart EXCOR implantation between 2013 and 2020, 6 were diagnosed with left ventricular noncompaction association. The patients were classified into 2 groups: the dilated cardiomyopathy group and dilated cardiomyopathy with the left ventricular noncompaction phenotype group. The histologic characteristics of the left ventricular myocardium and left ventricular function after Berlin Heart EXCOR implantation were compared. ResultsCardiac recovery was not observed in the dilated cardiomyopathy with left ventricular noncompaction group. In contrast, 6 patients (55%) in the dilated cardiomyopathy group achieved cardiac recovery, and the Berlin Heart EXCOR was explanted. The degree of myocardial fibrosis was significantly higher in the dilated cardiomyopathy with the left ventricular noncompaction phenotype group than in the dilated cardiomyopathy group (P < .05). The final follow-up left ventricular ejection fraction and end-diastolic diameter during Berlin Heart EXCOR support improved significantly compared with the preimplantation variables in the dilated cardiomyopathy group (both P < .001); the dilated cardiomyopathy with left ventricular noncompaction phenotype group showed no improvements (P = .84 and P = .37, respectively). ConclusionsThe left ventricular noncompaction phenotype associated with dilated cardiomyopathy may adversely affect the rate of cardiac recovery with Berlin Heart EXCOR.