Bridge to recovery with Berlin Heart EXCOR in children <10 kg with dilated cardiomyopathy: a histological analysis.

OBJECTIVES

This study aimed to identify the histological characteristics associated with bridge to recovery using Berlin Heart EXCOR® (BHE) in paediatric patients <10 kg with dilated cardiomyopathy.

METHODS

Of the 10 consecutive patients <10 kg with dilated cardiomyopathy who underwent BHE implantation between 2013 and 2018, 4 patients showed improvement in left ventricular (LV) function, resulting in successful BHE explantation (recovery group). The remaining 6 patients showed persistent LV dysfunction and underwent heart transplantation (non-recovery group). The following variables were compared between the 2 groups: (i) histological findings in LV myocardium obtained at BHE implantation and (ii) LV function after BHE implantation assessed with echocardiography and cardiac catheterization.

RESULTS

The degree of myocardial fibrosis was significantly lower, and the capillary vascular density was significantly higher in the recovery group than in the non-recovery group [16% (standard deviation 5.9%) vs 28% (5.9%), P = 0.021, and 65 (11) vs 43 (18) units/high-power field, P = 0.037, respectively]. The changes during 3 months after BHE implantation in LV diastolic dimension (z-score) and ejection fraction were significantly greater in the recovery group than in the non-recovery group [-9.6 (3.5) vs -3.6 (4.5), P = 0.045, and 36% (13%) vs 13% (13%), P = 0.032, respectively].

CONCLUSIONS

In paediatric patients <10 kg with dilated cardiomyopathy, bridge to recovery with BHE implantation was achieved in patients with less injured LV myocardial histology at BHE implantation.