Improvement of Survival in Low Weight Children on Berlin Heart EXCOR Ventricular Assist Device Support

Objectives: Publications on the pediatric Berlin Heart EXCOR ventricular assist device have revealed that low body weight < 10 kg is a significant risk factor for mortality with children < 5 kg being at highest risk. However, these studies are limited to implantation periods prior to 2011. Since then, progress has been made in optimization of patient selection and management. This study investigated if survival of children weighing < 10 kg supported with the EXCOR assist device improved in recent years and sought to determine risk factors for mortality.

Methods: The Berlin Heart EXCOR prospective registry (n = 1,832) between 2000 and 2017 was retrospectively reviewed to compare the outcomes of different weight cohorts A (< 5 kg) (n = 204), B (5–10 kg) (n = 633), and C (> 10 kg) (n = 995) in different eras (era 1: January 2000–December 2012 [n = 1,089], era 2: January 2013–June 2017 [n = 743]).

Results: Overall survival in groups A and B significantly increased from era 1 to era 2 (group A: 51 vs. 65%, p < 0.001; group B: 74 vs. 78%, p = 0.001) whereas it remained stable in group C (78 vs. 73%). In era 2, the survival of group B was not significantly different than group C. On multivariable analysis of children < 5 kg, congenital heart disease, preoperative extracorporeal life support, and biventricular support were independently associated with increased mortality in era 1 (hazard ratio: 2.04 [95% CI: 1.18–3.53]; 2.44 [1.36–4.37]; and 1.93 [1.11–3.34], respectively) but not in era 2.

Conclusion: Pediatric EXCOR ventricular assist device therapy has improved significantly for children weighing < 10 kg. Withholding of a VAD is not justified on the basis of body weight alone.