Ventricular assist device support in paediatric patients with restrictive cardiomyopathy-clinical outcomes and haemodynamics.

Objectives: Restrictive cardiomyopathy is rare and is generally associated with worse clinical outcomes compared to other cardiomyopathies. Ventricular assist device (VAD) support for these children is seldom applied and often hampered by the surgical difficulties.

Methods: All paediatric (<19 years) patients with a restricted cardiomyopathy supported by a VAD from the EUROMACS database were included and compared to patients with a dilated cardiomyopathy (retrospective database analyses). Participating centres were retrospectively contacted to provide additional detailed echo and Swan Ganz measurements to analyse the effect of VAD support on pulmonary artery pressure and right ventricular function.

Results: Forty-four paediatric VAD-supported patients diagnosed with restricted cardiomyopathy were included, with a median age at implantation of 5.0 years. Twenty-six of the 44 patient with a restricted cardiomyopathy survived to transplantation (59.1%), 16 died (36.4%) and 2 are still on ongoing VAD support (4.5%) after a median duration of support of 95.5 days (interquartile range 33.3-217.8). Transplantation probability after 1 and 2 years of VAD support in patients with a restricted cardiomyopathy were comparable to patients with a dilated cardiomyopathy (52.3% vs 51.4% and 59.5% vs 60.1%, P = 0.868). However, mortality probability was higher in the restricted cardiomyopathy cohort (35.8% vs 17.0% and 35.8% vs 19.0%, P = 0.005). Adverse event rates were high (cerebrovascular accident in 31.8%, pump thrombosis in 29.5%, major bleeding 25.0%, eventual biventricular support in 59.1%). In the atrially cannulated group, cerebrovascular accident and pump thrombosis occurred in twice as much patients (21.1% vs 40.0%, P = 0.595 and 15.8% vs 40.0%, P = 0.464; probably non-significant due to the small numbers). Pulmonary arterial pressures improved after implantation of a VAD, and 6 patients who were initially labelled as ineligible due to pulmonary hypertension could eventually be transplanted.

Conclusions: VAD support in children with a restricted cardiomyopathy is rarely performed. Mortality and adverse event rates are high. On the other hand, survival to cardiac transplantation was 59.1% with all patients surviving the 1st 30 days after cardiac transplantation. Pulmonary arterial pressures improved while on support, potentially making cardiac transplantation a viable option for previously ineligible children.