A study, involving all six Spanish hospitals with a paediatric heart transplant programme, has analysed all cases between 2006 and 2020 in which a Ventricular Assist Device (VAD) was used in children. Of the 118 cases, 62% received a transplant within the first nine months. In addition, 6% of the patients recovered enough to achieve cardiac organ function without external help. The Vall d'Hebron University Hospital is the only centre in Catalonia that performs heart transplants in paediatric patients, the other centres in Spain are: Hospital Universitario Reina Sofia de Córdoba, Hospital Universitario y Politécnico La Fe de València, Complexo Hospitalario Universitario A Coruña , Hospital General Universitario Gregorio Marañón i Hospital Universitario La Paz de Madrid.

"The study has shown that the percentage of patients transplanted in the first six months of care in Spain is six points higher than the North American registry (PEDIMACS) and 17 points higher than the European study (Paedi-EUROMACS). This finding is probably related to the excellent state organ donation system and the generosity of the Spanish population". Dr Joan Balcells, head of the Paediatric Intensive Care Unit at Vall d'Hebron University Hospital and Principal Investigator of the Clinical Research / Innovation in Pneumonia and Sepsis (CRIPS) group, corresponding author of the study published in the European Journal of Cardio-Thoracic Surgery, explains.

Despite the good transplant rate, the overall survival of the series was lower than that of the North American and European registries. This was due to the different characteristics of the population analysed versus the other studies.  The most notable is their young age (70.4% were younger than five years and 31.4% were younger than one year), while the percentages in the American PEDIMACS were 47.3% and 25.5% and in the Paedi- Euromacs 43.4% and 19.5%. Younger patients are more difficult to assist with current technology and their mortality is higher.

ECMO as a reliable tool to stabilise the critically ill patient before implantation

The study allowed the research team to detect four factors, present at the time of implantation, that affect patients' short- and long-term survival. These are: weight below 5 kilograms, a total bilirubin above 34 micromole per litre, diagnosis of congenital heart disease, and indication of support as a measure to assess whether treatment should be transplant or recovery oriented ("bridge to decision").

The research team also found two other factors that increase long-term mortality. These are: historial of cardiac arrest or implantation in patients with INTERMACS level 1 of heart failure.

The results show the importance of choosing the right time to implant the device. Waiting too long can worsen the patient's condition and decrease his or her chances of long-term survival. On the other hand, if it is installed too early, the benefits may not outweigh the side effects of the procedure, which can include severe bleeding (outside the central nervous system) and stroke.

One measure that can help optimise the options for the most critically ill patients is Extracorporeal Membrane Oxygenation (ECMO). The study has found that the use of this device, prior to implantation, does not increase mortality. This finding validates the option to use ECMO as a tool to stabilise the most critically ill patients first (INTERMACS 1) and then implant the ventricular assist device in better conditions.