Feasibility of cell transplantation with a left ventricular assist device to improve the success rate of left ventricular assist device removal: the first experiment.

Left ventricular assist devices (LVADs) greatly support heart recovery, but recurrent heart failure after LVAD removal limits their use as 'a bridge to recovery'. The combination of LVADs and cell transplantation (CTx) is expected to be effective to improve the success rate of LVAD removal. We investigated the feasibility of combined CTx therapy and LVAD support with a new heterotopic rat heart-lung transplantation model that could simulate LVAD support and LVAD removal. The heart and both lungs of a rat were heterotopically transplanted, and the heart was kept unloaded for two weeks. The heart was then reloaded for two weeks (LVAD group). Syngenic smooth muscle cells were transplanted into the hearts that had been unloaded for a week, and the hearts were kept unloaded for another week and then reloaded (CT-LVAD group). In the unloaded state, CTx could reduce the left ventricle (LV) volume more effectively than LVAD therapy alone (P<0.01) and maintain the LV volume even after the hearts were reloaded (P<0.01). The results suggest that CTx with LVAD support can prevent recurrent LV dilation after LVAD removal and improve the success rate of LVAD removal.