Frontal cerebral blood flow is impaired in patients with heart transplantation

Patients with cardiovascular disease have cognitive function disturbances that are still evident after heart transplantation (HT). The aim of this study was to evaluate cerebral function in transplant patients and to assess whether cyclosporine therapy was responsible for cerebral abnormalities 1 year after transplantation. Six HT patients, eight liver transplant (LT) patients, and ten age-matched healthy controls underwent regional cerebral blood flow (rCBF) assessment by the (99m)Tc-hexamethyl-propylene-amineoxime ((99m)Tc-HM-PAO) single-photon emission computed tomography (SPECT) technique. The rCBF was correlated with cyclosporine blood levels. rCBF in HT and LT patients was similar to that of controls in all regions assayed, except for the frontal inferior region of HT patients, where it was significantly lower than in controls. No correlations between rCBF and cyclosporine blood levels were found in either HT or LT patients. In conclusion, the cerebral abnormalities seen in patients after HT but not after LT may be due to long-standing cerebral hypoperfusion resulting from severe heart disease, whereas cyclosporine does not account for such functional alterations.