Effects of cyclosporine on the transplanted human heart.

The possible short-term effects of cyclosporine on the heart were studied in 42 endomyocardial biopsies taken at the time of high levels of cyclosporine in the blood, in 20 biopsies at low blood cyclosporine levels, and in 44 biopsies taken from patients on a conventional (before cyclosporine) regimen of azathioprine and steroids after heart transplantation. More long-term effects were studied in postmortem heart sections from 11 liver transplant patients, six of whom had received cyclosporine immunosuppression therapy. The weight of transplanted hearts at necropsy and at retransplantation were analyzed, and in each of the groups of rejectors and nonrejectors, the hearts treated with cyclosporine were significantly heavier than the hearts treated with azathioprine and steroids. Cyclosporine is associated with a higher incidence of interstitial edema and fibrosis than other forms of immunosuppression therapy, and these changes are probably aggravated by rejection.