HOW MANY ENDOMYOCARDIAL BIOPSIES ARE NECESSARY IN THE FIRST YEAR AFTER HEART-TRANSPLANTATION

Since 1989, the immunosuppressive regimen used in all heart transplant (HTx) patients at our center has consisted of a combination of cyclos porin, azathioprine, and prednisone. No prophylactic cytolytic agents have been given. One hundred consecutive patients were followed for pe riods of 4-56 months (mean 27 months). The incidence of rejection was so low in the initial 18 patients that we felt confident about reducin g the number of routine endomyocardial biopsies (EMBs) that were perfo rmed. The mean number of EMBs in this subgroup was 10 (median 11). In the next 20 patients, EMB was performed routinely on only three occasi ons during the 1st post-transplant year (at 2, 4, and 8 weeks). In the subsequent 62 patients, EMB was performed on post-transplant days 10, 20, 30, and 60. Further EMBs were performed after acute rejection epi sodes had been treated. No noninvasive methods of diagnosing rejection were employed. In 82 consecutive patients, therefore, the mean number of EMBs within the 1st year was five per patient (median four), with 58% undergoing fewer than five EMBs and 25% requiring more than five E MBs. In the entire group of 100 patients, the mean number of EMBs was 5.9. The incidence of acute rejection requiring increased therapy was 24%. Only 7% required i.v. steroids, two of whom (2%) also required AL G and/or OKT3, with 17% requiring increased oral immunosuppression alo ne. Actuarial survival was 98% at 30 days, 94% at 1 year, and 92% at 2 years. It is possible that we may have missed acute rejection episode s that resolved spontaneously. However, the excellent medium-term resu lts would suggest that any such rejection episode did not progress to become hemodynamically significant. It may be, therefore, that when an effective immunosuppressive regimen is utilized, the number of EMBs p erformed at many centers is excessive.