['Myocardial rejection is most apt to occur in the first 90 days after heart transplantation. Nevertheless, surveillance endomyocardial biopsies are often performed on a regular basis, indefinitely. The benefit of this approach to patient management is uncertain. Our objective was to determine the frequency of abnormalities and the influence of a routine annual endomyocardial biopsy on patient management.', 'In a consecutive series of 235 transplant recipients who survived 1 year or more, the results of 1123 routine endomyocardial biopsies performed 1 year or more after transplantation were reviewed. The incidence of late rejection, presence of Quilty effect (focal endocardial or myocardial lymphocytic aggregates), and therapeutic reaction to the biopsy result were analyzed.', 'Of 1123 biopsy specimens in 235 patients (1 to 12 years after transplantation), 1115 (99.3%) showed no evidence of significant rejection (grade 0 or 1). Only seven (0.6%) had evidence of rejection grade 2 or worse. Of the seven abnormal biopsy specimens in seven patients, two occurred at 1 year, two at 2 years, and one each at 4, 7, and 8 years. Of these, six were treated for rejection with an increase in the immunosuppressive therapy. One patient was identified as having a symptomatic condition at the time of biopsy. A focal endocardial or myocardial accumulation of lymphocytes (Quilty effect) was present in 311 biopsy specimens (27.6%). Beyond 1 year, 33 patients died, 14 because of graft vascular disease with or without rejection and 19 because of other causes. No deaths were predicted on the basis of a routine surveillance biopsy.'] Are routine surveillance myocardial biopsies unnecessary beyond one year after heart transplantation?