High-risk reparative surgery. A neglected alternative to heart transplantation. The selection of patients for either high-risk reparative operations on the heart or for transplantation has become increasingly difficult as a result of improved results with both modalities. A retrospective review was done of patients referred for heart transplantation who were not considered candidates for conventional cardiac surgery, yet instead underwent reparative procedures rather than transplantation. Of 23 adult patients referred during a 7-year period, 18 had coronary artery disease, and five had valvular heart disease. All had New York Heart Association class IV symptoms. Preoperative left ventricular ejection fractions were in the range 0.08-0.63 (mean, 0.28). Ten of 18 patients with coronary artery disease required insertion of an intra-aortic balloon pump for hemodynamic support perioperatively. Seven patients had primary coronary artery bypass grafts, and 10 had reoperative coronary bypass procedures. One patient had a left ventricular aneurysmectomy, and one had endocardial stripping in addition to myocardial revascularization procedures. Of the patients with valvular disease, three had aortic valve replacement, of which two were reoperations, and two others had mitral valve replacements with tricuspid annuloplasties. With a mean follow-up of 25 months, 1-, 3-, 12-, and 24-month actuarial survival rates were 91%, 87%, 82%, and 76%, respectively. One patient who underwent aortic valve replacement in this study successfully received heart transplantation 19 months postoperatively. These results compare favorably with the current results for patients undergoing first-graft heart transplantation. All survivors enjoy New York Heart Association class I or II functional capacity. 