This investigation was performed to study the reasons for receiving disability pension after aortocoronary bypass surgery. During the period March 1983 to November 1985, 250 patients underwent aortocoronary bypass surgery. At a mean follow-up of 4.9 years (range 3.6-6.7) after the operation, 31 patients were dead. Of the 219 survivors, all except four underwent a follow-up examination including an exercise test. The mean physical work capacity had increased from 92.2 W preoperatively to 119.3 W at follow-up (p