Abstract
A total of 142 saphenous vein bypass patients who underwent pre- and postoperative treadmill stress tests were analyzed. The double product at the onset of ischemia improved in 15 of 25 females (68%) and 67 of 117 males (58%). In patients with a history of preoperative angina, 103 of 132 (78%) were relieved after operation, but only 81 of 132 (61%) improved their double product. In those with preoperative angina during treadmill stress testing, 48 of 79 (61%) improved. In patients without preoperative angina on treadmill stress testing, 40 of 65 (62%) improved their double product. When ST depression developed at a workload of 4 METS on the preoperative treadmill stress test, 54 of 87 (62%) improved. When ST depression developed at 6 METS, 20 of 34 (58%) improved their double product at the point of ischemia.
The patient's sex, angina during treadmill stress testing, and the workload associated with ischemia did not help identify those who would benefit from bypass surgery. Treadmill stress testing does demonstrate the disparity be tween symptomatic and functional improvement and provides an important parameter for evaluation of aortocoronary bypass.
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