The Annals of Thoracic Surgery, Vol 35, 29-35, Copyright © 1983 by The Society of Thoracic Surgeons
Postoperative treadmill performance and graft patency after myocardial revascularization
RA Cukingnan Jr, JS Carey and BG Brown
In a prospective study, a random selection of 122 patients who had coronary
artery bypass grafting were studied angiographically and given treadmill
tests preoperatively and one year after operation, regardless of their
symptoms. A total of 397 grafts were performed (average, 3.3 grafts per
patient) on all primary and secondary coronary vessels deemed graftable.
Complete coronary revascularization (grafts to vessels 1.5 mm or more in
diameter with 50% or greater stenosis) was achieved in 104 patients (85%);
18 patients (15%) were considered incompletely revascularized. One hundred
sixteen of the 397 grafts (29%) were to the left anterior descending (LAD)
coronary artery, 99 (25%) to the right coronary artery, 126 (32%) to the
obtuse marginal branch, 52 (13%) to the diagonal branch of the LAD coronary
artery, and 4 (1%) to the septal coronary arteries. Overall results showed
that patients with positive postoperative treadmill tests had a graft
patency of 64%, compared with 86% for patients with negative treadmill
tests (p less than 0.001). Completely revascularized patients with all
grafts patent had a 4.8% (3/62) incidence of positive treadmill
performance, compared with 60% (6/10) for incompletely revascularized
patients with all grafts patent (p less than 0.001). Completely
revascularized patients with positive treadmill tests had a graft patency
of 58% (45/78), while those with negative treadmill evaluations had a graft
patency of 86% (227/264) (p less than 0.001). The patency rate for
incompletely revascularized patients with positive treadmill performance
was 78% (25/32) and 87% (20/23) for those with negative treadmill
performance. This difference was not statistically significant. This study
shows that postoperative treadmill performance is highly dependent on
completeness of revascularization and graft patency. It therefore supports
the prognostic importance of regular treadmill exercise testing to monitor
continued graft patency.