**7. Treatment of coronary artery bypass graft failure**

Following graft revascularization, patients remain at very high risk for subsequent clinical events. In a large study from the Duke Cardiovascular Databank, patients who underwent catheterization 1 to 18 months after their first CABG were evaluated. [85] Patients were classified on the basis of their worst SVG stenosis as having no (<25%), noncritical (25% to 74%), critical (75% to 99%), or occlusive (100%) SVG disease and the primary outcome measure was the composite of death, MI or repeat revascularization. At 10-years, the corresponding adjusted composite event rates were 41.2%, 56.2%, 81.2%, and 67.1%, respectively (p<0.0001) and most events occurred immediately after catheterization in patients with critical and occlusive SVG disease. Multivariate analysis revealed critical, non-occlusive SVG disease as the strongest predictor of composite outcome (hazard ratio 2.36, 95% CI [2.00-2.79], p<0.0001).

Many patients with recurrent stable angina following CABG can be treated medically for their symptoms and risk factor reduction. Evaluation for ischemia is as in other patients with stable angina without prior CABG. However, early diagnostic angiography is suggested as the different anatomic possibilities, i.e. graft stenosis or progression of native vessel disease in nonbypassed vessels can lead to recurrent ischemia. In patients with recurrent angina, ACS, change in exercise tolerance, positive exercise test after CABG, an increased risk for coronary events is observed. [86-88]
