It is well recognized that DM is a powerful risk factor for poor early and late outcome after CABG surgery. Further, DM is an important predictor of subsequent saphenous vein graft occlusion as well as progression of atherosclerosis in both bypassed and nonbypassed vessels.
As described previously, the BARI trial has shown that patients with DM and angiographic multivessel CAD randomized to an initial strategy of CABG surgery have a striking reduction in mortality compared to diabetic patients randomized to balloon PCI. Further, post hoc analyses of three smaller trials comparing CABG with balloon PCI in patients with stable CAD demonstrated potentially conflicting results in diabetic subjects. In the CABRI trial, diabetic patients fared worse in a manner similar to that seen in BARI. By contrast, the RITA-1 and EAST trials demonstrated similar outcomes in diabetic patients treated with CABG or balloon PCI.
Results from retrospective studies and registries bear on the role of CABG in diabetic subjects. A caveat in the interpretation of these results is that such databases of diabetic patients who have undergone coronary intervention may not be generalizable to more unselected groups. Further, the prognosis in such nonrandomized cohorts can be influenced by physician practice patterns and potential bias regarding the selection and choice of intervention. These limitations aside, however, there are two sizeable databases that have evaluated clinical outcomes among diabetic and nondiabetic patients treated with PCI or CABG surgery. In the Emory University study, only insulin-requiring diabetic patients treated with balloon PCI demonstrated lower 5- and 10-year survival compared with the CABG-treated patients. In the large Duke University registry, DM was associated with a significantly worse 5-year survival, but the effect of DM on prognosis was similar in both revascularization strategies.
In patients undergoing CABG surgery, the long-term patency of internal mammary artery (IMA) conduits to the left anterior descending coronary artery compared to autologous saphenous vein grafts (SVGs) has been shown to be unquestionably superior. It is thus not surprising that the results of the BARI trial, which showed the benefit of CABG over balloon PCI in diabetics, was confined to those patients who had at least one IMA graft. Whether bilateral IMA -o grafts afford additional benefit in diabetic patients is unknown, especially since this technique may be associated with a greater risk of sternal wound complications in diabetic patients.
In summary, the superiority of CABG surgery over angioplasty in diabetics with symptomatic CAD, as was observed in the BARI trial, has not been definitively established. These findings represent a post hoc analysis, and neither stents
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Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...