Long-term follow-up data from BARI, EAST, and CABRI indicate that after PCI, progression of coronary disease in diabetics is accelerated compared to nondia-betics both at the treated site and in untreated sites (26-28). Although cholesterol lowering did not prove efficacious in reducing post-PCI restenosis in the Lova-statin restenosis trial (71), multiple beneficial effects of cholesterol-lowering therapy have been documented in this population with coronary disease including improved endothelial function and reduced cardiac events (72). More specific to the diabetic patient, in the 4S study, lowering cholesterol resulted in reduced cardiac events (11), inducing a reduction in 5-year mortality that was greater in diabetics than in nondiabetics (43% vs. 29% decrease) (73). A greater benefit in diabetics treated with HMG COA reductase inhibitors was also observed in the CARE and LIPID trials (74,75). In diabetics undergoing stent implantation, use of statins was associated with reduced clinical events and attenuation of neointimal proliferation that appeared in part independent of their cholesterol-lowering properties (76). Statins are currently regarded as first-line drugs in diabetics with elevated levels of LDL cholesterol following PCI.
Abundant data are present in the literature to confirm an important role of elevated serum lipids including LDL cholesterol, HDL cholesterol, triglycerides, apolipoprotein B, and Lp(a) in the development of saphenous vein graft athero- g sclerosis leading to late cardiac events after bypass surgery (77-83). The recently <j reported Post-Coronary Artery Bypass Graft (Post-CABG) trial showed that ag- Ji gressive therapy to lower serum cholesterol led to a reduced progression of atherosclerosis in saphenous vein grafts (84) and this study has major implications a for the post-CABG patient. Further analysis of prognostic factors for atheroscle-
& u rosis progression in saphenous vein grafts in patients in the post-CABG trial identified current smoking, male sex, hypertension, elevated triglycerides, and low HDL as independent predictors of graft worsening (85). The importance of vein graft atherosclerosis in the diabetic population was graphically emphasized in BARI where the 7-year survival of diabetic patients treated with CABG using only saphenous vein grafts was only 54% compared to 83% for patients receiving at least one LIMA graft (see Fig. 6). It is clear, based on BARI and previously reported work (22,34), that diabetics after CABG have a reduced longevity compared to nondiabetics, especially when dependent on saphenous vein grafts. Aggressive measures are indicated in all post-CABG patients to reduce serum LDL, elevate HDL, control blood pressure, lower triglycerides, and strongly encourage smoking cessation. The effects of rigorous glycemic control on cardiac events post-CABG have not been carefully studied.
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