Ischaemic heart disease and diabetes

Approximately 30% of patients requiring revascularization for chronic ischaemic heart disease are diabetic. Compared with the general population, their mortality due to ischaemic heart disease is three to five times higher. This is due to the fact that in diabetics the process of atherosclerosis is accelerated. Diabetes mellitus significantly reduces long-term outcomes after percutaneous coronary intervention (PCI), whereas short-term procedural success is the same as for non-diabetics. Recent evidence shows that everolimus-eluting stents have better results in diabetics than other drug-eluting stents. Diabetes is also a risk factor for coronary artery bypass grafting (CABG) and in those diabetics who also suffer from peripheral vascular disease and/or renal failure, survival is even further reduced. A major ongoing trial is testing whether bilateral internal thoracic artery grafting provides enhanced survival compared with single internal thoracic artery grafting. Fear of higher sternal wound complications after bilateral internal thoracic artery grafting in diabetics is not substantiated by currently available evidence. There is, however, clear evidence that strict perioperative glucose control using intravenous insulin infusion improves outcomes after CABG in diabetics. Trials comparing CABG versus PCI in diabetics with multivessel coronary artery disease show that PCI carries a higher risk of long-term death, myocardial infarction, and repeat revascularization whereas rates of stroke are slightly higher after CABG. Therefore, CABG remains the preferred treatment strategy in diabetic patients with stable multivessel coronary artery disease.