ABSTRACT
THE PROBLEM Coronary heart disease is common. It is responsible for over 110,000 deaths in the United Kingdom each year (1). There are 1.4 million people with angina in the United Kingdom. It is inevitable that many patients who present for major surgery will have a history of ischemic heart disease. In addition to patients with overt ischemic heart disease is a significant population of surgical patients who have occult coronary artery disease. This is perhaps best exemplified by the asymptomatic diabetic patient, who is at high risk of adverse perioperative cardiovascular events such as death, myocardial infarction (MI), or episodes of severe heart failure following elective surgery. There are many scoring systems for identifying those at high risk of perioperative MI (2-4). Table 1 has a simplified system divided into factors that greatly increase the risk, factors that moderately increase the risk, and factors that slightly increase the risk. The only factor that has been associated with a reduction in risk is having a success of coronary artery bypass grafting within the previous six years. A particular problem is that of surgery soon after intracoronary stenting, particularly when a drug-eluting stent has been used. These stents reduce restenosis rates, but delays endothelium coverage making the stent extremely vulnerable to thrombosis if antiplatelet therapy is interrupted for major surgery. A recent study suggests that elective surgery should be delayed for at least three months after stenting and some people opine the delay should be 12 months (5). It should be remembered that three or more moderate risk factors in the same patient equate to a high risk of adverse perioperative cardiovascular events or death. For example, a 75-yearold diabetic patient undergoing a hemicolectomy is a high-risk patient even if there are no symptoms of cardiovascular disease and the ECG is normal.
