Methods for detecting coronary disease: epidemiology and clinical management

The epidemic of atherosclerotic disease in wealthy countries had probably begun by 1900. Although a few physicians understood how atherosclerosis/thrombosis of the coronary arteries caused angina pectoris and myocardial infarction, the medical community did not accept that relationship until the 1920s. In wealthy countries, the epidemic peaked in mid-century, and it is now advancing in poor countries and in countries becoming affluent. Two recent developments in methods for disease detection, however, will profoundly affect not only our understanding of the epidemic of atherosclerotic disease, but also our management of patients. A redefinition of the clinical diagnosis of myocardial infarction, a well-used but imperfect measure of the epidemic, was published in September 2000. Criteria employed for about 50 years have now been replaced by criteria based on sensitive biochemical markers of necrosis of as little as 1 g of myocardium, accompanied by chest discomfort or electrocardiographic (ECG) changes, or following coronary artery intervention. The new criteria, adopted by the major societies of cardiology in Europe and the United States, is likely to increase the apparent incidence and prevalence of coronary heart disease (CHD). In the beginning of the twentieth century, diagnosis of CHD required an autopsy. In the end it was carried out by angiography as well, but it could not be applied to large proportions of the population. That has now been changed by new, non-invasive methods of computer tomography (CT) and magnetic resonance imaging (MRI), and patients, however, asymptomatic, will expect treatment for a disease that physicians have detected. Coronary artery disease (CAD) will be to CHD what occult cancer is to cancer.