ABSTRACT

Coronary atherosclerosis is essentially a chronic progressive disease, and, in patients with coronary atherosclerosis, progression of the disease is one of the major factors determining clinical prognosis.1-3 Some lessons about the dynamics of coronary atherosclerosis were already learned from observational studies in the second half of the twentieth century. These studies were defined as studies based on observations in regular patient populations. Typically, the patients have not been subjected to a specific intervention, and the studies are basically retrospective. Sometimes the term ‘natural history’ is used, but this is only appropriate if ‘natural history’ is defined as the evolution of the disease under usual treatment, in the case of coronary disease excluding mechanical interventions (bypass surgery and catheter coronary artery disease (or any other disease)) because ‘it is the function of the physician to make the history as desirably unnatural as possible’.4