Pathogenesis and prevalence of atherosclerosis in hypertensive patients

Abstract

Atherosclerosis is important because of its complications that include, for example, myocardial infarction, angina pectoris, stroke, aortic aneurysm, and intermittent claudication. Prospective studies have indicated that the risk-factor patterns for these complications are different in various parts of the cardiovascular tree. For stroke, hypertension is quantitatively the most important risk factor whereas, for intermittent claudication, smoking appears to be by far the most important risk factor. Myocardial infarction, however, is a complication for which a large number of risk factors emerge and none appears to be more important, at least from the statistical point of view, than the others. The prevalence of the different types of complications of atherosclerosis varies considerably among countries. Despite a high prevalence of stroke in Japan and a prevalence of hypertension equal to that in the United States, the prevalence of myocardial infarction is low. This indicates that the importance of hypertension as a risk factor for myocardial infarction is dependent on the presence of other risk factors, such as hypercholesterolemia. In the United States and several European countries, for instance Sweden, there has been a dramatic reduction in the yearly incidence of stroke since the beginning of the 1950s. The time sequence for this change and the change in the number of patients treated for hypertension have been similar in both the United States and Sweden. In contrast, the decrease in the incidence of myocardial infarction began about 15 years later in Sweden than in the United States. In Sweden, the reduced incidence of stroke can be explained by the reduction in the incidence of hemorrhagic stroke only.(ABSTRACT TRUNCATED AT 250 WORDS)