A Hazard Of Hearts [PORTABLE]
The epidemiologic approach to investigation of atherosclerotic cardiovascular disease has provided many insights into the preclinical and clinical spectrum of the disease. The hazard of developing atherosclerotic cardiovascular disease is substantial with coronary heart disease (CHD), the most common and most lethal feature. The outlook in those who manage to survive the initial episode is also serious, with a 10-year mortality rate of 37% for persons with angina and a 55% rate for those sustaining a myocardial infarction. Fifteen percent of persons developing CHD present with a fatal event, and 38% of infarctions go unrecognized. The presence of atherosclerosis in one vascular territory imposes an increased risk of its appearing in another area at two to six times the general population rate. The major cardiovascular risk factors adversely affect all arterial vascular territories so that correction of risk factors targeted at one particular atherosclerotic outcome may also favorably influence the other risk factors. Coronary disease is the most prevalent lethal hazard of hypertension, dyslipidemia, glucose intolerance, and cigarette smoking. These risk factors cluster and optimal therapy must improve the whole risk profile. Women share the same risk factors for CHD as men. Although women have a lower absolute risk for most risk factors, a high total/HDL cholesterol ratio, left ventricular hypertrophy, and diabetes each tend to eliminate the female advantage. Menopause also promptly escalates risk threefold. Although women tend to have a lower incidence than men, the initial attack is just as highly lethal in women, and their subsequent outlook as survivors is at least as serious as for men. Sudden death is a pre-eminent feature of coronary disease and cardiac failure. Coronary disease increases sudden death risk 3.3-fold and cardiac failure 4.8-fold. Sudden death incidence varies in relation to the same cardiovascular risk factors as coronary heart disease, with no unique risk factors identified. However, multivariate combinations of these in a profile can identify high-risk candidates for sudden death as well as coronary attacks in general. The key to prevention of sudden death is to prevent coronary attacks and cardiac failure. Despite aggressive cardiac revascularization and treatment of hypertension, congestive heart failure (CHF) has not decreased in prevalence, and innovations in the treatments of overt failure have not substantially improved survival. Median survival is only 1.7 years for men and 3.2 years for women. The conditional probability of developing CHF can be estimated using a logistic function comprised of age, systolic pressure, vital capacity, heart rate, ECG-left ventricular hypertrophy (LVH), glucose intolerance, x-ray enlargement, and presence of CHD and heart murmurs. Eighty percent of CHF events occur in persons in the upper quintile of multivariate risk. Continued clinical, metabolic, and epidemiologic research have expanded and refined atherosclerosis risk factors. The lipid connection is now concerned with the apoprotein makeup of the lipids, subfractions of lipids, and Lp(a). The diabetic influence is now focused on insulin resistance. Ambulatory monitoring is being used to evaluate blood pressure and silent ischemia. Fibrinogen and leukocyte counts have emerged as possible indicators of unstable lesions. Prospects for primary and secondary prevention are good if public health measures, health education, and preventive medicine are implemented based on existing knowledge of correctable or avoidable risk factors. The potential for more effective prevention continues to expand, and great advances have already been made in countries where aggressive preventive measures have been implemented to correct the major established risk factors.
A Hazard of Hearts