Sudden death: lessons from subsets in population studies.

Sudden coronary death is an important feature of clinical coronary disease, the incidence doubling with each decade of age after age 45 and with women lagging behind men in incidence by 20 years. Fifty percent of the sudden deaths in men and 64% in women occur in persons without prior coronary heart disease, and 18% of coronary attacks in men and 24% in women present as sudden death. More than half of coronary mortality is in the form of sudden death. Persons with overt established coronary heart disease are at 3-fold to 12-fold increased risk depending on age, the risk ratio diminishing with advancing age. When overt coronary disease is established, the major coronary risk factors have little discernible effect on the risk of sudden death. Risk appears related chiefly to the degree of myocardial damage as indicated by electrocardiographic abnormality and evidence of cardiac failure. In subjects free of overt coronary heart disease, the risk of sudden death varies widely in relation to risk factors, including systolic pressure, serum cholesterol, vital capacity, cigarette smoking, relative weight, heart rate and electrocardiographic abnormality. Multivariate combination of these risk factors allows an efficient prediction of sudden death in both sexes. The key to the prevention of sudden death in the general population is to prevent coronary attacks by avoidance or correction of the aforementioned risk factors. No risk factors thus far identified are clearly specific for sudden death.(ABSTRACT TRUNCATED AT 250 WORDS)