Long-term prognosis and insurability in coronary heart disease

Abstract

Long-term prognosis in the individual patient with coronary heart disease is unpredictable. However, there are broad patterns of survival in the various clinical syndromes which may be expressed in sufficiently quantitative terms to allow an estimate of insurability. Clinical and actuarial studies are surveyed comprising long-term follow-up of groups having: (1) acute attacks of myocardial infarction, (2) angina pectoris, (3) atypical chest pain, (4) asymptomatic electrocardiographic abnormalities, including bundle branch block and T-wave abnormalities, (5) electrocardiographic evidence of coronary insufficiency on performance of exercise or hypoxemia stress tests. Prognosis is expressed most conveniently in terms of mortality ratios (actual to expected deaths), i.e., the relative number in a group succumbing compared to the relative number in the general population of the same age and sex dying in the some period. In most clinical studies the long-term prognosis, i.e., survival after the initial period of acute coronary attacks, has been analyzed in terms of the percentage alive after five and ten years. Mortality in the first two years after a coronary attack is of the order of six to seven times normal (mortality ratio of 600 to 700 per cent). Thereafter it falls progressively, with increasing intervals of time after the attack. Other factors have significant bearing on survival after coronary attacks. The milder the acute attack, the more complete the recovery, and the older the age at which it occurs, the more favorable the long-term outlook. In such groups, life expectancy may far exceed the over-all average experience, which in most studies has been that 3 of 5 persons surviving acute infarction live a further five years, and 1 of 3 survives ten years. Conversely, in persons who have accompanying disorders predisposing to progression of coronary disease, such as diabetes, the long-term outlook is poorer than average. Mortality ratios are somewhat better in persons with angina pectoris than in those who have had known attacks of myocardial infarction, although in one very extensive study the five- and ten-year survival rates were not significantly higher. Long-term prognosis is slightly better in females than in males both in instances of angina pectoris and after coronary attacks. Asymptomatic electrocardiographic abnormalities also have an adverse effect on survival. Mortality in those with major T-wave abnormalities is approximately three and one-half times the normal, and in those with minor T-wave changes it is twice the normal. Bundle branch block, at one time considered an ominous finding, is not (in the absence of accompanying physical impairments) associated with any striking increase in mortality ratios and is prognostically less unfavorable than T-wave abnormalities. Among those who have ischemic electrocardiographic changes after exercise, mortality rates are almost threefold greater than among those with a negative response. Actuarial investigations, as well as epidemiologic studies on the rate of development of coronary heart disease, indicate that the risk of developing overt disease may be multiplied several fold in the presence of various predisposing factors, particularly when multiple factors are present concurrently. Among these are elevated serum cholesterol, obesity, hypertension, diabetes, strong family history of coronary disease, heavy smoking, sustained stressful personality pattern, and arcus senilis. There are indications that the course of coronary heart disease may be modified, and that the pattern of survival may begin to approach that of the average population by controlling some of the predisposing factors, and by application of such measures as dietary restriction of fat and prolonged anticoagulation. Persons with coronary heart disease, of whatever type, as groups, have an abbreviated life expectancy, and the great majority succumb to complications of their coronary disease, most commonly recurrent acute coronary attacks or sudden death, and, more particularly in older persons, congestive heart failure. However, clinical and actuarial experience indicates that long-term mortality ratios following attacks of myocardial infarction and in other syndromes of coronary heart disease are not prohibitive; and insurability may be considered in appropriate circumstances, e.g., at an interval after recovery from acute attack, when functional recovery is good, and when there are no accompanying adverse factors.