Coronary Heart Disease Risk in People 65 Years of Age and Older

William B. Kannel, MD, MPH, Barbara S. Levine, PhD, CRNP, CS

Disclosures

Prog Cardiovasc Nurs. 2003;18(3) 

In This Article

Abstract and Introduction

Evidence from epidemiologic studies indicates that the same factors that are associated with increased risk of coronary heart disease (CHD) in middle-aged people are relevant in older adults (i.e., those aged ≥65). The relative risk associated with some risk factors decreases with advancing age but this is offset by greater incidence of CHD among older adults. A growing body of evidence from clinical trials indicates that risk factor modification in older adults reduces CHD risk as effectively as it does in middle-aged adults. Multivariable risk assessment can be used to effectively target intervention to those at significant for an initial CHD event and to avoid over-treatment. It is important to appreciate that the average remaining life expectancy after achieving 80 years is about 8 years.

Despite declines in coronary heart disease (CHD) mortality rate, CHD remains a serious concern among older adults because of the increased number of people living beyond 65 years.[1] The number of older adults and their high rate of CHD mortality and disability, together with the increasing information available to guide health care clinicians warrants a review of the current status of modifiable CHD risk factors. Clinicians may question whether prolonged exposure to risk factors can be countered late in life, and whether there is enough time left for preventive measures to take effect and be worth the effort. In this regard, it is important to appreciate that the average life expectancy, even after attaining age 80 years, is about 8 years.

The major correctable independent risk factors for CHD are cigarette smoking of any amount, hypertension, elevated serum total cholesterol and low-density lipoprotein cholesterol (LDL-C), reduced serum high-density lipoprotein cholesterol (HDL-C), and diabetes mellitus. Relative risk is the ratio of the absolute risk of an individual (or group) with the risk factor to that of a low-risk group (those without the risk factor). For example, the relative risk associated with hypertension is 1.6 in men aged 65-94 years. This means that, other factors being equal, older men with hypertension have a 60% greater risk for developing CHD or experiencing a CHD event than older men with normal blood pressures. If this 60% greater risk meant a difference of 1:100,000 to 1.6:100,000 this would not be very important. Given the high prevalence of CHD among older men (18.6% in men >75 years), the increased relative risk is important. Absolute risk is the probability of developing a new CHD event (i.e., myocardial infarction [MI], unstable angina or death) over a given time period. From the individual's perspective absolute risk is much more important than relative risk.

Epidemiologic studies of CHD risk factors indicate that modifiable risk factors that are relevant for middle-aged adults are also relevant at older ages.[2,3] The relative risk associated with some factors (total cholesterol, high blood pressure, electrocardiographic evidence of left ventricular hypertrophy [LVH], and cigarette smoking) appears to decline with advancing age. The apparent decline in potency of CHD risk factors with advancing age may be explained, in part, by the progressive elimination of susceptible persons from the population.[4] Also, because risk factors that are measured late in life often do not reflect the lifetime level of exposure, their impact appears to be attenuated.[5] Older people may have made positive lifestyle changes such as quitting smoking or losing weight after many years of exposure to the adverse effect of these risk factors. The apparent decline in potency of CHD risk factors causes an unjustified reluctance to intervene, failing to recognize that the reduction in relative risk is offset by a greatly increased absolute risk. The high prevalence of CHD in older people makes risk factor control more cost effective in older than in middle-aged people.

Subclinical, severe coronary artery pathology is present in one half the older adults in affluent countries, blurring the distinction between primary and secondary prevention. Older adults with overt CHD are clearly appropriate targets for aggressive risk reduction. High-risk older adults without known CHD are also legitimate candidates who can be efficiently targeted for treatment through multivariable risk assessment, avoiding needless over-treatment. The recent decline in CHD mortality includes older adults, indicating that CHD is not an inevitable or unchangeable consequence of aging.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....