Kim Wilson BSc, MSc and Geriatrics & Aging Staff

A myocardial infarction (MI) is generally caused by a thrombus obstructing a coronary artery, resulting in death of heart muscle. Thrombi are usually caused by rupture of an atherosclerotic plaque on the wall of the coronary artery. About 50% of patients hospitalized for an acute myocardial infarction are elderly.¹ The majority of patients who develop complications (such as congestive heart failure) or die from their first MI are also over the age of 65. Clearly coronary artery disease is a significant cause of morbidity and mortality in seniors.

Primary prevention refers to risk factor modification to prevent a first MI, and includes education, lifestyle changes, and possibly pharmacological therapy in both younger and older men and women.

D'Arcy L. Little, MD
Chief Resident, Family Medicine, Sunnybrook Health Science Centre, North York, Ontario.

The proportion of the population over the age of 65 is growing rapidly. Currently over 12% of the population is in this age category, and by the year 2016 this proportion will increase to almost 16% (Statistics Canada). The incidence of coronary heart disease increases with age and is the leading cause of death among the elderly. In addition, elderly patients have on average a fourfold greater mortality from first and subsequent acute myocardial infarctions (AMI) than do younger patients. As summarized by Milzman in "An Introduction to Resuscitating the Ages" (Emergency Medicine Clinics of North America, February 1996) and Rich in "Therapy for Acute Myocardial Infarction" (Clinics in Geriatric Medicine, February 1996), some of this mortality can be attributed to age, as it is an independent negative predictive factor, and to various co-morbid illnesses which often accompany age. However, recent studies indicate that much of the increase in morbidity and mortality incurred by the elderly patient experiencing an AMI may be related to under-aggressive resuscitation and management.

ABCs

The presentation of AMI in the elderly is influenced by age-related changes and pre-existing disease.