Therapy for Acute Myocardial Infarction

Cardiovascular Disease Risk Reduction in Older Adults

Preventing cardiovascular events in older persons presents unique challenges to clinicians. Cardiovascular disease accounts for a large amount of disability and mortality in older persons. Older persons are often faced with unique and multiple challenges to health, including cognitive decline, social isolation, financial constraints, and physical disabilities. As more and more older persons are enrolled in studies that aim to better understand coronary heart disease and its prevention, new information is becoming available that allow clinicians to improve outcomes in the older adult. The most recent updates in the area of medical management, as well as updates of recommendations for lifestyle changes, including physical activity and dietary recommendations for older persons at risk, are presented in this article.

Metabolic syndrome and the risk of cardiovascular disease in older adults

OBJECTIVES

The purpose of this study was to assess whether metabolic syndrome (MetSyn) predicts a higher risk for cardiovascular events in older adults.

BACKGROUND

The importance of MetSyn as a risk factor has not previously focused on older adults and deserves further study.

METHODS

We studied the impact of MetSyn (38% prevalence) on outcomes in 3,035 participants in the Health, Aging, and Body Composition (Health ABC) study (51% women, 42% black, ages 70 to 79 years).

RESULTS

During a 6-year follow-up, there were 434 deaths overall, 472 coronary events (CE), 213 myocardial infarctions (MI), and 231 heart failure (HF) hospital stays; 59% of the subjects had at least one hospital stay. Coronary events, MI, HF, and overall hospital stays occurred significantly more in subjects with MetSyn (19.9% vs. 12.9% for CE, 9.1% vs. 5.7% for MI, 10.0% vs. 6.1% for HF, and 63.1% vs. 56.1% for overall hospital stay; all p < 0.001). No significant differences in overall mortality was seen; however, there was a trend toward higher cardiovascular mortality (5.1% vs. 3.8%, p = 0.067) and coronary mortality (4.5% vs. 3.2%, p = 0.051) in patients with MetSyn. After adjusting for baseline characteristics, patients with MetSyn were at a significantly higher risk for CE (hazard ratio [HR] 1.56, 95% confidence interval [CI] 1.28 to 1.91), MI (HR 1.51, 95% CI 1.12 to 2.05), and HF hospital stay (HR 1.49, 95% CI 1.10 to 2.00). Women and whites with MetSyn had a higher coronary mortality rate. The CE rate was higher among subjects with diabetes and with MetSyn; those with both had the highest risk.

CONCLUSIONS

Overall, subjects over 70 years are at high risk for cardiovascular events; MetSyn in this group is associated with a significantly greater risk.

Hypertension in the Elderly

Elderly individuals with hypertension show specific characteristics as a result of advancing arteriosclerosis, a high frequency of isolated systolic hypertension, increased pulse pressure and orthostatic hypotension. The necessity to treat hypertension in the elderly, including isolated systolic hypertension, has been demonstrated in many large-scale intervention trials. Young-old (65-74 years of age) hypertensive patients should be treated the same as nonelderly hypertensive patients. In old-old (75-84 years of age) patients with mild hypertension (140-159/90-99 mm Hg), the recommended target blood pressure (BP) is <140/90 mm Hg. In old-old (75-84 years of age) and oldest-old (> or =85 years of age) patients with systolic BP > or =160 mm Hg, cautious treatment is required. An intermediate target BP of <150 mm Hg is appropriate, followed by a final target BP of <140 mm Hg, if tolerated. Nonmedical therapy, such as salt restriction, exercise and weight reduction, is useful in the elderly. However, individualised management of nonmedical therapy is necessary to avoid deterioration of quality of life resulting from strict management of the patient's lifestyle. Diuretics, calcium channel antagonists, ACE inhibitors and angiotensin II type 1 receptor antagonists have been established as first-line antihypertensive drugs in the elderly. Use of combination therapy helps to achieve target BPs. The starting dose of each drug should be half the usual dose for nonelderly patients, and may be increased at intervals of >4 weeks, with achievement of the target BP in 3-6 months or longer. In hypertensive patients with co-morbid diseases, the target BP should be determined individually and antihypertensive drugs selected bearing in mind the patient's clinical circumstances. Avoiding hypoperfusion of target organs is very important in elderly hypertensive patients. When treating hypertension in elderly patients, the approach should be to identify individual pathophysiological characteristics and lower the BP cautiously and slowly.

Secondary prevention of coronary heart disease in the elderly

OBJECTIVE

To review relevant literature supporting the use of aspirin, beta-blockers, lipid-lowering agents, and angiotensin-converting enzyme (ACE) inhibitors for the secondary prevention of coronary heart disease (CHD) in an elderly patient population aged >/=65 years.

DATA SOURCES

A MEDLINE search (1990-May 2003) was conducted using the key terms coronary heart disease, secondary prevention and elderly.

STUDY SELECTION AND DATA EXTRACTION

Primary and tertiary literature relating to the use of aspirin, beta-blockers, lipid-lowering agents, and ACE inhibitors in the elderly were reviewed.

DATA SYNTHESIS

CHD is the leading cause of morbidity and mortality in persons >/=65 years of age, and the use of pharmacologic agents has created a considerable opportunity for reducing recurrent events in those with established disease. This, combined with the aging of the US population, is creating an increase in the number of older adults eligible for secondary prevention. In 2002, the American Heart Association issued a scientific statement on the benefits of specific secondary prevention risk factor interventions in older adults. This article reviews pertinent findings from this statement, along with additional data supporting the use of pharmacologic agents for the secondary prevention of CHD in the elderly.

CONCLUSIONS

Data suggest that use of aspirin, beta-blockers, lipid-lowering agents, and ACE inhibitors are effective in secondary prevention of CHD in individuals aged >/=65 years. This benefit is similar to, and often greater than, that observed in younger patients. We believe that these agents should be prescribed for all elderly patients without contraindications. Ongoing studies and future clinical trials will more clearly elucidate the benefits of secondary prevention of CHD, particularly in persons >/=75 years of age, to determine the magnitude of benefits that can be achieved in this population.

Underlying mechanisms of impaired visceral pain perception in older people

There is increasing recognition that aging can have a profound effect on the presentation of illness. Older patients with diseases of visceral organs are much more likely than younger adults to present atypically. Examples are the frequent absence of pain in older patients with conditions such as myocardial infarction, peptic ulcer disease, and pneumothorax. Recent developments have helped elucidate the complex processes involved in signaling information from the effects of noxious stimuli on visceral organs, but understanding of why older patients with visceral disease are more likely to present without pain is still rudimentary. Much of the previous experimental evidence on age-related differences relates to somatic rather than visceral sources of pain. As a result, it may not have direct comparability with transmission of information on visceral damage or noxious stimulation. This article reviews the published pathophysiological data on sensory transmission from visceral organs. Where possible, this is correlated with other published clinical studies on age-related differences in visceral pain perception. Areas in which experimental evidence is absent are also highlighted. Finally suggestions are made as to how newer experimental and neuroimaging techniques may help to increase understanding of this complex subject and its resulting clinical applicability.

Cardiovascular drug therapy in the elderly: theoretical and practical considerations

The elderly population is expanding rapidly throughout the world. Hypertension, heart disease and other cardiovascular disorders are prevalent conditions among this age group. Consequently, clinicians will spend a large proportion of their practices managing older adults with cardiovascular disorders. A large proportion of this time will be devoted to using pharmacotherapeutic strategies for the long-term management of chronic conditions. The physiological changes that accompany aging affect cardiovascular function, and the pharmacokinetics and pharmacodynamics of many cardiovascular medications are altered by these physiological changes. The interactions of these changes can have a profound effect on the agents used to treat cardiovascular disorders and may alter their therapeutic outcomes. Several classes of medications are used to treat chronic cardiovascular disorders in older adults. These include the ACE inhibitors and angiotensin II receptor antagonists, calcium channel antagonists, beta-adrenoceptor antagonists (beta-blockers), oral antiarrhythmic agents and warfarin. Drugs such as beta-blockers may aggravate decreased cardiac output and increase peripheral resistance, but are valuable adjuncts in many patients with congestive heart failure. Agents that reduce angiotensin II activity may have several benefits for treating heart failure and hypertension. Successful treatment of cardiovascular disorders in older adults requires the choice of the most appropriate agent, taking into consideration the complex interactions of pharmacokinetics, pharmacodynamics and disease effects.

GENERAL PHARMACOLOGIC TREATMENT OF ACUTE MYOCARDIAL INFARCTION

The general pharmacotherapeutic issues surrounding AMI are complex and expanding, especially with regard to treatment aimed at the [table: see text] culprit, coronary atherosclerotic thrombus. Basic, well-established therapy includes the routine administration of oxygen, nitroglycerin, aspirin, and at times morphine, with selected cases invoking caution with respect to these agents (e.g., nitroglycerin and the risk of hypotension in right ventricular infarction; contraindication to nitrolycerin in patients on sildenafil). Cardioprotective agents, especially beta-adrenergic antagonists, should be considered early in light of their demonstrated benefit; others, such as ACE inhibitors, need not be administered in the ED. Heparin, both UFH and the newer LMWHs, have well-established roles in acute coronary syndromes. The GP IIb/IIIa inhibitors are the most recent addition to the pharmacologic armamentarium; their role is evolving rapidly as research on this frontier continues. Table 2 reviews recommended dosing of selected agents in acute coronary syndromes.

Ischemic Heart Disease in the Elderly:A Need to Understand the Causes of High Mortality After Acute Myocardial Infarction

The short- and long-term mortality of patients greater than 75 years of age with acute myocardial infarction is still very high. These patients have been excluded from most randomized controlled trials designed to test interventions directed to improve the outcome of acute myocardial infarction. Contrary to young-old patients (65-74 years) in whom the benefit obtained with these interventions is even greater than that observed in younger patients, there is a lack of information concerning the optimal treatment of acute myocardial infarction in the oldest patients. Research specifically directed to assess the optimal reperfusion strategy and coadjuvant therapies in patients greater than 75 years old is critically important. The causes for such high mortality are still poorly understood. Several clinical observations suggest that old patients with acute myocardial infarction have specific pathophysiologic behaviors. As the knowledge of the mechanisms of disease is, in clinical practice, the basis of therapy development, clinical and basic research designed to elucidate the specific pathophysiological mechanisms and causes of the high mortality in the oldest patients with acute myocardial infarction should be regarded as a priority in geriatric cardiovascular research. (c) 2000 by CVRR, Inc.

Coronary heart disease. Stable and unstable syndromes

CHD in the elderly population will continue to be a source of major concern because of the increasing costs entailed and uncertainties about how the widespread array of diagnostic and therapeutic interventions, often expensive and sometimes hazardous, should be applied. Financial, political, and health policy decisions will continue to occupy much attention, but it is likely that philosophic considerations about aging and death, both from the individual and the societal perspective, will be of paramount importance of deciding how the substantial resources available to the elderly will be used. Randomized, controlled trials are unlikely to play a major role in resolution of management dilemmas in the elderly because of the extraordinary heterogeneity in this population. Registries (databases) involving carefully prospectively collected key variables are likely to be a more effective approach. Critical characterization of complications of procedures, adverse drug reactions, and collection of follow-up data on functional status are among the critical questions, and these can be answered by registry studies. Algorithms and clinical rules developed in younger cohorts are not directly transferable to the elderly cardiovascular patients, further emphasizing the need for prospectively collected, syndrome-specific data. Treatments convincingly demonstrated to reduce mortality in absolute terms more in the elderly than in the young are underused. The heterogeneity of aging emphasizes the wide variability in patients' ability to withstand the stress of procedures and complications of disease and makes clear the need to consider physiologic reserve and biologic age rather than chronology. With better characterization of biologic age and physiologic reserve, more precise estimates of outcomes of therapies and interventions can be made, and patients can be given better information and with their families have more realistic expectations. Better-informed decisions will result. Biologic age will be multifactorial, involving cognitive, emotional, physical, and nutritional attributes as well as specific organ function (lung, kidney, liver) because no single feature can characterize the total elderly patient. The concept of competing risks among the cardiovascular disease being treated, comorbidity, risks of study, and life expectancy will evolve because even the most successful therapy will have limited effect on longevity in the very old. Although important research at the cellular and molecular level will characterize and provide better understanding of the aging process, it is not likely that this basic information will be immediately useful in the management of the large number of elderly patients with major cardiovascular disease. Preventive measures, including physical exercise, mental stimulation, avoidance of depression, good nutrition, and abstinence from tobacco use, are useful approaches to postpone or ameliorate the consequences of aging and allow patients to tolerate cardiovascular diseases better when they become manifest.

Therapy for acute myocardial infarction in older persons

OBJECTIVE

To review the early management of acute myocardial infarction (AMI) in older adults.

METHODS

Recently published studies relevant to the early management of AMI were systematically reviewed. When possible, the impact of older age on complication rates and clinical outcomes was evaluated.

RESULTS

In general, AMI therapies that are effective in younger patients are also effective in older patients. Conversely, older age is associated with an increased risk of complications from therapy, implying that careful patient selection is required to optimize outcomes while minimizing risks. The principal limitation of currently available data is that relatively few patients older than the age of 80 have been enrolled in prospective randomized clinical trials.

CONCLUSIONS

Thrombolysis and primary angioplasty are effective in establishing reperfusion and improving clinical outcomes in older patients with AMI. In the absence of contraindications, aspirin and beta blockers should be considered standard therapy in AMI patients of all ages, whereas heparin, nitrates, and angiotensin converting enzyme inhibitors are indicated in selected subgroups. At the present time, calcium channel blockers, magnesium, and antiarrhythmic agents are not recommended for routine use in the AMI setting, and the role of glycoprotein IIb/IIIa inhibitors, low molecular weight heparin, and other newer agents await the results of ongoing clinical trials.