The Complex Challenge of Helping Older Adults Manage Cardiovascular Disease
This issue of the Journal of Cardiovascular Nursing is devoted to the particular issues that surround the treatment and management of cardiovascular disease in older adults. In the past, many cardiovascular research studies reported findings without regard to the differential effects of interventions in older and younger age groups. Today, with the increasing proportion of adults over age 65 in the US population, there is a growing interest in developing therapeutic approaches tailored to the needs of older adults. A variety of critical research questions must be answered, including the efficacy of cardiovascular risk factor modification in older adults, the psychosocial factors that affect self-management of heart disease, and the barriers to maintaining medication regimens or recognizing symptoms of acute events. The articles in this issue address some of these research questions and lay the groundwork for future studies that will discover the best approaches to treating cardiovascular disease in older adults.
An elderly population explosion is coming, beginning in 2010. By 2030, 1 in 5 US citizens will be over age 65 and 8.5 million Americans will be over age 85, double the number today. 1 The "oldest old" Americans-those aged 85 years or more-are the fastest growing group in the United States. This trend is important for future health care needs because individuals over age 85 are likely to have multiple chronic medical conditions, be disabled, use many medications, or need nursing care in hospitals or long-term care facilities.
The primary reason for the impending increase in the number of older adults in the population is the increase in life expectancy in the United States. Between 1900 and 2000, life expectancy in the United States increased from 51 to 80 years for women and from 48 to 74 years for men. 2 As Americans have increased their years of life, the prevalence of chronic conditions associated with age, including cardiovascular disease, has also increased. Currently, almost 18 million people in the United States have heart disease, more than half of them over age 65. In older adults, heart disease is a leading cause of death (38.2% of deaths in adults aged 85 or more), a major cause of disability (40% of adults aged 70+ with heart disease report disability compared to 26% of adults aged 70+ without heart disease), and a frequent reason for hospitalization (64.7% of patients discharged with a first diagnosis of cardiovascular disease were aged 65 or more). 3-5 The increasing number of older adults living many years with chronic cardiovascular illness requires us to develop strategies for treatment and management of cardiovascular disease that take into account the issues faced by older adults, who may have multiple coexisting medical and psychosocial conditions, environmental and personal barriers to managing symptoms and medications, and cognitive deficits that affect treatment and management.
The purpose of this issue of the journal is to explore some critical issues in providing care to elderly adults with cardiovascular disease. This introductory article will provide a brief overview of the physiological changes associated with aging that may predispose elders to cardiovascular disease and the challenges inherent in designing therapies appropriate to the needs of older patients. The articles that follow were selected to provide some understanding about the ways in which older adults differ from younger adults in their risk factors, perception of symptoms and health-seeking behaviors, adherence to treatment regimens, and the effect of cognition on self-management of heart failure.
Cardiovascular Changes Associated With Aging
Knowledge about what constitutes normal aging is still developing, but there is a growing recognition that many physiological changes in the cardiovascular system of older adults may be attributable to lifetime health behaviors, rather than to age per se. With increasing age, the entire cardiovascular system becomes stiffer. Arterial stiffness and loss of elastic recoil increase the mechanical burden on the heart as it works to move blood to the peripheral vasculature of the body. Systolic pressure increases secondary to the rigid arteries, and diastolic pressures fall as the arteries lack the elasticity to maintain intravascular pressures during diastole. 6,7
The greater workload of the heart eventually contributes to a loss of myocytes and a compensating enlargement of the remaining muscle cells. The lost cells may be replaced with connective tissue and collagen, further reducing the elasticity of the heart. In addition, calcium and amyloid deposition between cardiac cells occurs, resulting in impaired calcium usage and decreased energy turnover inside the cells, further decreasing the ability of the heart to relax.
It is not surprising that cardiac output, both at rest and with exercise, tends to decrease with advancing age, and maximal heart rate and ejection fraction attained with exercise are decreased. Older persons may have greater increases in systemic and pulmonary arterial pressures for a given increase in cardiac output, and the ability to handle increased venous return is diminished by reduced vascular and myocardial compliance.
Impaired relaxation (diastolic dysfunction) is the leading cause of heart failure in older persons, especially in women. The rate of diastolic filling declines with age, and at age 70, may be only half what it was at age 30. 6 The amount of oxygen and energy required for relaxation is actually greater than that required for contraction, and so impaired relaxation can potentiate myocardial ischemia. Impaired diastolic relaxation and filling decreases an older person's ability to tolerate a higher heart rate with its concomitant shortened diastole, and contributes to higher left ventricular diastolic pressures. Impaired diastolic filling causes the heart to be more dependent on atrial contraction, which may be responsible for over half of ventricular volume. Unfortunately, diastolic dysfunction may not be discovered until a person develops an extremely high heart rate during exertion or illness, or is diagnosed with atrial fibrillation.
Treatment of Cardiovascular Disease in Elders
Aggressive therapy for cardiovascular disease in adults over age 75 may be initiated less often because of beliefs about the patient not living long enough to reap much benefit. In addition, there is a lack of evidence-based knowledge about whether therapies pose risks that outweigh the potential benefits to older patients, some of whom have comorbid conditions and complicated medicated regimens. Societal pressures may also play a role in reducing aggressive therapy for cardiovascular conditions in elders. For example, a need to decrease health care costs may result in implicit or explicit rationing of health care.
Today, an increasing number of the oldest patients are undergoing revascularization procedures. Although mortality and morbidity are higher in this older population, most data indicate that coronary artery bypass graft surgery and percutaneous coronary interventions (PCI) outcomes have generally improved. 8,9 Survival after coronary artery bypass graft surgery in octogenarians has been shown to be 50% to 70% at 4 to 5 years, similar to that of the general population. 10 Data from a multiinstitutional database demonstrated an in-hospital mortality rate of 2.2% in octogenarians undergoing elective percutaneous coronary interventions, but in the setting of acute myocardial infarction the mortality rate was 14%. 9 One question that remains is how to select patients most likely to survive and benefit from revascularization procedures. Naturally, most studies of coronary procedures in octogenarians and nonogenarians are small, making it difficult to identify significant variables affecting outcomes. In addition, variables such as frailty that may have a significant impact on outcomes, are difficult to measure. 10 In older patients, more emphasis is on relief of symptoms and quality of life than on prolonging life.
Medication therapy is usually more difficult to manage in older patients with cardiovascular disease than in younger patients. Older adults are likely to have multiple coexisting conditions, many of which may affect the progression of cardiovascular disease. Control of hypertension, diabetes, and hypercholesterolemia is essential if cardiovascular disease is to be successfully treated. However, the medications and behavioral management of multiple chronic conditions may be difficult for older adults, especially those with cognitive difficulties or those without family members to help. Older persons with several chronic conditions may find it difficult to recognize symptoms and make self-care choices. Further, medications used to treat one condition may cause symptoms related to another condition, or increase the risk of adverse drug interactions. Grundy and colleagues 11 recommend that 2 factors be considered in selecting older patients for preventative therapy: overall prognosis and risk status. Patients expected to have relatively prolonged and healthy lives deserve attention to risk factors, and those with multisystem disease, debilitating conditions, marginal physiologic reserve, and limited life expectancy may be poor candidates for risk factor management.
The physiological factors suggested by Grundy et al 11 may not be a sufficient determinant of whether a patient will respond to therapy for cardiovascular disease. Older adults are also likely to have coexisting social, psychological, financial, and environmental conditions that contribute to complexity of care and affect their abilities to respond to therapy, manage symptoms, and prevent exacerbations of heart disease. Still, established therapeutic regimens to manage cardiovascular disease may be equally effective in younger and older adults if treatment, support, and follow-up are modified to ensure the best outcome for older patients. Many older adults have the potential to live 20 or more years with cardiovascular disease if they receive aggressive therapy to preserve cardiac function, and risk factor modification to prevent a subsequent event that might cause significant disability.
The Need for Cardiovascular Research That Includes Older Adults
Although the majority of patients with cardiovascular disease are older, many diagnostic and therapeutic methods have been tested in research studies using younger subjects. 7 The articles in this issue of the journal reflect a growing awareness of the need to conduct research studies to answer questions about the unique challenges faced by older adults with cardiovascular disease. These studies, and others like them, will lead the way for future research on potential therapeutic strategies to meet those challenges.
Two articles in this issue provide reviews of the present state of knowledge about physiological and psychosocial risk factors associated with cardiovascular disease in older adults. Fair discusses behavioral risk factors and comorbid conditions that predispose elders to developing cardiovascular disease, and whether therapeutic or behavioral modification of cardiovascular risk factors is effective in reducing morbidity and mortality in older persons. Stuart-Shor and colleagues present evidence for the importance of psychosocial factors, such as depression, anxiety, and social isolation, in developing the physiologic markers of cardiovascular disease. They suggest that an integrated intervention that incorporates behavioral and therapeutic strategies may be needed to manage cardiovascular disease in older adults, though more intervention studies are needed that include adults over age 70.
The article by Ryan and Zerwic addresses the important question of whether older adults are less likely than younger adults to recognize the symptoms of acute myocardial infarction. If symptoms are attributed to normal aging, or a comorbid condition, elders may delay seeking help. More research is needed in this area, according to the authors, because nursing interventions aimed at helping patients recognize symptoms may save lives.
Two descriptive studies of adherence behaviors in older adults are included in this issue of the journal. Evangelista and colleagues compared the compliance of older and younger adults with behavioral and medication regimens for heart failure. Older adults named barriers to compliance that may be amenable to nursing interventions, such as lack of energy, the presence of symptoms, and the difficulty of medication regimens. Dunbar-Jacobs and colleagues also report that more frequent daily medication dosage regimens were associated with poorer adherence in older adults with cardiovascular disease and comorbid conditions.
Finally, Bennett and Sauve present a thorough review of the literature to determine the current state of knowledge about the prevalence, severity, and type of cognitive impairment associated with heart failure in elderly persons. They conclude that prior studies are methodologically marred and future research must focus on longitudinal studies to identify the factors that link heart failure with cognitive impairment, so that interventions can be developed. Together, the articles in this issue serve as examples of research focused on the particular problems faced by older adults in managing chronic cardiovascular disease. As these and future studies identify factors that prevent older adults from recognizing symptoms, following treatment regimens, or making behavioral changes, nurses in clinical practice can design interventions tailored to the particular challenges faced by older adults in managing their cardiovascular disease.
REFERENCES