The Prevention of Cardiovascular Disease in Older Adults

Patrick P. Coll, MD, AGSF; Vivyenne Roche, MD, AGSF; Jaclyn S. Olsen, DO; Jessica H. Voit, MD; Emily Bowen, MD; Manish Kumar, MD

Disclosures

J Am Geriatr Soc. 2020;68(5):1098-1106. 

In This Article

Stroke

Epidemiology of Stroke in Older Adults

The brain is acutely sensitive to oxygen deprivation. Acute oxygen deprivation of the brain can result in either a transient ischemic attack (TIA) or a stroke. Stroke is a common cause of hospitalization, disability, and death for older adults.[6,7] Stroke is the fourth leading cause of death in the United States (US), with the number of incident strokes projected to more than double in the coming years, especially among persons aged 75 years or older.[8–10] Cerebrovascular disease is also a risk factor for dementia.[11]

Preventing a First Stroke in Older Adults

Hypertension. Hypertension is the most important modifiable stroke risk factor. Though it was once thought that older patients needed a high blood pressure (BP) to maintain good cerebral blood flow, important epidemiologic data, including data from the Framingham Study, dispelled this misunderstanding by showing that the risk of stroke increased with increasing BP, especially in older adults.[12] We now know from observational studies that age-specific mortality rates from stroke, including those older than 80 years, continue steeply down at least as far as a usual systolic BP (SBP) of 115 mm Hg.[13] Depending on the threshold used, elevated BP is present in greater than 50% of patient deaths due to stroke or CVD and 25% of cardiovascular events.[14,15] There is also strong evidence that lowering BP in hypertensive patients reduces stroke risk.[16] It is still not clear what the ideal BP is for older adults over the age of 75 years.[17]

The first large-scale trial to demonstrate the stroke-reducing benefits of lowering SBP in older adults was the Systolic Hypertension in the Elderly Program (SHEP).[18] The goal SBP in SHEP was lower than 160 mm Hg, and the mean age was 72 years. The trial was stopped early because of a significant reduction in the incidence of stroke (36%) in the intervention group. The Treatment of Hypertension in Patients 80 Years of Age and Older (HYVET) study was designed to study the impact of BP reduction in patients who were older than those enrolled in SHEP.[19] The mean age of patients in HYVET was almost 84 years. The goal BP was 150/80 mm Hg. In an intention-to-treat analysis, over approximately 2 years, active treatment was associated with a 30% reduction in the rate of fatal or nonfatal stroke. The 2015 Systolic Blood Pressure Intervention Trial (SPRINT) sought to assess whether intensive (<120 mm Hg) or standard (<140 mm Hg) SBP control in adults at increased risk for CVD, without diabetes, reduced CVD morbidity and mortality.[20] Though there was an overall significant reduction in CVD events in the intervention group, the intensive BP target group did not demonstrate a significant reduction in the incidence of stroke. A subset analysis of SPRINT data for ambulatory persons aged 75 years or older demonstrated decreased rates of fatal and nonfatal CVD events and death from any cause, but once again there was not a significant reduction in stroke incidence.[21] The mean age of this subgroup was almost 80 years. Even though these older adults in SPRINT did not have a statistically significant reduction in stroke, they did experience a significant reduction in overall CVD events, and this improvement in outcomes was greater for those older than 75 years than those who were younger. Good BP control reduces stroke risk for older adults (Table 1).

Lifestyle Modification. Smoking tobacco is a significant risk factor for stroke.[62] Cigarette smokers have been estimated to have a fourfold increase in stroke risk related to smoking alone.[63] Despite increased knowledge about the negative impact of smoking on health, large numbers of Americans continue to smoke. Those aged 65 years or older comprised 8.2% of smokers.[64] Rates of tobacco smoking are even higher in middle- and low-income countries. According to the World Health Federation, four countries (China, India, Russia, and Indonesia) account for more than 50% of ischemic stroke deaths related to smoking tobacco.[65] Due in part to the fact that fewer smokers live into old age, most of the data pertaining to the risk of stroke from smoking tobacco and the reduction in risk from cessation, are for younger smokers. Though not specific to older adults, the benefits of quitting smoking, including reduced stroke risk, have been clearly demonstrated in large-scale long-term epidemiological studies.[22] All patients who smoke cigarettes or use other forms of tobacco, regardless of age, should be advised at every medical visit to quit. Healthcare providers should guide, support, and provide treatment for patients who try to stop using tobacco products.

There is limited evidence that adherence to a Mediterranean diet reduces stroke risk.[52] Though not specific to stroke reduction, and not specific for older adults, the American Heart Association (AHA) recommends consuming a "colorful diet" rich in vegetables, fruits, legumes, nuts, whole grains, and fish. Foods with high saturated fat should be limited to 5% of daily recommended calories.[23]

While controlling for other risk factors, regular physical activity in a study population in the US with a mean age of 70 years was associated with a significant reduction in stroke incidence.[24] This study also demonstrated a dose-response relationship for both exercise intensity and duration. Other studies have demonstrated similar benefits.[25]

Lipid-lowering Agents. Though there is no evidence that lipid-lowering agents help prevent incident stroke in older adults,[66] as discussed in the section below on preventing CAD, there are data that support the use of statins to prevent composite CVD outcomes in older adults who do not have a history of CVD, up to 80 years of age.

Antiplatelet Therapy. Antiplatelet therapy is not recommended to prevent a first stroke in older adults. The Effect of Aspirin on Cardiovascular Events and Bleeding in the Healthy Elderly trial showed a significantly higher risk of major hemorrhage for older patients (median age = 74 years) who were given a daily dose of 100 mg of enteric coated aspirin, which did not result in a significantly lower risk of CVD, including stroke, than placebo.[27]

Anticoagulation for Atrial Fibrillation. Atrial fibrillation (AF) is a risk factor for stroke. AF is common in older adults, and the prevalence of AF increases with increasing age.[67] There is extensive evidence that anticoagulation reduces stroke risk for most patients with AF.[28] The CHA2DS2-VASC score can help clinicians decide which patients will benefit from anticoagulation. Age is a component of a CHA2DS2-VASC score. Patients younger than 65 years are scored 0, those aged 65 to 74 years are scored 1, and those 75 years or older are scored 2. Using CHA2DS2-VASC, men with a score of 2 or greater and women with a score of 3 or greater should undergo anticoagulation.

Though establishing stroke risk in older patients with AF is important, it is also important to consider both the type and dose of anticoagulant medication to use and to consider contraindications to anticoagulation. Antiplatelet medications, such as aspirin and clopidogrel, do not provide adequate protection against stroke in patients with AF. Though warfarin was widely used at one time, its use for this indication has dropped precipitously since the introduction of novel oral anticoagulants (NOACs). NOACs are as effective as and safer than warfarin with regard to stroke prevention and major bleeding complications.[68] Subgroup analyses have confirmed similar outcomes in both older and younger adults with AF.[69,70]

Many older adults with AF who should be anticoagulated are not. Though there may be circumstances where anticoagulation should not be used or should be discontinued, these circumstances are uncommon. Anticoagulation for older adults is often discontinued when a patient has had a fall or is deemed to be a high fall risk. There may be a concern that older patients on oral anticoagulants who fall are at high risk for an intracranial hemorrhage (ICH). A subanalysis of the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation trial demonstrated that most ICH events were spontaneous rather than traumatic.[71] For older adults with AF, including those at risk for falling, the risk benefit calculation generally favors anticoagulation.[72] Shared decision making is an appropriate approach for these patients. Bleeding risk can be assessed by several scoring systems, including HAS-BLED, HEMORR2HAGES, and ATRIA.

Screening for Carotid Artery Stenosis in Older Adults

Carotid artery stenosis (CAS) is a risk factor for stroke. However, screening for CAS in asymptomatic adults, including older adults, is not recommended.[29] Screening for carotid disease may be considered for those diagnosed with CAD and PAD, especially if these patients are being considered for revascularization procedures. Screening for asymptomatic CAS should be considered in those undergoing coronary artery bypass grafting (CABG) who are at high risk for perioperative stroke. Based on current guidelines, a carotid vascular intervention can benefit a select subset of older adults with asymptomatic severe CAS who have a life expectance of greater than 5 years, favorable anatomy, and high risk of stroke.[30]

Preventing a Subsequent Stroke in Older Adults

Hypertension. BP control remains important for reducing the risk of a subsequent stroke. Guidelines from the AHA and the American Stroke Association recommend a goal SBP of lower than 140 mm Hg and a diastolic BP of lower than 90 mm Hg for those who have had a stroke or TIA, without addressing age.[31]

Lifestyle Modification. There is strong evidence that smokers who experience a stroke can substantially reduce their risk of a subsequent stroke by stopping smoking.[32] Though these data do not pertain specifically to older adults, it is advisable to recommend that older adults who have had a stroke and continue to smoke cigarettes should stop.

There is little evidence that diet alone or exercise alone has an impact on the incidence of a subsequent stroke.[73] However, exercise and diet as a component of a lifestyle modification program for adults with a mean age of 60 years, who had a recent TIA or stroke, did demonstrate a reduced risk of a subsequent stroke.[33]

Lipid-lowering Agents. There is strong evidence that patients who have had a stroke or a TIA benefit from the use of lipid-lowering agents to reduce the risk of a future stroke.[34] Older adults with a history of stoke or TIA also benefit from the use of lipid-lowering agents.[35,36]

Antiplatelet Therapy. Patients who have had a stroke or a TIA benefit from the use of antiplatelet agents to reduce the risk of a subsequent stroke.[37] There are, however, few data regarding patients older than 75 years.

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