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CARDIOLOGY CASEBOOK |
Over 50 million Americans have elevated blood pressure. The prevalence of hypertension increases with age and is greater in blacks and in lower socioeconomic groups. Costs of detection and drug therapy are estimated to exceed $9 billion annually. The prevalence of essential hypertension in the elderly (above age 65) exceeds 50%. Treatment generally is more difficult in the elderly. Since hypertension is so common in the elderly and is associated with greater complications than in younger hypertensives, the benefits of lowering blood pressure (BP) are substantial.
QUESTIONS
-blocker ANSWERS
1. a. systolic <140, diastolic <90
Hypertension repeatedly has been shown to be a significant risk factor and plays a key role in 35% of all atherosclerotic events. Hypertension has been implicated in major cardiovascular, cerebrovascular, and peripheral vascular disease. Population-based studies confirm that hypertension increases the risk of an atherosclerotic event 2–3 fold when compared with normotensive. Although hypertension is one of many cardiovascular risk factors (Table 1
), prognosis depends more on the sum of the risk factors than on absolute BP values. Many of the consequences of hypertension can be partially reversed with BP control.1
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160 and diastolic hypertension as 
90 mmHg. In the United States, the former criteria prevail and should be adhered to (Table 2).
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Increases in longevity in the western industrialized societies have been associated with an increased prevalence of hypertension, coronary and cerebral atherosclerotic vascular disease, type II diabetes mellitus, and renal disease. The high incidence of these chronic diseases is due, in part, to obesity, sedentary lifestyles, use of nonsteroidal anti-inflammatory medications, and environmental factors. In the United States, the incidence of systolic hypertension increases with age in both genders, reaching 50% in those older than age 65. In some surveys, as many as 75% of persons 75 years and older have ISH. In the middle-and older-age groups, the systolic BP is a stronger predictor of risk than the diastolic BP.
2. d. all equal in frequency
In the elderly, BP must be measured with special care to avoid misdiagnosis. Pseudohypertension (falsely high readings) is common in elderly who have decreased vascular compliance. Palpation of the pulse while auscultating BP sounds is suggested when BP sounds are not distinctly heard; however, errors in BP may be as high as 20 mmHg, which obviates this method of BP measurement. White-coat hypertension (apprehension when an office-based practitioner records the BP) is common in older persons, especially in women. These excessive variations in systolic BP suggest anxiety-induced fluctuations. BP readings taken outside the office setting may help reveal hypertension. Since the elderly are more prone to orthostatic falls in BP, measurements should be taken in the standing and sitting positions and preferably following 10–15 minutes of rest. Auscultatory gaps can occur during cuff deflation. This is a result of the loss and reappearance of Korotkoff’s sounds between systolic and diastolic pressures in the absence of cardiac arrhythmias. Suspiciously high or low systolic pressures may be registered. This will certainly pose a problem for automatic recordings. The presence of auscultatory gaps is clinically significant because it is associated with an increased presence of target organ damage.
The majority of elderly have ISH; however, it is more common in elderly women. The association of ISH with cardiovascular and cerebrovascular disease has been clearly established.3 Typical of ISH is a widened pulse pressure (PP), where wide fluctuations of pressure levels predispose the patient to a greater risk for atherosclerotic plaque rupture and subsequent cardiovascular events.3 Treatment of ISH must be approached with caution since pharmacotherapy, intended to reduce systolic BP, has the potential to reduce a concomitant normal diastolic BP below the critical limit for coronary artery perfusion. There has been concern that excessive BP reduction may increase mortality in the elderly by increasing the incidence of stroke and myocardial infarction. Although 80 mmHg or below is considered a reasonable therapeutic goal for diastolic hypertension in the general population, modulation of the diastolic BP in the elderly has somewhat different outcomes. In the older population, diastolic hypertension patterns follow a J-shaped curve: The risk of cardiovascular events declines as the diastolic BP drops from over 100 to 85 mmHg but then rises again as the BP continues to drop below 80 mmHg. Recent reports on intra-arterial ambulatory BP readings in the aged population confirmed the fact that a low diastolic BP was positively related to cardiovascular death. Coronary artery filling is dependent on diastolic perfusion pressure. In normal coronary arteries, reduction of diastolic BP triggers coronary artery dilation, which increases blood flow to compensate. Atherosclerotic arteries are noncompliant and fail to dilate in response to reduced diastolic BP. As a result, a reduction of diastolic pressure to <55–60 mmHg may lead to decreased coronary artery filling and potentiate acute coronary events, especially in patients with ischemia and/or left ventricular hypertrophy where coronary artery reserve is impaired.3,4 Elevated BP in the elderly—either combined systolic/diastolic or ISH—increases cardiovascular risk. In combined hypertension, cardiovascular risk increases as systolic BP climbs above 140 mmHg or if the diastolic pressure rises above 90 mmHg or falls below 65 mmHg following therapy.4
In most cases of combined hypertension in the elderly, treatment is a slow, painstaking process. Adequate treatment of hypertension requires a multi-pharmaceutical approach. Attempts to achieve a reduction in risks of cardiovascular events while avoiding the untoward effects from overtreatment may require, in some, a higher therapeutic systolic pressure endpoint, eg, 155 mmHg. In low-risk groups with combined hypertension, reduction of the BP to <140/90 mmHg is a reasonable BP goal. In the elderly, this may be technically difficult and achieving a drop of 20 mmHg or more in systolic BP, thus avoiding side effects, is reasonable. In high-risk groups, that is, patients with diabetes, renal insufficiency or atherosclerotic heart disease, the goal of therapy should be more aggressive and directed at lowering the systolic BP below 130/80 mmHg.4 The elderly hypertensive may require aggressive therapy. In the black population, 70% of the elderly are hypertensive and have a greater risk for complications; therefore, therapy should be aggressive and the aim should be a diastolic BP <80 mmHg compared with the usual target of <90. Type II diabetes is a known target for atherosclerotic disease. Patients with slow progressive renal failure (excreting more that 1–2 g protein/d) require BPs of less than 130/80 mmHg to slow the rate of renal impairment.
The use of home BP monitoring devices (automatic BP recording, central processing, electronic reporting to primary care practitioner) has helped control and reduce BP. Telecommunication allows fine-tuning of medication and stimulates patient-initiated lifestyle changes and greater adherence to prescribed medications.5
3. e. all of the above
Changes in the aging body lend themselves to the development of hypertension and can create challenges in treatment. Physiologic changes in the elder habitus often affect the dosing and choice of medication. Patients over 80 require frequent monitoring of renal function and comorbid factor status and frequent evaluation of BP: As mentioned earlier, BPs are checked in the standing as well as sitting positions to expose symptomatic postural hypotension. Changes associated with aging that lead to hypertension are alterations in vascular compliance and insulin resistance. Other contributing changes include reduced cardiac output, left ventricular hypertrophy, reduced renal function, increased salt sensitivity, reduction of total body mass, and decreased baroreceptor sensitivity. The same aging physiology also heightens the sensitivity to therapeutic interventions. The ability to swallow pills and pay for prescribed medication can also affect the outcome of therapy.
Loss of Arterial Compliance
Inherent to the aging process, the systolic BP continues to rise while diastolic BP plateaus and then decreases after 50 years of age. In the older population, systolic BP is a better predictor of event risk (coronary artery disease, congestive heart failure, end-stage renal disease, stroke) than diastolic BP. Increased systolic BP reflects the various alterations that occur within the vascular wall, eg, increased collagen and calcium, decreased elastin and magnesium content, and elastin fracture. The vessels become more rigid and less responsive to vasodilation. Stiffening of the blood vessels can also lead to unequal changes in systolic and diastolic pressures. PP, the difference between systolic BP and diastolic BP, implies reduced vascular compliance in the large arteries. Elevated PP, ie, 60–70 mmHg, is considered by some to be a better marker of cardiovascular risk than the systolic or diastolic BP. The stiffer the arterial vessels, the greater the difference in systolic and diastolic BP. Arterial stiffness increases vascular impedance and raises the systolic BP. The lower diastolic BP reflects a smaller blood volume within large, rigid, atherosclerotic vessels during diastole. Widened PP is common in the elderly, who tend to have ISH. Currently, the systolic BP is considered reasonable and less complicated than measuring PP. Repeated studies have shown that systolic BPs are accurate predictors of outcome.
The physical examination of the elder patient may reveal carotid or abdominal bruits with varying implications. The presence of a carotid bruit with possible compromise of the cerebral circulation warrants gradual BP reduction. An abdominal bruit that is holosystolic and high pitched with an early diastolic component may suggest the presence of severe renal artery stenosis (fibro-muscular dysplasia) and warrants careful use of ACE inhibitors or ARBs, which may lead to reduction in renal function with BP lowering. Systolic abdominal bruits are not uncommon in the elderly and are typically short and coarse in comparison to aortic or renal artery bruits.
Insulin resistance often accompanies hypertension, especially in the elderly. Obesity (visceral/central type) is considered the link between hypertension and insulin resistance. Systemic hemodynamics are also altered in the obese. Renal function decreases in the elderly by age 70, and functioning nephrons are decreased by more than 50% despite a normal BP. Serum creatinine levels do not accurately reflect the degree of nephron loss; a 50% reduction in renal function may have normal levels of serum creatinine, and, as a result, clinical decisions and therapy can be affected. Hypertension hastens the rate of nephron loss and severity of established renal failure. When serum creatinine levels begin to rise, considerable glomerular damage has already occurred, and noncognizance of the renal status when treating hypertension may lead to fulminating renal failure. Renal artery stenosis is more common in the elderly and requires cautious use of ACE inhibitors (lower doses, slow titration). Decreased renal or hepatic function affects the excretion or metabolism of drugs, respectively.
Decrease in Baroreceptor Sensitivity
Impaired baroreflex function is reflected by the poor reflex ability to augment heart rate and cardiac output after standing up or after eating (postprandial hypotension). Postural hypotension is more common in the aged than in younger patients, but its presence should not preclude prudent antihypertensive therapy. BP should be routinely checked in the sitting as well as standing positions to rule out postural hypotension. Patients who complain of dizziness can have normal sitting BPs in the practitioner’s office.
Decrease in Cardiac Output
Reduction of BP and afterload with certain medications can increase cardiac output. Medications that vasodilate, such as -blockers, should be used with caution to avoid further reduction in cardiac output.
Reduction of Body Mass
Loss of muscle mass in the elderly requires that initial dose of medication be conservative. Anti-hypertensive medication should be started at the lowest dose, which may be half the normal starting dose.
Other factors that must be considered in the elderly are tablet size to be swallowed and expense of medication.
4. b.lifestyle modifications such as attaining normal weight, reducing sodium intake, and exercising regularly
e.2 drug combination, ie, a diuretic with a ß-blocker, ACE inhibitor, or an ARB
The elderly usually respond to the use of non-pharmacologic therapy (reduction in dietary salt, increased exercise, weight loss), which is recommended in the initial approach to BP therapy in low-risk groups. Pharmacotherapy will be required if BPs cannot be reduced to <140/90 mmHg. Pharmacotherapy, outlined by the Joint National Council on Hypertension-VI guidelines, is reserved for those in whom lifestyle changes have not been successful, as well as in those at any age with high BP >139 mmHg and if BPs are >129 mmHg in patients with comorbid factors, eg, diabetes mellitus, renal impairment, which places them at higher risk for cardiovascular events.
The recommendations of the Joint National Council on Hypertension-VI of 1997 for initial pharmacotherapy include a thiazide diuretic or a thiazide diuretic in combination with a ß-blocker or with an ACE inhibitor or ARB. The outcome of the WHO-International Society of Hypertension meeting in 1999 reported that it was the degree of BP reduction that led to changes in morbidity and mortality, and not the agent used. Accordingly, it was advised that any of the BP-lowering drugs (diuretics, ß-blockers, ACE inhibitors, calcium channel blockers [CCBs], ARBs) can be used.6 Several ensuing trials that compared and evaluated antihypertensive agents revealed the following: 1) diuretics and ß-blockers appear as effective as the newer agents; 2) diuretics reduce cardiovascular events to a greater degree than -blocking agents; 3) strokes were more common in those treated with ACE inhibitors than with ß-blockers; 4) in diabetics, those treated with ACE inhibitors had fewer myocardial infarctions and episodes of congestive heart failure than the CCB group; 5) there were fewer myocardial infarctions and reports of congestive heart failure in the diuretic-treated group; and 6) there were more reports of cardiovascular events in the CCB-treated group. The premise of combining more than one agent to treat hypertension is based upon the cumulative and characteristic effect of each agent on the various hypertensive pathways. Essential hypertension is the result of multiple mechanisms, which justify the use of combination therapy. Currently, it is recommended that initial therapy in the general hypertensive population begin with either a diuretic plus a ß-blocker or an ACE inhibitor plus a diuretic. All three are frequently used in combination, ie, diuretic, ß-blocker and ACE inhibitor. The ß-blockers and ACE inhibitors counteract diuretic-induced potassium loss. ACE inhibitors combined with CCBs have also been effective, tend to be well tolerated, and may reduce proteinuria; CCBs are currently not first line therapy.7 Single drug therapy (use of only one drug) is only 50% effective in reducing hypertension and is very rarely used in treating BP.
5. e.all of the above
Due to the reluctance on the part of many practitioners to treat hypertension in the elderly, less than 20% of persons over 80 are actually controlled.8–10 Many practitioners readily treat a diastolic BP of 95 to 100, but do not treat isolated elevations in systolic BP (150–160), which are more common in the elderly and carry the greatest cardiovascular risk. Part of this reluctance stems from early (1940s) beliefs that an elevated systolic BP was a natural response that guaranteed blood flow to the brain and kidneys. In the 1970s, recommendations for treating the elderly were reserved for those with systolic BP >200 mmHg or diastolic BP >120 mmHg, since it was thought that the elderly were intolerant to BP-lowering medications. The myth that hypertension is normal in persons over age 60 still prevails in some practices. Misinterpretation of data has lead many to believe there is still a lack of clinical evidence supporting the benefit of antihypertensive therapy in the elderly and to be fearful of inducing ischemic events by lowering the BP; others were concerned about side effects. In the trial data, most elderly patients who underwent cautious BP reduction had few side effects, and quality of life was not impaired. In some, cognitive function was improved; in others, there was a decrease in dementia. It is true, however, that because of comorbid conditions, the elderly may not tolerate medications as well as the young do.
6. b.always
A disparity still exists regarding the need or importance of treating the elderly hypertensive patient (>75 years of age) despite repeated randomized controlled trials that have shown that reductions in all major cardiovascular disease endpoints in elderly patients occur with BP control. Because hypertension is so common in the elderly and the risks of hypertension are greater than in younger people, the benefits of treatment are substantial. Preventing acute events reduces disability in this fragile group.8–10 Although treatment of hypertension in the elderly may not significantly prolong life, the risk reduction of acute cerebrovascular (hemorrhagic and nonhemorrhagic stroke) and cardiovascular events is significant. With adequate BP control, risk reduction and avoidance of untoward pharmacologic side effects (eg, postural hypotension and symptomatic bradycardia), treatment of elevated BP in the elderly, especially in those over the age of 80, has been clearly beneficial. In addition, well-controlled hypertension in the elderly can help in the prevention of dementia, diabetes mellitus type II, and syncopal falls due to postural hypotension.
7. a.cerebrovascular and coronary atherosclerosis
b.peripheral arteriosclerosis
c.congestive heart failure, abdominal aortic aneurysm
Cerebrovascular disease is an indication for anti-hypertensive therapy once the acute event has been stabilized. The goal is to slowly reduce BP while avoiding postural hypotension. Coronary artery disease, in conjunction with hypertension, places the patient at higher risk for cardiovascular morbidity and mortality. Therapy is aimed at gradual reduction of BP to avoid reflex tachycardia and sympathetic activation. In up to 30% of patients with hypertension, the left ventricle undergoes architectural remodeling (increase in left ventricular mass and size) in an attempt to normalize the wall stress effects of elevated arterial pressure (increased afterload pressure and elevated peripheral vascular resistance). Although left ventricular hypertrophy has been associated with a marked increase in morbidity and mortality (angina, myocardial infarction, sudden cardiac death, arrhythmia, stroke), left ventricular mass and wall thickness can be reduced by prolonged pharmacologic (afterload reduction) and nonpharmacologic interventions (sodium restriction, weight loss, exercise).11
Hypertension, left ventricular structural changes (either hypertrophic or dilation), and myocardial ischemia due to coronary artery disease can singularly, or in combination, lead to cardiac failure. Control of elevated arterial pressure improves myocardial function and prevents and/or reduces heart failure and cardiovascular mortality. Hypertension remains a major risk factor for developing carotid atherosclerosis, peripheral artery disease (claudication), and aneurysm. Other comorbid diseases frequently associated with hypertension and of equal significance include renovascular disease, diabetes mellitus, dyslipidemia, gout, bronchial asthma, or sleep apnea.
8. a.reduction in the majority of hypertensive patients
b.frequent and longer periods of exercise add to the benefits of exercise
c.facilitates regression of left ventricular hypertrophy
Low to moderate exercise training can lower the BP in the majority of hypertensives. Average systolic and diastolic BP reductions range from 11 to 8 mmHg, respectively. The more prolonged the training, the greater the reduction. There is a greater and more consistent reduction in diastolic BP in response to exercise training in the middle-aged (40–60) group when compared with the older and younger hypertensives. Regular exercise in women results in greater reductions in BP. Exercise training also reduces other cardiovascular risk factors by improving plasma lipoprotein levels and increasing insulin sensitivity. In preliminary reports, exercise training in hypertensives leads to regression of left ventricular hypertrophy.12
General Remarks Regarding Pharmacological Therapy in the Elderly Hypertensive Patient
Genetic differences among populations tend to have similar responses to medications, eg, black Americans and the elderly require high doses of ACE inhibitors. Combination therapy allows the use of multiple, low-dose medications to achieve BP goals, thus avoiding the side effects of high single-drug doses.
Diuretics are well tolerated and inexpensive and are the first line therapy in all hypertensives, including the elderly. In addition, diuretics can be effective in retarding osteoporosis in postmenopausal patients. The usual starting dose is 12.5 mg of a thiazide. An ACE inhibitor or a ß-blocker is frequently the second agent.9 Diuretics in high doses may cause postural hypotension and should be avoided.
ß-Blockers are beneficial and considered routine in the management of congestive heart failure, angina, and postmyocardial infarction.1 The combination of ß-blockers and a diuretic has been repeatedly shown to reduce morbidity and mortality in congestive heart failure and hypertension. In the elderly, ß-blocker therapy reduces strokes and heart failure postmyocardial infarction. The combination of a ß-blocker and a diuretic is considered first line therapy by the Joint National Council on Hypertension-VI. ACE inhibitors have proven to be effective in reducing morbidity and mortality in diabetics and in the elderly.
ARBs equate with ACE inhibitors in their function of reducing BP. ARB therapy has resulted in regression of proteinuria and decreases in left ventricular hypertrophy, as well as improvement in hemodynamics in congestive heart failure. Therapy with an ARB is considered when there are adverse reactions to an ACE inhibitor, especially in patients with ACE-induced cough. Because of the higher incidence of cardiovascular events associated with CCB therapy, they are not considered as primary therapy. CCBs can be effective in lowering BP when added to an existing therapeutic regimen. Only the nondihydropyridine CCBs (diltiazem, verapamil) have been shown to reduce the incidence of reinfarction in postmyocardial infarction patients. In contrast, ß-blockers have been much more effective in reducing morbidity/mortality and reinfarction. The use of CCBs combined with ß-blockers is cautioned due to the potential for bradycardias and negative dromotropic effects. Peripheral adrenergic blockers (-blockers) are primarily vasodilators and may provoke postural hypotension; -blockers are not used as primary therapy for BP. Hypertensives with prostatism are often on -blocker therapy because of their relaxing effects on the urethral sphincter.
Central 2-agonists decrease sympathetic outflow from the central nervous system. These agents (methyldopa, clonidine, guanabenz, guanfacine) reduce BP in 35–50% of patients. However, side effects occur in a high percentage of patients, and the drop-out rates are as high as 30%. Some of the adverse effects are dry mouth, headaches, depression, and fatigue.
Summary
The treatment of the elderly hypertensive patients has reduced the incidence of strokes, cardiovascular events, and cardiovascular morbidity. Regrettably, few hypertensive patients over 80 years of age are being treated, and those who are, are not being treated effectively. Hypertension, at any age, should be treated with a goal of BP <140/90 mmHg, as set by the Joint National Committee on Hypertension. This message should be spread throughout the medical community.
ACKNOWLEDGMENT
Supported in part by a grant from the Applebaum Foundation in loving memory of Joseph Applebaum.
Reprint requests: Louis Lemberg, M.D., University of Miami School of Medicine, Division of Cardiology (D-39), P.O. Box 016960, Miami, Fla 33101.
Miura K, Daviglus ML, Dyer AR, et al. Relationship of blood pressure to 25-year mortality due to coronary heart disease, cardiovascular diseases, and all causes in young adult men: the Chicago Heart Association Detection Project in Industry Study. Arch Intern Med. 2001;161:1501–1508.
Psaty BM, Furberg CD, Kuller LH, et al. Association between blood pressure level and the risk of myocardial infarction, stroke, and total mortality: the cardiovascular health study. Arch Intern Med. 2001;161:1183–1192.
This article has been cited by other articles:
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  K. B. Keller and L. Lemberg Secondary prevention of coronary artery disease in elderly persons: a treatise on a report by the american heart association. Am. J. Crit. Care., September 1, 2006; 15(5): 514 - 518. [Full Text] [PDF]
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