March/April 2015

Treating Hypertension
By Mark D. Coggins, PharmD, CGP, FASCP
Today's Geriatric Medicine
Vol. 8 No. 2 P. 6

Measured in mm Hg, blood pressure (BP) is reported in terms of systolic BP (SBP) over diastolic BP (DBP). For example, normal BP may be read as 120 over 80 mm Hg or written as 120/80 mm Hg. SBP is the force blood exerts on the artery walls when the heart contracts to pump blood out (pressure in the arteries when the heart is beating). DBP measures the force as the heart relaxes to allow the blood to flow into the heart (pressure in arteries while the heart rests between heartbeats). The difference between the systolic and diastolic readings is known as the pulse pressure and is an indicator of the stiffness and inflammation in blood vessel walls. A high pulse pressure in older adults is a strong indicator of heart problems.1

Changes With Age
Age-related arterial stiffness impairs the aorta's ability to accommodate blood expelled during systole and recoil during diastole. As a result, DBP typically levels off or decreases with increased age, while SBP continues to increase as does pulse pressure (SBP minus DBP).2 By the age of 70, more than 90% of hypertensive patients have isolated systolic hypertension while isolated diastolic hypertension occurs in less than 10% of hypertensive patients. After the age of 50, SBP becomes a more important cardiovascular risk factor than DBP and is the primary focus of hypertension treatment in the older adult.3

Importance of Proper BP Technique
Accurate BP measurement is essential to appropriately identify and manage hypertension. Improper BP technique can lead to inaccurate BP measurement with even small discrepancies of +/- 5 to 10 mm Hg in BP measurement having considerable negative consequence. Measurements reported inaccurately low by 5 mm Hg would label more than 20 million Americans with prehypertension when true hypertension is present. The resulting potential consequence could be a 25% increase over current levels of fatal strokes and fatal myocardial infarctions due to inadequate treatment. An overestimate of true BP by 5 mm Hg would lead to nearly 30 million Americans potentially receiving antihypertensive medications that could lead to associated side effects, psychological effects of misdiagnosis, and unnecessary cost. Health care professionals are encouraged to review and employ best practice steps for taking BP. Factors potentially affecting the accuracy of BP measurements are noted in Table 1.4

Hypertension Treatment Guidelines
The clinical benefits of treating hypertension are well established and include reductions in stroke, myocardial infarction, heart failure, kidney failure, and overall cardiovascular disease (CVD) morbidity. However, defining a goal target BP for older adults is a matter of debate and varies among hypertension treatment guidelines (See Table 2). Regardless of the guideline used, nonpharmacologic interventions such as weight loss, diet, exercise, and review of medications that may increase BP should be considered. If patients subsequently remain hypertensive, drug therapy should be considered.

Eighth Joint National Committee (JNC-8) Guidelines5
The 2014 JNC-8 guidelines have created controversy around increased target BP goals in older patients. While the new JNC-8 guidelines continue to recommend a target BP of <140/90 for younger patients, the recommended target BP for patients aged 60 years or older has been loosened with the goal BP increased to <150/90 or <140/90 for those older adults with diabetes or kidney disease.

The JNC-8 recommendations to treat high BP to a goal of <150/90 in the general population aged 60 or older was unanimously voted upon by the panel and is clearly supported by moderate to high quality evidence from randomized controlled trials that demonstrate reductions in stroke, heart failure, and coronary heart disease. However, the increased target goal to <150/90 in patients over the age of 60 is based on lower quality evidence from two studies. These studies suggest that a target SBP goal of <140 mm Hg in this age group provides no additional benefit. BP targets from these studies were 140 to 160 mm Hg in one study and 140 to 149 mm Hg in the other.

Several members of the JNC-8 panel recommended continuing the JNC-7 SBP goal of <140 mm Hg for individuals over the age of 60 based on expert opinion. These members concluded that the evidence was insufficient to raise the SBP target from <140 to <150 mm Hg in high-risk groups, such as black persons, those with CVD including stroke, and those with multiple risk factors. The panel agreed that more research is needed to identify optimal goals of SBP for patients with high BP.

Although the recommendation to increase the target BP to <150/90 was approved, the panel included a corollary recommendation based on expert opinion that treatment for hypertension does not need to be adjusted if treatment results in SBP <140 mm Hg without associated adverse effects on health or quality of life.

Benefits and Cost Effectiveness of JNC-8
A new study funded by the National Heart, Lung, and Blood Institute and others and published January 29 in the New England Journal of Medicine concludes that full implementation of the JNC-8 guidelines (goal BP <150/90 mm Hg in patients over the age of 60 and <140/90 mm Hg for all others) could help prevent approximately 56,000 cardiovascular events and 13,000 deaths from cardiovascular causes each year in the United States without increasing costs to the health care system.

Researchers used a Cardiovascular Disease Policy Model to simulate drug treatment and monitoring costs, costs averted for the treatment of CVD, and quality-adjusted life years gained by treating previously untreated adults from 2014 through 2024. The largest benefit would be observed among the 8.6 million American adults between the ages of 35 and 74 with hypertension but without CVD who are not currently being treated (primary prevention). For these patients, treating to the BP targets would prevent approximately 41,000 cardiovascular events and 7,000 deaths from cardiovascular causes each year. The study also reported that approximately 860,000 men and women with existing CVD and untreated hypertension (secondary prevention) would be eligible for antihypertensive medications every year with treatment preventing approximately 16,000 cardiovascular events and 6,000 deaths from cardiovascular causes.6

Individualizing BP Treatment
Most experts agree that antihypertensive side effects need to be considered when setting BP goals in the elderly. Poorly controlled BP can increase the risk for stroke and heart complications. However, BP medications and excessive lowering of BP can increase the risk of falls and cause other side effects. Patients should be monitored closely for orthostatic symptoms and other nonspecific symptoms such as weakness, failure to thrive, and cognitive complaints that may be related to low BP levels. Lying and standing BP should be obtained periodically in all hypertensive individuals over the age of 50. Orthostatic hypotension is a common barrier to intensive BP control that should be clearly documented; if present, drug therapy should be adjusted accordingly and appropriate warnings given to patients and/or caregivers.

Hypertension treatment should be individualized regardless of the treatment guideline being used. The advantages and disadvantages of aggressively treating BP need to be carefully considered for each patient. Practitioners concerned about not treating patients whose BP exceeds 140/90 due to fear of increased cardiovascular events may choose to follow stricter American College of Cardiology/American Heart Association recommendations which at this time continue to recommend a treatment goal of <140/90.

It is well established that lowering SBP reduces stress on the heart and provides significant benefit. However, excessively lowering BP, especially in an older adult, is also of concern. Treatment of patients over the age of 80 is especially complex, and overly aggressive treatment of BP may even reduce survival in these individuals.7

For the older adult, lowering BP to <120/80 is not recommended because of reduced tissue perfusion and the significant risk of side effects. Older adults, especially those over the age of 80, should always be checked for excessive orthostatic decline, and SBP <130 and DBP <65 should be avoided. In the Systolic Hypertension in Elderly Study, investigators concluded that lower DBP is of less concern for patients without CAD. However, for those patients with CAD, intensive antihypertensive therapy increases the risk of cardiovascular events when DBP is lowered to <60 mm Hg. These data were further validated in a later follow-up analysis of the Systolic Hypertension in Elderly Study, with an increase in cardiovascular events seen when treated DBP reached 70 m Hg with an even greater risk of CVE at 60 mm Hg. In another study (INVEST), the risk of cardiovascular events increased at a DBP between 60 mm Hg and 70 mm Hg.8 Additionally, elderly patients with diabetes treated to a DBP <65 mm Hg experienced an increase in mortality.3

A recent systematic review of studies published in December 2014 evaluated the benefits and harms of antihypertensive agents in adults aged 65 and older. Seven studies examined optimal BP targets. The review noted that strict control (SBP <140 mm Hg) was not consistently better than mild control (SBP <150 mm Hg) for adults aged 65 and older. Mild SBP control benefitted subjects in all age ranges over the age of 65. Older adults with hypertension had decreased cardiovascular morbidity and mortality with antihypertensives compared with no treatment. However, strict control was not consistently better than mild control in older adults.9

Tremendous evidence exists that antihypertensive treatment in the elderly patient is effective in reducing BP, total mortality, and cardiovascular events. Improving the treatment of hypertension in older adults should be implemented early and at a level sufficient to meet target BP goals, with medications adjusted to minimize excessive lowering of BP. This approach can help improve patient compliance while minimizing associated risks.

— Mark D. Coggins, PharmD, CGP, FASCP, is senior director of pharmacy services for skilled nursing centers operated by Diversicare in eight states, and is a director on the board of the American Society of Consultant Pharmacists. He was nationally recognized by the Commission for Certification in Geriatric Pharmacy with the 2010 Excellence in Geriatric Pharmacy Practice Award.

References
1. High blood pressure. Penn State Milton S. Hersey Medical Center website. http://pennstatehershey.adam.com/content.aspx?productId=10&pid=10&gid=000014. Updated June 30, 2014. Accessed January 12, 2015.

2. Pannarale G. Optimal drug treatment of systolic hypertension in the elderly. Drugs Aging. 2008;25(1):1-8.

3. Aronow WS, Fleg JL, Pepine CJ, et al. ACCF/AHA 2011 expert consensus document on hypertension in the elderly: a report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus documents developed in collaboration with the American Academy of Neurology, American Geriatrics Society, American Society for Preventive Cardiology, American Society of Hypertension, American Society of Nephrology, Association of Black Cardiologists, and European Society of Hypertension. J Am Coll Cardiol. 2011;57(20):2037-2114.

4. Handler J. The importance of accurate blood pressure measurement. Perm J. 2009;13(3):51-54.

5. James PA, Oparil S, Carter BL, et al. 2014 evidence-based guideline for the management of high blood pressure in adults: report from the panel members appointed to the Eighth Joint National Committee (JNC 8). JAMA. 2014;311(5):507-520.

6. Moran AE, Odden MC, Thanataveerat A, et al. Cost-effectiveness of hypertension therapy according to 2014 guidelines. N Engl J Med. 2015;372(5):447-455.

7. Oates DJ, Berlowitz DR, Glickman ME, Silliman RA, Borzecki AM. Blood pressure and survival in the oldest old. J Am Geriatr Soc. 2007;55(3):383-388.

8. Messerli FH, Panjrath GS. The J-curve between blood pressure and coronary artery disease or essential hypertension: exactly how essential? J Am Coll Cardiol. 2009;54(20):1827-1834.

9. Goeres LM, Williams CD, Eckstrom E, Lee DS. Pharmacotherapy for hypertension in older adults: a systematic review. Drugs Aging. 2014;31(12):897-910.