Hypertension in the Elderly-Management

Hypertension in the Elderly-Management

Introduction

As more of us are getting older and older, we are facing the risks associated with hypertension. By 2025, it is estimated that 20% of the U.S. population will be older than 65 years. The subgroup of people older than 80 years is one of the fastest growing segments of the population. It is now recognized that hypertension, especially isolated systolic hypertension, is indeed connected to age. Up to 50% of people ages 60 to 69 years have hypertension, but nearly 75% of those older than 70 years have some degree of hypertension. More startling is the finding that the risk for developing hypertension if one lives to the age of 85 years is 80% to 90%. In older patients, it is clear that the systolic blood pressure is a more important predictor of future cardiovascular events than the diastolic blood pressure. And the risk for developing hypertension and future cardiovascular disease is also increased in those with blood pressures in the range of 120 to 139 mm Hg, levels previously considered normal. Multiple trials have demonstrated a reduction in mortality, cardiovascular mortality, stroke, and congestive heart failure with treatment. Despite this, systolic hypertension in elderly people is often inadequately treated. There are multiple reasons for this: reaching goal blood pressure usually requires multiple medications; patients and physicians may have negative attitudes regarding treatment in this age group; and older patients may have more complications with orthostasis and other side effects.

Etiology and Pathogenesis

Most cases of combined systolic and diastolic hypertension occur by the age of 55 years. Systolic hypertension, defined as a systolic blood pressure of more than 140 mm Hg with a diastolic blood pressure of less than 90 mm Hg, is principally associated with aging. Other differences seen in elderly people include lower renin levels, higher sensitivity to sodium loads, and increased peripheral vascular resistance.

Clinical Presentation

Most patients do not have symptoms, which contributes to the lack of recognition of this problem and the associated public health epidemic. Patients may present with symptoms of cardiovascular disease, heart failure, stroke, or renal failure. The physical exam may reveal evidence of left

ventricular hypertrophy, indicating an increased risk for cardiovascular disease .

Differential Diagnosis

Pseudohypertension, falsely high sphygmomanometer readings secondary to decreased arterial wall compliance and increased vascular stiffness, should be considered in older persons with persistently elevated blood pressure measurements, no evidence of end-organ damage, near-syncopal symptoms with therapy, or a discrepancy in blood pressure readings between arms. White-coat hypertension, with blood pressure readings taken during clinic visits that greatly exceed those taken at home or after the patient has had time to relax, is more commonly seen in older patients. The noncompliant vascular

tree probably makes elders more susceptible to labile blood pressure swings. Ambulatory blood pressure monitoring can be helpful to identify this and is reimbursed by Medicare. In addition to identifying lower blood pressures that may correlate better with future cardiovascular events than clinic readings, the lack of a decrease in blood pressure at night may identify patients who are particularly high risk for future cardiovascular events. Secondary causes of hypertension are far less common in older patients, and further evaluation is indicated only with documented new onset and pronounced hypertension or new difficulty in controlling blood pressure. Renal artery stenosis is the most common secondary cause of elevated blood pressures in this age group . The challenge is that many patients in this age group also have underlying diffuse small vessel disease because of atherosclerosis, and any correction of stenosis at the level of the renal artery does not necessarily correct the underlying renovascular compromise.

Diagnostic Approach

The diagnosis of hypertension is based on the classification system used by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure for all adults (systolic blood pressure greater than 140 mm Hg or diastolic blood pressure greater than 90 mm Hg). Systolic hypertension, previously known as isolated systolic hypertension, is defined as a systolic blood pressure of more than 140 mm Hg with a diastolic blood pressure of less than 90 mm Hg. Hypertension is diagnosed based on two or more readings with an appropriately sized cuff, after the person has been sitting for 3 minutes. Because blood pressure variability is more common in elderly people, multiple readings are of great importance. Postural hypotension is common in elderly people; so, before initiating or altering treatment, blood pressure should be measured after the patient has been standing for 3 minutes.

Management and Therapy

Why Treat?

There is strong evidence that pharmacologic treatment of systolic hypertension in older patients reduces cardiovascular events, including strokes and heart failure. Studies have consistently demonstrated a 35% reduction in stroke, 50% reduction in congestive heart failure, and 30% reduction in overall cardiovascular events in older patients who are treated. One meta-analysis examining the risks and benefits of treatment for isolated systolic hypertension in elderly people found that treatment decreased total mortality by 13%, cardiovascular mortality by 18%, all cardiovascular complications by 26%, and stroke by 30%. Greater benefits were seen in men, patients older than 70 years, and patients with prior cardiovascular complications. Notably, benefits are seen in the oldest patients, those older than 80 years, with 22% reductions in cardiovascular events and 39% reductions in heart failure. Whether treatment in very elderly patients improves mortality is less clear; however, there is significant benefit in improved in this age group.

Optimum Treatment

Treatment guidelines for older and younger patients are similar. Thiazide-type diuretics should be considered first line—these are the agents that were used in the major trials for the treatment of systolic hypertension in elderly patients. In addition, these agents are inexpensive, are usually well tolerated, and recently were demonstrated to be of equal or better effectiveness in reducing future cardiovascular events. Most older patients with systolic hypertension require more than one drug—many will need three medications to reach goal blood pressure. Other agents such as ß-blockers, angiotensin-converting enzyme inhibitors, and calcium channel blockers are also effective and should be added depending on specific patient comorbidities like congestive heart failure.