First-Line Therapy for Hypertension in the Elderly: Diuretics or Beta-Blockers?
First-Line Therapy for Hypertension in the Elderly: Diuretics or Beta-Blockers?
By Sally Beattie, MS, RN, CS, GNP
Summary-The recommendations for initiating hypertensive therapy in the elderly with uncomplicated essential hypertension have changed. Beta-blockers are no longer considered appropriate. Results of a recent meta-analysis demonstrated that compared with diuretics, beta-blockers do not confer acceptable outcomes related to cardiovascular morbidity, mortality, and all-cause mortality. The meta-analysis included 10 trials representing 16,164 patients, of whom 8217 received active treatment and were followed for an average of five years.
Two-thirds of patients assigned to diuretics were well-controlled on monotherapy, compared with less than one-third of those on beta-blockers. Diuretic therapy was superior to beta-blockade for all targeted outcomes. These findings are consistent with the revised recommendations of the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure.
A disturbing trend recently highlighted the need for appropriate and efficacious management of hypertension (HTN), especially for those over the age of 60. More than half of these individuals will develop some form of HTN during their lifetime. The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) indicated present rates of detection, treatment, and control of HTN have not improved, compared with the period between 1976-1991. Declines in stroke and coronary heart disease (CHD) have leveled off, but the incidence of end-stage renal disease and heart failure is increasing.1
The goal of anti-hypertension therapy is to reduce the incidence of cardiovascular (CV) morbidity and mortality. Numerous studies confirm the safety and efficacy of diuretics as monotherapy for all age groups; however, data on beta-blockers, which also have been recommended for use as initial monotherapy, are less clear. Researchers performed a meta-analysis to determine the efficacy of beta-blockers compared with diuretics. Their goal was to clarify indications for use of beta-blockers in elderly patients with essential, uncomplicated HTN.2
Beta-Blockers vs. Diuretics for HTN
Researchers evaluated beta-blockers' effect on blood pressure (BP), CV morbidity, mortality, and all-cause morbidity compared with diuretics in elderly patients with uncomplicated HTN. Articles published between January 1966 and January 1998 reporting randomized trials that lasted at least one year, used diuretics and/or beta-blockers as first-line agents, and addressed the relationship between HTN drug therapy, the elderly, and CV morbidity and mortality, were selected from a Medline search. Only trials that evaluated effects of drug treatment on morbidity or mortality in elderly persons (over age 60) with HTN were included in the analysis.
Outcome categories included coronary heart disease (CHD), cerebrovascular events, and cardiovascular mortality. (See Table 1.) The meta-analysis included 10 trials representing 16,164 patients, of whom 8217 received active treatment and were followed for an average of five years. Seven trials used diuretics, two used beta-blockers, and one had both a beta-blocker and diuretic treatment arm. The studies used eight drugs individually or in combination. (See Table 2.) Seven evaluated patients with diastolic HTN, two observed those with isolated systolic HTN, and one trial included patients with either systolic HTN or those with combined systolic and diastolic HTN.
Table 1
Categorization of Outcomes
Coronary Heart Disease |
o fatal and nonfatal myocardial infarction
o sudden or rapid cardiac death |
Cerebrovascular Events |
o fatal and nonfatal stroke
o transient ischemic attacks |
Cardiovascular Mortality |
o CHD and cerebrovascular mortality
o aneurysms o congestive heart failure |
Source: Messerli FH, Grossman E, Goldbourt V. Are B-blockers efficacious as first-line therapy for hypertension in the elderly? JAMA 1998;279:1903-1907.
Table 2
Drugs Used Across Studies in Meta-analysis
Thiazide | 2 studies |
Hydrochlorothiazide and triamterene | 1 study |
Hydrochlorothiazide and amiloride hydrochloride | 1 study |
Chlorthalidone | 3 studies |
Atenalol | 2 studies |
Atenalol, Pindolol, Metropolol | 1 study |
Source: Messerli FH, Grossman E, Goldbourt V. Are B-blockers efficacious as first-line therapy for hypertension in the elderly? JAMA 1998;279:1903-1907.
Beta-Blockers Found Less Effective
The researchers concluded that in contrast to diuretics, beta-blockers should no longer be considered as appropriate first-line therapy in this patient group. Two-thirds of patients assigned to diuretics were well-controlled on monotherapy, compared with less than one-third of those on beta-blockers.
Diuretic therapy was superior to beta-blockade for all targeted outcomes. In contrast to diuretic therapy, beta-blockade reduced the odds for cerebrovascular events but failed to favorably affect the other clinical end points. The investigators summarized why beta-blockers appear to be less effective in treating HTN in the elderly:
· comparatively weak anti-HTN efficacy;
· poor tolerance resulting in poor adherence;
· diminished efficacy of beta-adrenergic responsiveness;
· diminished exercise tolerance;
· adverse effects on preexisting co-morbid conditions;
· exposure of the older patient to a hemodynamic mismatch caused by beta-blockade manifested by a further decrease in cardiac output, systemic vascular resistance, renal blood flow, and glomerular filtration rate.
This hemodynamic mismatch was cited as the most significant contraindication. Beta-blockade appears to exacerbate an already compromised hemodynamic profile of HTN in this patient group, which is characterized by a low cardiac output and an elevated systemic vascular resistance.
Implications for Practice
This analysis supports the recommendation that beta-blockers no longer be considered for initial monotherapy of HTN in the elderly. One concern is the author's definition of elderly, which includes the "young-old" (60-70 years), who may be more physiologically similar to middle-aged patients, about which the authors acknowledge "some indirect evidence suggests that B-blockers may have some benefits in treating HTN."
It is paramount that we individualize HTN therapy not only according to patient age, but to type of blood pressure and potential co-morbidities. For example, benefits of treating elderly patients with isolated systolic HTN have been demonstrated for the calcium antagonists.3 We don't know if other classes of drugs, the angiotensin-converting enzyme (ACE) inhibitors, the ACE-II receptor blockers, and/or the new combined alpha and beta-blockers confer the same or improved outcomes compared to diuretic monotherapy. There are clinical situations in which they may be more appropriate. Combination agents may prove to be superior and better tolerated (albeit at a high cost to the consumer). At present, however, the question appears to have been answered. In uncomplicated essential hypertension in the elderly, diuretics are the only class of drug appropriate for consideration as first line monotherapy.
References
1. The National High Blood Pressure Education Program Coordinating Committee. The sixth report of the joint national committee on prevention, detection, evaluation, and treatment of high blood pressure. Arch Intern Med 1997;157:2413-2446.
2. Messerli FH, Grossman E, Goldbourt V. Are B-blockers efficacious as first-line therapy for hypertension in the elderly? JAMA 1998;279:1903-1907.
3. Staessen JA, Fagard R, Thijs L, et al for the Systolic Hypertension-Europe (Syst-Eur) Trial investigators. Randomised double-blind comparison of placebo and active treatment for older patients with isolated systolic hypertension. Lancet 1997;350:757-764.
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