Please note: In 2003, the CTF updated its Grades of Recommendations to include an "I Recommendation" for situations where insufficient evidence exists to allow a recommendation to be made. (Formerly, these situations were captured under a "C Recommendation".) This change is not retroactive, and all "C Recommendations" made prior to 2003 have not been reevaluated in light of the new "I" recommendation grade. For a discussion of these recommendation grades, please link to the 2003 article in the Canadian Medical Association Journal here.
Contents
OverviewBurden
of SufferingEpidemiological studies, for example those arising from Framingham, Massachusetts have determined that the risks of death and morbid events relate independently to both systolic and diastolic hypertension. The risks of stroke and of cardiovascular diseases rise with age, given the same levels of BP. Thus, the rate of morbid events is age-dependent, for both men and women. In general, rates for men are higher than for women of the same age with similar levels of BP. Moderate degrees of hypertension are usually asymptomatic in all age groups.
ManeuverEffectiveness
of Prevention and TreatmentThe European Working Party on High Blood Pressure in the Elderly Trial (EWPHE)<4> examined antihypertensive treatment in 840 patients over 60 years of age. These patients were recruited from hospital clinics using a sitting systolic BP of 160-239 mmHg and a sitting diastolic BP of 90-119 mmHg as entry criteria. Treatment was randomized and double-blind, using diuretics as first line treatment, subsequently adding methyldopa as necessary. After an average follow-up of nearly 5 years, there were less than 300 subjects remaining in the study (19% had died, 4% had a trial-terminating morbid cardiovascular event, 4% had a terminating non-morbid event, and 36% had left the study prematurely for other reasons). The results included a significant reduction in cardiovascular mortality (-27%, p=0.037); significant reduction in cardiac mortality, (-38%, p=0.036) and study-terminating morbid cardiovascular events were significantly reduced by 60% (p=0.064). There was a non-significant change in all cause mortality and in cerebral vascular mortality.
Criticisms of this study included the very slow recruitment rate and high dropout rate. Calculation of the number needed to treat for5 years (NNT5) was 23 to reduce one cardiovascular death, and 37 to reduce one nonfatal cerebral vascular event (cardiovascular accident, transient ischemic attack). While no benefit was seen in subjects over age 80, only 155 completed the trial. Further analysis of the EWPHE trial indicated that the benefit of treatment occurred throughout the range of blood pressures included in the trial, whether or not the patient had cardiovascular complications at entry.<5,6>
The Systolic Hypertension in the Elderly Program (SHEP)<1,7> recruited over 4,000 subjects after a mass screening of 447,921 people over age 60. Entry criteria included systolic BP between 160 and 219 mmHg, with a diastolic BP less than 90 mmHg. Those with a history or signs of major cardiovascular diseases were excluded. The mean age of the subjects was 72 years, although 649 were over the age of 80. Treatment was randomized and double-blind, commencing with a diuretic, with beta-blockers or reserpine as second line treatment. Treatment targets were a systolic BP of less than 160 mmHg if the initial systolic BP was greater than 180 mmHg, and a reduction of 20 mmHg of mercury if initial systolic BP fell between 160 and 180. There was a significant reduction in the incidence of total stroke by 37% (p=0.0003: relative risk 0.63; 95% Confidence Internal (CI): 0.49-0.82). The incidence of myocardial infarction was reduced by one third (relative risk 0.67; 95% CI: 0.47-0.96). The incidence of left ventricular failure was reduced by one half (relative risk 0.46; 95% CI: 0.33-0.65). There was a nonsignificant reduction in all cause mortality. The NNT5 for reduction of one stroke was 40, as it was for left ventricular failure. The NNT5 to reduce a myocardial infarction was 90.
The Swedish Trial in Older Patients with Hypertension (STOP-Hypertension) was a randomized trial involving Swedish men and women between the ages of 70 and 84.<8> The entry criteria were systolic BP between 180 and 230 mmHg plus a diastolic BP of at least 90 mmHg, or a diastolic BP between 105 and 120 mmHg irrespective of systolic pressure. Treatment was randomly allocated to four drugs, one diuretic combination and three beta-blockers. This study did not exclude those with other cardiovascular diseases, except for myocardial infarction or stroke within one year, or angina requiring more treatment than glyceryl trinitrate. After an average treatment time of slightly over two years, there was a significant reduction in all cause mortality (relative risk 0.57; 95% CI: 0.37-0.87). There was a significant reduction in all strokes (relative risk 0.53; 95% CI: 0.33-0.86) and a significant reduction in fatal strokes (relative risk 0.27; 95% CI: 0.06-0.84). Treatment benefits were evident in the primary endpoints at all ages, although above age 80 the benefit was not clear. The NNT5 to prevent one stroke or death was 14.
The Medical Research Council (MRC) trial of treatment of hypertension in older adults studied the effects of antihypertensive treatment in men and women between the ages of 65 and 74 with systolic BP between 160 and 209 mmHg together with a diastolic BP of less than or equal to 114 mmHg.<9> Nearly 185,000 invitations were issued to patients in over 200 family practices. Over 20,000 were eligible for consideration, but 16,000 of these were excluded due to: prior treatment for hypertension, myocardial infarction or stroke within three months; or significant cardiovascular or other diseases. Treatment was placebo- controlled and double-blind and initiated with either diuretic or beta-blocker. The study continued for over 5 years by which time 25% of the subjects had been lost to follow-up.
The trial showed a significant reduction in all strokes of 25% (p=0.04; 95% CI: 3-42%). There was a reduction of all cardiovascular events (stroke and coronary events) of 17% (p=0.04; 95% CI: 2-29%).
These four trials confirm the beneficial effects of initiating treatment in older subjects with systolic BP >160 mmHg, and diastolic BP >90 mmHg. Treatment with diuretics is usually effective although the addition of second line drugs is often necessary.
While an exhaustive search for causes of secondary hypertension is not recommended, drugs such as alcohol and nonsteroidal anti-inflammatory drugs may contribute to blood pressure elevation.
Health promotion measures such as reduction of intake of salt, cessation of tobacco use and regular exercise are usually recommended, and may influence cardiovascular disease or hypertension risk, particularly if it is borderline. Pharmacological treatment should not be delayed in those with moderate or severe hypertension.
There is evidence that conveying a diagnosis of hypertension to younger subjects may foster the development of symptoms.<10> Whether this is true in older patients is not clear.
Recommendations
of OthersConclusions
and RecommendationsAs with management of elderly in general, close attention must be paid to the development of side effects of medications. The risks of treatment must be weighed against possible benefit in those suffering from coexistent severe diseases, such as dementia and advanced stages of other diseases.
Unanswered
Questions (Research Agenda)EvidenceAcknowledgements
Link to Structured Abstract of this review
Link to Summary Table of this review
Link to Selected References list of this review
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Last modified March 27, 1998.
