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.

Hypertension in the Elderly: Case-Finding and Treatment to Prevent Vascular Disease

Prepared by Christopher Patterson, MD, FRCPC, Professor and Head, Division of Geriatric Medicine, McMaster University, Hamilton, Ontario, and Alexander G. Logan, MD, FRCPC, Professor of Medicine, University of Toronto



Objective
To make recommendations about case-finding and treatment of hypertension in elderly persons in Canada. This updates a 1984 Task Force report.

Burden of Suffering
Systolic hypertension is defined as an average blood pressure (BP) >160 mmHg measured on multiple readings on several occasions by sphygmomanometer cuff.  Diastolic hypertension is an average diastolic BP (Korotkoff V) ?90 mmHg.  The prevalence of isolated systolic hypertension (systolic BP >160 mmHg, diastolic BP< 90 mmHg) on two occasions) was about 10% of white Americans over 65 years of age, in the screening phase of the Systolic Hypertension in the Elderly Program (SHEP) study.  The prevalence rose to 20% in those over age 80 years.  The prevalence of diastolic hypertension (diastolic BP >90 mmHg on two occasions) was found to be about 11% of white Americans and over 26% of black Americans in the screening phase of the Hypertension Detection and Follow-up Study.  Other estimates based upon single measurements of BP have estimated prevalence considerably higher than these figures.

 Epidemiological 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.

Options
The only case-finding measure was the mercury sphygmomanometer. Treatment focused on drug therapy using diuretics, beta-blockers, methyldopa and reserpine.

Outcomes
Mortality (all-cause, cardiovascular/cardiac, cerebral vascular), morbid cardiovascular events (including myocardial infarction, left ventricular failure) and stroke (all, fatal).

Evidence
MEDLINE was searched to 1993 using the MeSH headings "hypertension", "aged", "aged over 80" and publication type "clinical trial". Other data sources were recent meta-analyses, review articles and input from experts. Study results were synthesized in table or graphic format only.

Values
The 13-member Task Force of experts in family medicine, geriatric medicine, pediatrics, psychiatry and epidemiology used an evidence-based method for evaluating the effectiveness of preventive health care interventions. Recommendations were not based on cost-effectiveness of options. Patient preferences were not discussed.

Background papers providing critical appraisal of the evidence and tentative recommendations prepared by the chapter author were pre-circulated to the members. Evidence for this topic was presented and deliberated upon in 1- to 2-day meetings, 2 to 3 times per year from January 1993 to June 1993. Consensus was reached on final recommendations.

Benefits, Harms, and Costs
4 RCTs confirm the benefits of drug therapy for older persons with systolic blood pressure (BP) > 160 mmHg and diastolic BP >90 mmHg. Major results are summarized below. To allow for comparisons, relative risks have been converted to relative risk reductions1. Converted results are indicated by { }.
 
Study Design and Patients
All-cause Mortality
Cardiovascular Mortality
Cardiovascular Events
Strokes
European Working Party on High Blood Pressure in the Elderly Trial
NS
RRR 27%
p = 0.04
NNT52 = 23
RRR 60% 
p = 0.06
NNT5 = 37 (nonfatal cerebral vascular event)
  
Systolic Hypertension in the Elderly Program
NS
  
RRR 33% 
CI3 4% - 53%
NNT5 = 90 (MIs)
RRR 37%
CI 18% - 51%
p = 0.0003
NNT5 = 40
Swedish Trial in Older Patients with Hypertension
{RRR 43%}
{CI 13% - 63%}
    
{RRR 47%}
{CI 14% - 67%}
NNT5 = 14 
Medical Research Council trial    
RRR 17%
CI 2% - 29%
p=0.04
RRR 25%
CI 3%- 42%
p=0.04
1 Relative risk reduction = 1 - relative risk
2 Number needed to treat over 5 years
3 95% confidence interval

Neither adverse effects nor costs of treatment were discussed.

Recommendations
Recommendation grade [A, B, C, D, E]  and level of evidence [I, II-1, II-2, II-3, III] are indicated after each recommendation. Citations in support of individual recommendations are identified in the guideline text.

Validation
This report was externally peer-reviewed. The 1989 U.S. Preventive Services Task Force recommended routine BP measurement in persons over age 3 years.

Sponsors
The Canadian Task Force on the Periodic Health Examination developed this guideline with funding from Health Canada.

Selected Referenecs

Source Document
Patterson C. & Logan A.G. Hypertension in the elderly: Case-finding and treatment to prevent vascular disease. In: Canadian Task Force on the Periodic Health Examination. Canadian Guide to Clinical Preventive Health Care. Ottawa: Health Canada, 1994; 944-51.

Other
Canadian Task Force on Periodic Health Examination. The periodic health examination. 2. 1984 update. Can Med Assoc J 1993;149:815-20.