systolic hypertension (hypertension in the elderly)

Introduction

Systolic BP >150 with diastolic BP < 90.

As good or better predictor of cardiovascular morbidity than diastolic hypertension.

24 hour ambulatory systolic BP better predictor of all-cause & cardiovascular mortality than clinic systolic BP

Nighttime systolic BP better predictor of all-cause & cardiovascular mortality than daytime systolic BP

Systolic BP increases throughout the 7th decade of life, but diastolic BP plateaus in the 5th decade.

Etiology

• disorders associated with increased cardiac output
  • anemia
  • thyrotoxicosis
  • arteriovenous fistula
  • Paget's disease of the bone
  • beriberi
• increased cardiac stroke volume
  • aortic insufficiency
  • complete heart block
• atherosclerosis (hardened, less compliant arteries)
• elderly may have high systolic blood pressure simply by exertion of walking into the exam room

Epidemiology

• 90% of patients with hypertension over 70 years of age have isolated systolic hypertension
• older adults with hypertension often receive intensification of blood pressure treatment at hospital discharge, even if blood pressure was well-controlled before admission

Pathology

• elastic properties of the aorta allow it to expand during systole
• with age
  • elastin fibers degrade
  • collagen fibers increase
  • the aorta becomes more rigid
• with rigidity, pulse wave velocity increases
• the reflection of the pulse wave from the periphery back to the heart is accelerated with vascular rigidity
• the reflected wave normally reaches the ascending aorta in early diastole, augmenting early diastolic pressure
• the faster pulse wave with vascular rigidity results in the reflected wave reaching the ascending aorta in late systole rather than early diastole

Complications

• older patients with hypertension are at increased risk of cardiovascular events vs younger adults, but are more vulnerable to adverse effects of lowering blood pressure; frailty is a predictor of such vulnerability
• greater risk of hypotension & possibily syncope with intensive therapy
• increased risk of falls with treatment
  • a history of fall injury in the past year doubled the risk of serious fall
  • higher dose of antihypertensive medication is independently associated with falls in the elderly
  • intensive therapy not associated with increased risk of falls
• treatment may increase risk of cognitive impairment in the very old & result in decline of physical function
• higher BP is associated with better cognitive function in the oldest old (>= 85 years of age)
• orthostatic hypotension renders elderly with mild cognitive impairment twice as likely to become demented
• people with the lowest BP levels (90-114)/(60-74) mm Hg with the lowest risk for cardiovascular disease (huge study 5 year followup)*
• association of blood pressure with cardiovascular disease decreases with increasing age*
• systolic hyypertenion is strongly linked to intracerebral hemorrhage, subarachnoid hemorrhage, & stable angina, but only weakly to abdominal aortic aneurysm*
• increased risk of 30-year cardiovascular mortality in persons < 50 years
• higher visit-to-visit variability in systolic BP is associated with increased risk of cardiovascular events in patients with systolic hypertension
• increased risk of atrial fibrillation
  • lowering systolic BP lowers risk of new-onset atrial fibrillation
• primary care providers rarely stop or lower antihypertensive doses for older patients, even if they achieve recommended targets
  • only 19% of VA primary care providers reduced antihypertensive treatment in older persons with very low blood pressure
• in older adults with unplanned hospitalizations, frailty or polypharmacy, starting antihypertensive treatment is linked to acute kidney injury & risk of falls
• an early drop in eGFR of > 15% with intensive treatment (< 4 months) is associated with increased risk of end-stage renal disease

* see ambulatory blood pressure monitoring for risks associated with systolic hypertension during sleep

• disease interaction(s) of chronic hypertension with Alzheimer's disease (AD)

Management

• initially, lower systolic BP carefully to 160 mm Hg
• final goal:
  • systolic BP of < 150 mm Hg (also JNC8)
  • goal is < 140 mm Hg for patients with history of stroke or TIA & some patiemts with high cardiovascular risk (diabetes mellitus, chronic renal failure)
    • systolic BP targets of <130 mm Hg or <140 mm Hg result in similar BP reductions
    • systolic BP target of <130 mm Hg may be reasonable if 10 year risk of cardiovascular disease is > 15%
    • systolic blood pressure goal of 110-130 mm Hg no better than 130-150 mm Hg for cognitive function in elderly 60-80 years with systolic hypertension
    • SPRINT study finds targeting systolic blood pressure to < 120 mm Hg results in reduced risk of minimal cognitive impairment relative to target of < 140 mm Hg (RR=0.8) - see SPRINT study
  • goal may be higher, i.e. 160 mm Hg in very old
  • ref cites target of 140-145 mm Hg for patients > 80 years
  • lowest mortality of systolic blood pressure of 140 mm Hg in elderly > 80 years of age with coronary artery disease
  • systolic BP < 120 mm Hg proposed by Sprint study investigators
    • associated with least cognitive decline
    • patients reported outcomes similiar to JNC8 guidelines
    • cost effective
  • systolic BP < 140 mm Hg may be appropriate for some adults > 60 years with life expectancy of > 3 years
    • NNT: 100 patients for 3 years to prevent 1 major cardiovasculr event
  • lowering systolic blood pressure to < 130 mm Hg in frail elderly with systolic hypertension may worsen cognitive decline
  • lowest risk of dementia in elderly > 75 years is 158 mm Hg
  • lowest risk of mortality in elderly > 75 years is 160 mm Hg
• keep diastolic BP > 70 mm Hg (65 mm Hg, 60 mm Hg)
  • diastolic BP < 70 mm Hg may increase risk of stroke & myocardial infarction
  • J-shaped blood pressure-mortality curve with minimal mortality at diastolic BP of 75-85 mm Hg
  • overtreating systolic blood pressure at the expense of diastolic blood pressure can worsen outcomes
• automated blood pressure cuff readings correlate better with ambultory blood pressure than manual readings
• systolic blood pressure tends to fall with (> 10 mm Hg) during a 10 minute rest period
• aggressive treatment of systolic hypertension in frail elderly with multiple comorbidities might not be necessary & could be harmful
  • decreased mortality with higher blood pressure in fail elderly
  • 2 or more antihypertensive agents in the elderly associated with low systolic BP (< 130 mm Hg) & higher mortality (RR=1.8)
  • orthostatic hypotension renders elderly with mild cognitive impairment twice as likely to become demented
  • similar rates of injurious falls & cardiovascular events after initiating any first-line antihypertensive in elderly with limited life expectancy
• cardiovascular benefit to treating systolic hypertension depends on age & gender
• discontinuation of antihypertensives in elderly (> 75 years) with mild cognitive impairment for 16 weeks without benefit or harm
• nighttime hypertension may be associated increased risks for diabetes mellitus type 2, cardiovascular risk & heart failure
  • taking antihypertensives at bedtime may reduce these risks
  • morning vs night dosing with similar rates of cardiovascular outcomes
• meta-analysis concludes pharmacological blood pressure reduction is effective into old age, with no evidence that relative risk reductions for prevention of major cardiovascular events vary by systolic or diastolic blood pressure levels at randomisation, down to less than 120/70 mm Hg
  • the group analyzed their own data to support their conclusions
  • no discussion of diet or lifestyle changes, quality of life or cognition
  • no benefit found in elderly over 85 years
• a systematic review of blood pressure guidelines in the elderly
  • conclusions differ from ref
• see chronic hypertension for specific treatment
  • in elderly, beta-blockers are less effective in lowering blood pressure & improving outcomes than other antihypertensives
  • antihypertensives that stimulate vs inhibit type 2 & 4 angiotensin II receptors may result in a lower risk of dementia (see angiotensin II type 2 & 4 stimulating agent)

Clinical trials

• Systolic Hypertension in Elderly Program (SHEP) trial
• Systolic Hypertension in Europe (Syst-Eur) trial
• also see blood pressure in the very old for clinical trials in patients > 80 years of age
• Sprint study target systolic BP of 120
  • SPRINT group reports reduction in mild cognitive impairment, but not dementia using SPRINT goals (14.6 vs 18.3 per 1000 person-years)
• STEP trial 8,500 patients ages 60-80 in China
  • target systolic blood pressure 110-130 mm Hg
  • 26% reduction in risk of stroke, acute myocardial infarction, hospitalization for unstable angina, acute decompensated heart failure, coronary revascularization, atrial fibrillation, or cardiovascular death
  • benefit independent of baseline diastolic blood pressure
  • no mention of all-cause mortality, quality of life, cognition or falls

More general terms

• chronic hypertension

Additional terms

• blood pressure in the very old
• Systolic Hypertension in Elderly Program (SHEP) trial