BMH Medical Journal

BMH Med. J. 2020; 7(Suppl): Early Online. Geriatrics & Gerontology Initiative: International Workshop on Care of the Elderly

High blood pressure is an inevitable consequence of advancing age. When the office blood pressure (BP) is >140/90mmHg HYPERTENSION is generally diagnosed. As age advances, hypertension is more difficult to evaluate and treat. In hypertensive population, up to the age of 50-60 years both systolic and diastolic pressure rises. After that the diastolic BP gradually falls, but the systolic pressure continues to rise. Thus we get the peculiar problem of Isolated Systolic Hypertension (ISH) which is defined as SBP >140mmg Hg (in the very elderly people above 80yrs it is above 160mmHg) and DBP may be 90mmhg or lower. The overall prevalence of hypertension is 30-40% (age standardized) but in those above 80 years it may be seen in up to 80% of the population. In a person aged 55-60yrs risk of life time hypertension is >90%. Systolic BP (SBP) depends on both left ventricular performance and stiffness of aorta and large arteries and diastolic blood pressure (DBP) is determined by peripheral resistance, visco-elastic properties of arteries and diastolic duration. Change in these properties of arteries, increasing stiffness along with various metabolic abnormalities and endothelial dysfunction may cause impaired blood pressure homeostasis and variability of BP which may cause orthostatic hypotension. Associated neurological problems which not uncommonly affect elderly people, dehydration, poor nutrition and iatrogenic effects of various drugs compound the problem. All these worsen the situation and frequent fall is a serious consequence of untreated as well as treated cases of hypertension.

Key words: hypertension, elderly, diuretics, ACE-inhibitors, ARB, beta blockers, calcium channel blockers

Treatment of hypertension in the elderly is a huge challenge. One of the important problems of advancing age is cognitive impairment which may progress to dementia. Mild cognitive impairment (MCI), and dementia are observed in 40-50% and 15-20% respectively in persons above the age of 80 years in SPRINT SENIOR cohort. In chronic kidney disease (CKD) MCI is observed in over 60%.

Evidence for benefit of treatment in the elderly population has come over the last 3 decades. The SYST-EUR trial (Staessen et al, 1997), The SHEP (Systolic Hypertension in the Elderly Program) in 1991 and the PROGRESS (Perindopril Protection against Recurrent Stroke Study) (Tzouri et al, 2003) which all showed significant benefit in treating hypertension in the elderly to reduce cardiovascular events and stroke. More recently HYVET study (Beckett et al, 2008) showed benefits of treating the elderly even >80 years to reduce mortality and cardiovascular events. The celebrated SPRINT trial (Systolic Blood Pressure Intervention Trial) showed benefits for lowering BP to <120 mmHg systolic in patients >75 years after excluding those with loss of autonomy, cognitive disorders, diabetes and history of stroke. It was on this basis that the 2018 ACC/AHA guidelines advocated the objective of treatment of hypertension and to lower BP to the “normal” range of <120mmHg systolic. The ESC on the other hand based on HYVET recommended treatment of ISH to reduce BP to <150mmHg in 2013, but in 2017 they also lowered it to <140mmHg SBP, if there are side effects. There are some caveats here. Above the age of 80 years, evaluation for frailty and dependence is necessary. The very frail patients were excluded and only fit community dwelling persons were included. It should be mentioned that a BP level of 120mmHg in SPRINT trial was considered equivalent to 130-135mmHg systolic office recording.

Comparison of ACC/AHA and ESC/ESH Blood Pressure Thresholds

The relationship of BP lowering to cognitive decline has been a subject for numerous studies. In the SPRINT-MIND study in adults >50 years (average 68) intense BP lowering (SBP <120) versus standard therapy did not decrease dementia risk significantly, but as the study was terminated prematurely it was underpowered. In a meta-analysis of 12 studies on dementia and cognitive impairment, BP lowering reduced its incidence by 9% by better BP control over 4 years. Overall many studies gave inconclusive results about the benefit to prevent dementia by treating hypertension. In a very interesting study “The HONOLULU and ASIA ageing study”, 3735 subjects followed up over 30 years, it was shown that the risk of cognitive decline at 78 years was correlated with the BP level 25 years earlier. Mid-life BP level is more important as risk factor for cognitive impairment and dementia in late life than BP levels later in life. The Framingham study also observed that there was a decline in neurocognitive syndrome in the United States between 1977 and 2008, and was attributed to better control of BP during this period. Once cognitive impairment has set in lowering BP does not help them in recovery.

In the very old there is an inverse association between SBP and DBP with mortality as there is a decline of BP in the very old observed in the control population of HYVET study.

Management of hypertension in the elderly

The same 5 classes of drugs – diuretics, calcium channel blockers, Angiotensin Converting Enzyme (ACE)-Inhibitors and Angiotensin Receptor Blocker (ARB) and beta blockers are recommended for treatment of the elderly patients also. There are several challenges in managing hypertension, which is generally ISH in old age. Between the age of 65 years and 80 years there is overwhelming evidence for benefits in treating ISH. Above 80 years, one has to take into consideration factors like frailty, autonomy or dependence, presence of cognitive impairment, metabolic abnormalities, renal impairment, postural hypotension etc. Finally one must take into account patient preference. Shared decision making only after a frank discussion with the patient and relatives regarding the benefits and risks of treatment and the need for regular follow up and compliance, a final decision is to be taken. Some of the important points to be remembered are:

1) Make sure that there is more benefit than risk in treatment and communicate properly about the need for good follow up.

2) In the elderly, it is prudent to start with one drug which is the safest in the given patient taking into consideration risk profile, pharmacokinetics and pharmacodynamics of the drugs and explain what are the possible side effects to look for.

3) Always record BP in the sitting and erect position. Increase dosage or add another drug gradually depending on the response.

4) It should be remembered that many of the patient subgroups seen in real life situation were not included in the large trials, based on which guidelines were formulated. So the physician has to think beyond guidelines.

5) Diuretics are recommended as one of the first line drugs by guidelines, but many elderly patients develop hypotension, electrolyte imbalance or fatigue with it. A calcium channel blocker may be the safest to start with. Beta Blockers can cause severe bradycardia and ACE-Inhibitors may cause distressing cough but both may be indicated in some. ARBs may be tried as the second choice in most patients.

6) Life style measures are important, but dietary restriction in the very elderly can cause serious side effects. Elderly patients should take care before starting exercise program or even long walks on the side-walks of streets without prior assessment.

Conclusion

Hypertension is a well-recognized risk factor for atherosclerotic cardiovascular disease, stroke and renal failure at all ages. Benefits of reducing BP are observed in many large clinical trials and the well established guidelines endorse lowering of BP to <130/85 mmHg for all, but in the very elderly one has to take into consideration co-morbidities, postural changes, cognitive impairment and autonomy and so a higher target BP may be accepted in many. Shared decision making is essential in the elderly. One should be more concerned about the patient as an individual than mere blood pressure numbers. So for many elderly patients treatment does not always mean starting 1 or 2 drugs.

Hypertension In The Elderly - To Treat Or Not To Treat