Hypertension as a modifiable risk factor remains the leading cause of death globally, accounting in 2020 for 1.4 billion deaths that year. This number is increasing despite the major efforts of international organisations, improved training of healthcare professionals and patient awareness campaigns.
Hollywood & Curtin Medical School
Major global associations such as the International Society of Hypertension, the American Society of Hypertension and the European Society for Hypertension have special working groups monitoring the global burden of hypertension and its end-organ damages and deploy major initiatives to mitigate these and come up with guidelines.
As so often with guidelines, there is no worldwide consensus about the treatment of hypertension because of different reasons for hypertension in different parts of the world, the ability to screen for secondary causes and the availability of certain medications.
Regretfully, the guidelines are often generic, focus on common comorbidities, and give little specifics about how to treat hypertension in the elderly, who are an often difficult-to-treat subgroup.
Hypertension in the elderly comes with unique challenges that cannot be compared to younger age groups, and hence requires a very different approach to the treatment.
Systolic blood pressure continuously rises with age, partly as a physiological principle (lack of cerebral blood flow autoregulation, requiring higher systolic blood pressure), but also ageing consequences such as arterial stiffness.
In general, after the age of 55, the diastolic blood pressure declines, thus increasing pulse pressure. Whereas the guidelines have dictated for many years low blood pressures for all ages, awareness has grown that the elderly require a higher blood pressure to maintain sufficient brain and other vital organ perfusion.
At the same time, this is a precarious balance, as these patients obviously are also more at risk for stroke. In ageing people, the risk of cardiovascular events and mortality remains directly related to the systolic pressure but is inversely related to the diastolic blood pressure.
The question remains, what is an acceptable blood pressure for an individual over 60 years of age?
Whereas for younger patients this has quite firmly been established at 115-125/75-80, for the elderly there is not such a rule. At an older age, too many co-factors come into play that have their own influences on cardiovascular and cerebrovascular health (ischaemic heart disease, diabetes, hyperlipaemia, heart failure, etc).
The SHEP (Systolic Hypertension in the Elderly) Trial, and the STOP (Swedish Trial in Old Patients with Hypertension), showed a significant reduction in cardiovascular events if the blood pressure was maintained below 145/90, resp 143/78.
Studies in the elderly over 80 years of age, where typically clinicians become reluctant to treat elevated blood pressure, showed benefits if blood pressure could be targeted at 142/78. There was a negative effect on the results with a diastolic pressure below 60 mmHg. These studies were not controlled for secondary effects of treatment (such as falls) due to a too-significant drop in blood pressure and the consequences of such trauma, especially since this group is frequently using anticoagulants.
For this reason, it is highly recommended not to rely on office blood pressures alone but do at least once a 24-hour ambulatory blood pressure measurement study.
Another factor that is stressed in literature is the concept of ‘frailty’, be it as general condition or secondary to another disease such as Parkinson’s where higher blood pressures will need to be tolerated to prevent the patient from falling and the blood pressure reduction would do more harm than good.
The question what drug to use in the elderly is not consistently answered in the literature. Whereas in younger generations an ACE inhibitor or Angiotensin Receptor Blocker, if needed, followed by a Dihydropyridine and potentially after that hydrochlorthiazide is considered, in the elderly, especially those with frailty, a thiazide diuretic may be the first choice, followed by a non-dihydropyridine calcium antagonist, and only then an ACE inhibitor or Angiotensin Receptor Blocker.
Beta blockers should, given their profound effect on the heart rhythm, be kept for compelling indications. It needs to be said, that no hard data is available to back this up, and again, studies give conflicting results in the elderly.
Key messages
- Hypertension has equally deleterious effects in the elderly as in young patients, although there is a difference in the weight of systolic versus diastolic pressures
- For physiological reasons, a slightly higher blood pressure in the elderly should be accepted
- The choice of anti-hypertensive medication in the elderly differs from the guideline-proposed drugs for younger generations.
Author competing interests – nil