Hypertension in The Elderly - Evidence Broadly Supportive, but Uncertainties Remain

It’s almost 10 years since the SPRINT trial changed the landscape of hypertension treatment, by showing that intensive antihypertensive treatment to a systolic target of 120 mm/Hg, compared to standard targets of 140 mm/Hg, significantly reduced cardiovascular events. The recently published ESPRIT trial has also shown reductions in a composite end-point of CV events and CV deaths when treating to a systolic of 120 mm/Hg. But it’s important to note both these trials looked at patients at higher risk of cardiovascular disease AND who were generally younger (mean ages in SPRINT ~67 years and in ESPRIT ~ 65 years). The associated editorial to ESPRIT importantly highlights that ‘the study findings might not extend to the growing group of older patients with multiple chronic conditions and frailty where more research is needed'.

So what to do about this very important and large group of older patients with hypertension? An article in the DTB a couple of months back (Drug and Therapeutics Bulletin 2024;62:149-155) gave an excellent overview of managing hypertension in older people, bemoaning the (relative) dearth of evidence for this group, and the many uncertainties and challenges in this age group, not least that there is no established definition or consensus as to what age constitutes ‘old’!

They highlight one of the challenges of treating hypertension in older adults is the changing pathophysiology as we age. There is a higher incidence of isolated systolic hypertension (ISH) in older adults, and this phenomenon together with an increased risk of autonomic dysregulation can cause orthostatic hypotension (OH) with it's well-known complications. In the context of ISH, there is evidence that below a certain diastolic BP (<60-65 mm/Hg) cardiovascular risk starts increasing again, which probably contributes to the ‘J-shaped ’curve seen with BP lowering.

What evidence do we have to help guide us? To date, there is no trial that has been specifically designed to look at antihypertensive treatment based on frailty status, but there is certainly evidence supporting the cardiovascular benefits of antihypertensive treatment in the elderly, notably from the HYVET trial.

What about the risks, especially for those with frailty? This remains a big gap in our knowledge, with much debate about what constitutes ‘significant ’adverse events. Broadly speaking the RCTs have not shown any increased risk of serious adverse events, whereas observational data from GP records does show increased risks of harm in those aged >80 with severe frailty treated with antihypertensives.

So what are the take-home messages for us when considering treating hypertension in the elderly? There are a number of useful conclusions from this DTB review:

1. Overall there is enough evidence to suggest that the benefits of hypertension treatment in older people outweigh the risks, including in those with frailty.

2. But clinical judgment and shared decision-making are essential given the paucity of evidence in the frail and very old, and the wide discrepancy in international guidelines.

3. Be aware of the ‘J-shaped curve ’and those with isolated systolic hypertension and diastolic BPs <60-65 mm/Hg - further treatment may increase their CVD risk.

4. If treating careful monitoring is required, including an assessment for orthostatic hypotension (if postural hypotension use standing BPs as per BIHS guideline), with a ‘start low, go slow ’approach initially with monotherapy, but also be aware of therapeutic inertia!

5. CCBs, ACEI/ARB or thiazides are all reasonable drugs to consider depending on preference and comorbidities, but avoid alpha-blockers (higher risk of OH).

6. But much greater caution is needed in those with severe frailty and limited life expectancy - we need to remember that all trials show the CVD benefits of antihypertensive treatment take years, not months, to become apparent.