Dr David Brodie argues that the SIGN hypertension guideline for older people is sometimes difficult to apply in practice

The SIGN guideline on hypertension in older people1 is exhaustive and very thorough. However, what is discussed often seems to bear little resemblance to what I find in practice.

For many of my hypertensive patients drug treatment either does not work, does not suit them, or is something in which they do not wish to indulge. The problem is that hypertension is asymptomatic, so patients have to be persuaded to take the condition seriously. Many are never truly convinced.

A patient came to see me a couple of months ago and gave me a discharge note from a local hospital. To my surprise, this informed me that he had had a dissection of the arch of his aorta.

He had first come to see me 5 years ago, having found that he was suddenly unable to write. I had measured his blood pressure, which was astronomical, and sent him to hospital. He had experienced a lacunar infarct, but had subsequently neglected to take his medication or have his blood pressure measured until the most recent event.

On the other hand, I have two patients whose blood pressure has been very well controlled for 15 years. Despite having no other risk factors, they have both had myocardial infarctions within the last 5 years.

It is therefore worth examining the guideline for hypertension against the backdrop of a difficult and sometimes disheartening challenge for GPs.

The emphasis on a therapeutic grey area for hypertension is helpful. Mild hypertension is classified by a blood pressure of 140–159/90–99mmHg. In all such cases, lifestyle measures are recommended. Treatment should be started for patients with a 10-year CHD risk of >15%, or target organ damage. Patients without these risk factors should be assessed yearly.

Target organ damage is similarly easier to offer guidance about than to detect. My main concern is those hypertensive patients with left ventricular hypertrophy who are undiagnosed. An echocardiogram is more accurate than an electrocardiogram, but I do not have direct access to echocardiography.

The blood pressure target of <140/90mmHg is a 'reasonable goal', although it seems odd that this is also the threshold for treatment. Targets for patients with extra risk factors are understandably lower. I feel less confident about draconian hypertensive control in the over-80s but, encouragingly, the guideline points to evidence of benefit in very old people.

Treatment options still centre on initiating treatment with thiazides or beta-blockers. I prefer to tailor treatment to the patient. The guideline points out that we can use long-acting dihydropyridine calcium antagonists either as alternatives to thiazides or as supplementary treatment, particularly in isolated systolic hypertension.

It also states that there is still no evidence that alpha-blockers prevent clinically important end-points and that they should not be used as first-line treatment. The guideline cites a review of the Antihypertensive and Lipid-lowering Treatment to Prevent Heart Attack trial,2 in which the doxazosin arm of the trial was discontinued because a higher proportion of patients developed congestive cardiac failure.

Perhaps the biggest challenge for GPs is to ensure that we identify our hypertensive patients, and at least attempt to investigate and treat them effectively.

References

  1. Scottish Intercollegiate Guidelines Network. Hypertension in Older People. Edinburgh: SIGN, January 2001.
  2. Messerli FH. Implications of discontinuation of doxazosin arm of ALLHAT. Lancet 2000; 355: 863–4.

Guidelines in Practice, June 2001, Volume 4(6)
© 2001 MGP Ltd
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