Maximum tolerated dose: justifying your policy
Professor Graham MacGregor outlines how approaches to blood pressure are changing
1. Realistic population strategies to reduce high blood pressure
While we would like to see a reduction in weight and a reduction in excessive alcohol consumption and an increase in exercise, these are going to be very difficult to achieve. Far more practical is a reduction in salt intake.
In the UK, as in all developed societies, blood pressure rises with age. According to the Household Survey for England, at 20 years old, approximately 20 per cent of the population have raised blood pressure; at 40 years old, 40 per cent; at 60 years, 60 per cent; and at 80, 80 per cent. If we could slow down or prevent this rise in blood pressure we could reduce the need for people to receive drug treatment and, at the same time, lower population blood pressure which would have an immense effect on reducing heart attacks and strokes. Strategies should focus on salt intake which is the major factor in putting up blood pressure with age, and on increasing fruit and vegetable consumption because increasing potassium intake lowers blood pressure.
2. Wider use of validated automatic monitors
Patients are now advised to purchase their own validated automatic monitors. Accordingly, the BHS has produced a list, available on its website (www.bhsoc.org), of devices that have been tested to a strict protocol and met its criteria. Those that do not meet the BHS standards are not on the list. In testing, devices were graded (A-D) on how their measurements agree with a mercury standard for both systolic and diastolic measurements. Devices had to reach a minimum grade B to make it on to the list.
3. More patients monitoring own blood pressure
There is now a growing trend for patients, where appropriate, to take responsibility for their own blood pressure with support from health professionals, in exactly the same way as patients with diabetes control their blood sugar.
In individuals whose blood pressure is well controlled, they do not need to be seen by the practice and we are seeing examples of patients phoning in or e-mailing their own blood pressure levels.
Getting those with well-controlled blood pressure to take on this responsibility will free up GP and practice nurse time to focus on patients with poorly controlled blood pressure.
4. Question-mark over the role of ?-blockers in the treatment of hypertension
in the treatment of hypertension
Betablockers have a number of well known side-effects, as well as more subtle side-effects on enjoyment of life. Many of those who have taken betablockers will have experienced these effects. However, these subtle side-effects are not detectable in clinical trials and were, therefore, ignored by NICE. But very small impairments to the enjoyment of life are of huge importance to individuals with high blood pressure who feel extremely well and are then upset by the tablets for the rest of their lives.
The recent meta-analysis in preparation of the new NICE guideline confirmed that betablockers when added to diuretics are more likely to cause new-onset diabetes. The meta-analysis showed that one in 250 patients given the combination of a betablocker and a diuretic developed new-onset diabetes every year.
Over a 30-year period this would mean that one in eight individuals would develop diabetes an unacceptable risk.
There has also been some concern about the outcome trials with betablockers including a recent paper in The Lancet which demonstrated that, at least for atenolol, outcome was no better than placebo in preventing strokes and heart attacks.
My own view, therefore, based on the above is that betablockers should no longer be used for the routine treatment of high blood pressure. We have other equally effective drugs without the problems associated with betablockers.
Betablockers should be used where they have been proven to reduce mortality, ie heart failure where appropriate, post-myocardial infarction and symptomatic relief of angina.
And on its way....four things that the future holds
1Blood pressure rates will come down
This might seem like stating the obvious but we should realise the importance the Department of Health now places on bringing blood pressure down. Blood pressure earns more quality points than any other single category in the GMS contract.
The reason for this is that better control of raised blood pressure will result in a large reduction in strokes, heart attacks and heart failure.
The department has taken a strategic decision that it would be well worthwhile paying doctors in order to achieve this.
2More cases of hypertension to be uncovered. National Blood Pressure Testing Week gains momentum.
This event will run this year between September 12-18 and is organised by the Blood Pressure Association. Last year more than 200,000 individuals had their blood pressure measured.
The aim is for even more people to be measured this year and, particularly, to involve more practices and practice nurses as well as PCTs.
This will also help with the implementation of the GMS contract. For more information contact: www.bpassoc.org.uk
3Focus on salt
The Food Standards Agency is currently conducting a public campaign about the dangers of salt to the public. At the same time, both the agency and the Department of Health are gradually persuading the food industry and retailers to reduce the amount of salt added to food. This will result in a reduction in salt intake in the UK by the end of 2005. The campaign to illustrate the dangers of salt is going to continue throughout 2005, so that the public will be much more aware of the dangers of a high salt intake and aware of the dangers of high blood pressure.
4ASCOT study to be published
The ASCOT study has been stopped and the results will be available at the end of March 2005. The BHS guidelines are also likely to be revised once the results of the ASCOT study are known.
is professor of cardiovascular medicine,
St George's Hospital Medical School, London