31 August 2011
Home is where the heart is
The National Institute for Health and Clinical Excellence (NICE) has finally made a pronouncement on 24-hour blood pressure monitoring about ten years after more advanced Primary Case Teams purchased their own machines, it was reported last week. You can see articles in the Daily Telegraph and on the BBC website.
Yet again, we must remember that NICE is a government-funded organisation and the cost of any treatment is high on their agenda. So, not treating people with hypertension is quite an attractive option although the consequent cost of any cardiovascular event is not to be sneezed at.
The Primary Care Training Centre has been recommending what is also called “Ambulatory Blood Pressure Monitoring” for the whole of this 10-year period and I cannot do better than to print the advice from the Distance Learning Pack of the Cardiovascular Disease Prevention Course:
Blood pressure control over the whole 24-hour period is really important. Ambulatory blood pressure monitoring can assess both the average blood pressure over the 24 hours and provide other useful prognostic information. The blood pressure fluctuates dramatically over the course of a day and night almost from second to second.
For instance, the blood pressure and heart rate rise rapidly in the morning between 6.00 and 10.00am. This coincides with the time that most heart attacks and strokes occur. At night, the blood pressure falls. Patients whose blood pressure does not do this are called “non-dippers” and are at a higher risk of a cardiovascular event.
As well as identifying patients who need anti-hypertensive therapy, it is also important to identify those who do not. Some patients have what is known as “white-coat hypertension”. The blood pressure readings when taken in a surgery or clinic are much higher than those taken at home or on 24-hour monitoring. These patients do not need drug treatment but are at risk of developing hypertension and hence need careful monitoring.
Those with definite, unequivocal hypertension do not need a 24-hour reading, plainly intervention is mandatory. Who therefore should have a 24-hour reading performed? Essentially, there are five groups:-
i] Those with borderline hypertension where decision to treat or not would be helped by a 24-hour average.
ii] Those where “white coat” response is suspected. There is a proportion of patients, which may be as high as 15-30% of those with raised blood pressure, whose blood pressure always goes up in the presence of a doctor or nurse. A 24-hour reading would be invaluable in preventing unnecessary treatment.
iii] Those whose hypertension is apparently resistant to treatment and a decision has to be made as to whether to add a third or fourth drug to the regime.
iv] Those with suspected hypotension
v] Patients in whom really tight blood pressure control is needed. For instance renal failure and diabetes.
Despite this, some experts still argue that blood pressure at any time is important and should be treated.