SECOND OPINION:Hypertension puts health of ageing population in danger, writes EOIN O'BRIEN
HIGH BLOOD pressure or hypertension is the most important risk for stroke. Many people are aware of this but few realise that the prevention of stroke is dependent on effective drug treatment so that blood pressure is brought down to normal levels. I suspect that even fewer people will know that deteriorating mental performance and dementia are now also associated with high blood pressure, which makes the control of blood pressure all the more important as longevity increases.
In Ireland, as in other western societies, high blood pressure is a very common illness affecting about one-third of the adult population. However, as we get older, hypertension becomes much more common, and over the age of 70 the great majority of people have elevated blood pressure. As society ages, so too will high blood pressure become even more common. Soon some 14 per cent of Irish people will be over the age of 65 and a quarter of these will be over 80.
The inevitable consequence of the combination of an ageing population and the accompanying rise in blood pressure is that the 10,000 strokes that occur each year in Ireland must increase substantially unless preventive action is taken. The most effective preventive strategy would be to achieve blood pressure control in people with hypertension – if this was done the number of strokes occurring each year in Ireland could be halved.
However, the reality is that in Ireland (in common with most other European countries) less than half the people with high blood pressure know they have it, less than half of those who know they have it are on treatment, and less than half of those who are on treatment are being treated effectively – the infamous “rule-of-halves”.
A document published recently by the Irish Heart Foundation, entitled Cost of Stroke in Ireland; Estimating the Annual Economic Cost of Stroke and Transient Ischaemic Attack (TIA) in Ireland”, would seem, therefore, to be timely in that it should guide future policy for our healthcare providers.
However, when it comes to the economics of prevention, the document is seriously flawed. In the light of the evidence I have quoted on the association of high blood pressure and stroke, how is it possible that in a 120-page document dealing with the cost of stroke, the savings from effective management of high blood pressure are not considered?
The authors estimate that stroke will cost the nation €805 million per annum, which is 4 per cent of the total health expenditure and 0.3 per cent of GNP – a truly staggering figure. The report then makes recommendations as to how this amount might be reduced. Firstly, the provision of stroke units could save €10 million; secondly, thrombolysis (clot-dissolving treatment) could cut another €3 million; and finally, if 10 per cent of patients with atrial fibrillation (irregularity of the heart) were adequately treated with warfarin, 70 new strokes could be avoided in one year.
None of these measures is to be decried but unbelievably the major saving – control of high blood pressure – is completely ignored. If we start from the ideal goal of obtaining blood pressure control in all the patients with hypertension, there is a potential saving of some €400 million, but let’s assume that we begin modestly and aim to achieve blood pressure control in half that number, we could then take €200 million off the annual bill and we still have the potential to go on to greater savings once the processes are in place to manage hypertension effectively.
Achieving these savings calls for a new approach to blood pressure management. We have effective drugs to lower blood pressure without adverse effects. However, we do not use these drugs effectively and we do not utilise the technique of ambulatory blood pressure measurement sufficiently to ensure that we are obtaining control of blood pressure over the entire 24-hour period.
Presumably, the HSE and the Department of Health will base their strategies for future policies on the data in the Cost of Stroke in Ireland. In doing so, their financial advisers would be well advised to heed the very significant cost reductions to be gained by concentrating resources on achieving blood pressure control in Ireland – a strategy not considered in this document.
Eoin O’Brien is professor of molecular pharmacology at University College Dublin