Symposium: The new ESC-EHS guidelines on hypertension. 722004
Austria, Vienna, Sunday 2 September 2007:
In 2000, 26% (972million) of the adult population worldwide had hypertension and this figure is estimated to rise by 2025 to 1.56billion. Such individuals have an increased risk of stroke or heart disease and the detection and effective management of such patients presents an enormous challenge to healthcare systems. Identifying specific patients at risk of developing organ damage will allow better deployment of preventative healthcare resources.
Against this background, the European Society of Cardiology and the European Society of Hypertension have revised their 2003 guidelines based upon the publication of new evidence. The cornerstone of treatment remains the introduction of lifestyle measures such as increasing exercise, reducing body weight and other environmental factors such as reducing the intake of alcohol and salt before embarking on a treatment programme involving drugs.
Three issues then follow: First, identifying the high-risk patient. The new guidelines continue to stratify patients according to level of presenting blood pressure and the detection of other risk factors -- metabolic syndrome, sub-clinical organ damage or diabetes or finally, established cardiovascular or renal disease. The two latter categories place patients at moderate to very high risk and of course, treatment should be very aggressive.
The second issue is the class of drugs to be used. The ESC and ESH agree that the most important factor in reducing an individual’s cardiovascular risk is lowering blood pressure. Against this background, there is some evidence emerging that particular classes of drugs may have the ability to protect against specific organ damage. Although this is intriguing further investigation is needed to verify the evidence. Newer classes of drug, for example, may be able to prevent the development of Type 2 diabetes or at least delay the onset of this problem, which inevitably rapidly increases an individual’s cardiovascular risk.
Another interesting area is the detection of sub-clinical organ damage. Initially this was largely confined to the detection of albuminuria or elevated creatinine, which is not only important parameters for defining renal function and progressive renal failure, but also for delineating increased cardiovascular risk. However, as methodology has improved the measurement of intimal medial thickness and pulse wave velocity have become more generally acceptable and with these the possibility of again defining cardiovascular risk at an earlier time-point and with more accuracy. Similarly, microcalcification of medium sized blood vessels using high resolution CT scanning has been demonstrated to be important although of course the technology necessary to measure this is much more limited. However, the concept of earlier detection of vascular damage and the recognition that it is extremely prognostically important means that we have new ways of characterising the risk associated with patients and a fresh impetus to interfere with blood pressure levels at a much earlier point to prevent irreversible end-organ damage.
The third issue is the target level to be achieved. This has largely remained unchanged from 2003 with the target for the majority of patients being 140/90mmHg or less. In patients at higher risk with Type 2 diabetes and hypertension, this level is 130/80, which is now extended to patients with previous history of stroke or evidence of renal dysfunction. The importance of detecting and treating hypertension cannot be overestimated -- effective treatment of hypertension reduces the risk of developing stroke by more than 40% with almost immediate impact and on coronary artery disease, over a period of several years the risk will be reduced by more than 20%. This increasing healthcare problem needs to be tackled promptly and efficiently in an ever enlarging cohort of asymptomatic patients.