Arterial 'prehypertension': a useful concept for drug companies, useless for patients.

(1) Elevated blood pressure is an independent and progressive cardiovascular risk factor. The risk starts to increase above a threshold of 115/75 mmHg. (2) The threshold values for blood pressure with practical implications for patients' health have been determined from clinical trial results. These are, for example, 160/95 mmHg in patients without diabetes and complications of hypertension, and 140/80 mmHg in patients with diabetes or a history of stroke. (3) A prospective cohort analysis confirmed the progressive nature of the relation between blood pressure and the risk of cardiovascular events: after about 12 years the incidence of cardiovascular events was 7% when blood pressure was less than 120/80 mmHg and 12% when it was between 130/85 and 140/90 mmHg. However, patients with these moderately elevated blood pressure values were also more likely to be diabetic. (4) The only trial involving patients with systolic pressure values between 130 and 139 mmHg, levels referred to by some as 'prehypertension', was not designed to determine either the clinical benefits or the adverse effects of treatment with candesartan. Two years after withdrawal of this antihypertensive drug, there was no statistically significant difference in the proportion of patients requiring antihypertensive treatment (threshold 160/100 mmHg). (5) In practice, 'prehypertension' is not a useful concept for patient management. The blood pressure thresholds above which the risk-benefit balance for some treatments becomes positive, in terms of morbidity or mortality, remain at 160/95 mmHg for patients without diabetes or complications and 140/80 mmHg for patients with diabetes or a history of stroke.