CORRELATION BETWEEN BLOOD PRESSURE AND RISK OF CARDIOVASCULAR EVENTS: The goal of antihypertensive treatment is to reduce morbidity and mortality from cardiovascular disease associated with high blood pressure values. Epidemiological studies have demonstrated a direct correlation between the risk of stroke or coronary events and blood pressure values, and randomized controlled trials with antihypertensive drugs have shown that an average fall in diastolic blood pressure (DBP) of 5-6 mmHg [or in systolic blood pressure (SBP) of 10 mmHg] reduces the relative risk of cerebrovascular events by 40% and of coronary events by 15%. Thus, it would seem appropriate to achieve the maximum tolerated blood pressure reduction, although there is still no consensus on how far blood pressure should be lowered. PROBLEMS OF BLOOD PRESSURE CONTROL: Because the reduction in the absolute risk for a given level of blood pressure is higher in elderly patients and in those with multiple risk factors, the 1996 World Health Organization report recommends lowering blood pressure to below 140/90 mmHg in elderly patients, and suggests that it might be desirable to achieve blood pressure values of 120-130/80 mmHg in young patients with mild hypertension. Recent surveys in primary care centers in Spain show blood pressure control rates (blood pressure < 140/90 mmHg) ranging from 13 to 26%. These insufficient rates denote the particular difficulty of controlling SBP in an elderly population of patients with essential hypertension mainly treated in monotherapy schedules. The picture is similar in other developed countries. In a sample of 14,000 patients from Western European countries the Cardiomonitor survey showed control rates of 43% for DBP (< 90 mmHg) and 35% for SBP (< 140 mmHg). No more than 24% of treated hypertensive patients achieve the target (blood pressure < 140/90 mmHg) in the USA, and no more than 27% (DBP < 90 mmHg) in New Zealand. Preliminary reports from the Hypertension Optimal Treatment study indicate that in most patients combined therapy is required to achieve target blood pressure. Fixed combinations of synergistic antihypertensive drugs may help to improve both drug compliance and blood pressure control.