The Hypertension Optimal Treatment Study (the HOT Study).

The Hypertension Optimal Treatment (HOT) Study is a prospective, randomized, multicenter study which will be conducted in some 20 countries world-wide. Two major issues will be investigated: i) What is the optimal target diastolic blood pressure during antihypertensive treatment with regard to the reduction in cardiovascular morbidity and mortality? In order to address this question patients will be randomized to three different therapeutic goals: a diastolic blood pressure < or = 90 mmHg, < or = 85 mmHg or < or = 80 mmHg; ii) The second aim is to evaluate the effect of a low dose acetylsalicylic acid (ASA, aspirin) 75 mg o.d. in comparison with placebo on cardiovascular morbidity and mortality. The first aim will be investigated in accordance with the PROBE design (Prospective Randomized Open Blinded Endpoint evaluation), whereas the evaluation of aspirin versus placebo will be conducted under double blind conditions. It is estimated that 1,100 clinical events will be needed in order to answer the question regarding the relationship between target diastolic blood pressure and major cardiovascular events. The collection of these events will require the enrollment of at least 18,000 hypertensive men and women aged 50-80 years to be followed for 2.5 years (about 40,000 patient years). All patients will be given felodipine 5 mg o.d. as basic antihypertensive treatment with the addition of a beta-blocker or an ACE-inhibitor in a second step, with further predetermined increments in dosage as required in order to obtain the randomized therapeutic goal.