The BBB Study: the effect of intensified antihypertensive treatment on the level of blood pressure, side-effects, morbidity and mortality in "well-treated" hypertensive patients. Behandla Blodtryck Bättre.

The BBB study (Swedish for Behandla Blodtryck Bättre or Treat Blood Pressure Better) was a multicenter trial designed to investigate three aspects of antihypertensive treatment: i) Is it possible to lower the diastolic blood pressure further in "well-treated" hypertensive patients through intensified therapy? ii) Can this aim be fulfilled without increasing the incidence or severity of side-effects? iii) If i) and ii) can be answered in the affirmative, will the further reduction in diastolic blood pressure be associated with a further reduction in hypertension-associated mortality and morbidity? Altogether 2127 hypertensive men and women with an average age of 59.8 years (46-71) were recruited at 142 primary health care centers in Sweden. Approximately 10,000 patient-years were accumulated. All patients had treated essential hypertension and all had diastolic blood pressures in the range 90-100 mmHg on three consecutive visits before entering the study. The patients were randomized to either intensified treatment aiming at a blood pressure < or = 80 mmHg diastolic (group A) or to unchanged therapy (group B). A difference between group A and group B in diastolic blood pressure of 7-7.5 mmHg was achieved for > 4 years. Adverse effects were studied in detail in 100 randomly selected patients from each group using a special questionnaire and a visual analogue scale. The adverse effect score fell significantly in group A but remained unchanged in group B. Regarding cardiovascular morbidity and mortality there were no significant differences between groups A and B, the total number of strokes and myocardial infarcts being 28 in group A and 29 in group B.(ABSTRACT TRUNCATED AT 250 WORDS)