Antihypertensive drug treatment: the potential, expected and observed effects on vascular disease

Re-analysis of the results of several prospective observational studies indicates that modest long-term differences in usual diastolic blood pressure are associated with larger differences in the primary incidence of stroke and of coronary heart disease than was previously believed. A prolonged difference of 5-6 mmHg in usual diastolic blood pressure was associated with at least one-third fewer strokes and at least one-fifth fewer coronary heart disease events. The results of randomly allocated trials of antihypertensive drug therapy (mostly diuretics) indicate that a similar difference in diastolic blood pressure maintained for just a few years appears to produce much or all of the potential long-term benefits for stroke. The incidence of coronary heart disease was also significantly reduced by treatment (2P < 0.01). However, for coronary disease, the trial results, even in combination, are inadequate to allow a reliable determination of the size of the treatment effects and the proportion of the long-term potential benefit achieved by a few years of diuretic-based treatment.