Lowering blood pressure. How far, how fast?

There is a general consensus that high blood pressure (BP) must be lowered gradually. A reduction in BP beyond the limits of the autoregulatory curve may compromise perfusion of vital organs, resulting in organ ischaemia. However, a reduction in high BP offers protection against cerebral events, and some protection against coronary heart disease. The limited protection against coronary heart disease provided by BP reduction may be partially explained by the so-called 'J-shaped curve': a reduction in diastolic blood pressure below 85 mmHg may lead to a paradoxical increase in coronary events, although this effect is by no means well established. In addition, the incidence of several events associated with cardiovascular disease peaks during morning hours, at a time when some antihypertensive drugs are least effective. This may also explain the limited coronary protection achieved after administration of antihypertensive drugs.