The prognostic significance of blood pressure in the elderly

Whilst recruiting for the Randomised Trial of the Treatment of Hypertension in Elderly Patients in Primary Care, 10,732 people aged 60-79 years of age (4,736 males and 5,996 females) were screened for hypertension. This constituted 78% of those eligible on the practice lists in this age range. These patients were followed up for a mean period of 2.6 years (range 0.1-11.2 years). All those leaving the practices were registered with the National Health Service Central Registry to ensure completeness of death ascertainment. 1,009 deaths were analysed and standardised mortality ratios computed for all deaths, stroke, coronary artery disease and all cardiovascular causes. Hypertensive patients included in the control group of the trial were also matched with patients found to be normotensive and their mortalities compared. Both high and low levels of SBP were associated with increased mortality producing a U-shaped curve for all deaths and J-shaped curves for cardiovascular causes. With increasing age the higher mortality associated with lower SBP became more pronounced. Similar effects were evident for DBP but in women high DBP was less dangerous than in men. Although the relative impact of hypertension declines with advancing age, the absolute impact is maintained up to the age of eighty.