Survival of hypertensive subjects identified on screening: results for sustained and unsustained diastolic hypertension.

Casual readings of blood pressure predict mortality and may reflect either the risk of sustained hypertension, additional components of 'white coat' hypertension or variable blood pressure. This study investigated mortality in 442 men and 360 women with a diastolic pressure (Phase IV) of 90 mmHg and over, unsustained on two subsequent monthly visits, followed for an average of 11 years and compared with a matched control cohort with an initial diastolic pressure (DBP) of less than 90 mmHg. Subjects were identified between 1975 and 1979 by screening 28,257 subjects aged 18-65 years on the lists of general practitioners in seven practices in the United Kingdom. Additionally, 912 men and 844 women with sustained hypertension (DBP > 90 mmHg on at least two out of three occasions) were identified and matched with normotensive controls. In men with sustained hypertension the relative risk (RR) for death from circulatory disease was 1.76, P < 0.01, 95% confidence interval 1.21, 2.58 and in women 1.85, P < 0.05, 95% confidence interval 1.06, 3.24 respectively, while in men with unsustained hypertension the RR = 1.52, P = 0.2, 95% confidence interval 0.81, 2.84. Few circulatory deaths occurred in women with transient hypertension or their controls (five and seven respectively). Despite the screening programme and further treatment, newly discovered subjects with sustained hypertension, both men and women, remain at high risk of cardiovascular mortality. The 95% confidence interval for men with transient hypertension does not exclude a similar adverse effect.