The effects of awareness, treatment and control of hypertension on future stroke incidence in a community-based population study in Finland

Objective To investigate whether there are differences in stroke risk among hypertensive men and women by awareness, treatment and blood pressure control status at baseline. Methods This was a prospective study with a median follow-up of 20 years including 22 836 men and 24 774 women aged 25–64 years. The participants were classified into five groups according to their blood pressure status. Mortality data were obtained from Statistics Finland and data on nonfatal events from the National Hospital discharge register. Results The risk of stroke was significantly increased in men and women in all hypertensive groups compared with normotensive people. Hypertensive and treated men [hazard ratio 1.35; 95% confidence interval (CI) 1.02–1.80] and women (hazard ratio 1.87; 95% CI 1.50–2.32) had a statistically significantly higher risk of total stroke than normotensive people despite baseline blood pressure control. Whereas the hazard ratio for incident ischemic stroke was 1.85 (95% CI 1.46–2.35) for the hypertensive, treated, controlled women, men with their hypertension treated and controlled did not have a statistically significantly increased risk of ischemic stroke (hazard ratio 1.30; 95% CI 0.94–1.78) compared with the reference group. Conclusion The risk of stroke increased in hypertensive people. Despite antihypertensive drug treatment and adequate control of hypertension, the risk of stroke remained relatively high. This stresses the importance of adequate primary prevention and more effective early management of hypertension.