Stroke and coronary heart disease in treated hypertension - a prospective cohort study over three decades

Objective. To compare cardiovascular mortality and morbidity in middle-aged hypertensive men with initially nonhypertensive men derived from the same random population sample, and to study stroke morbidity in these men in relation to cardiovascular risk factors during 25-28 years of follow-up. Design. Prospective, population-based observational study in men where the main intervention effort was directed towards treatment of hypertension in a special outpatient clinic. Subjects and methods. A total of 754 hypertensive men aged 47-55 years at screening were compared with 6740 men with normal blood pressure. The hypertensive men got stepped care treatment with either beta-blockers, thiazide diuretics, or combination treatment including vasodilating agents during the whole observational period. Data on cause-specific mortality and morbidity, and all cause mortality were obtained from patient files and the national registers on mortality and hospital admissions respectively. Main outcome measures. Baseline and change of cardiovascular risk factors during the first 15 years of follow-up and all cause mortality, and mortality and morbidity from stroke and coronary heart disease during 25-28 years. Results. Treated hypertensive men had their blood pressure reduced with 21/15 mmHg during the first 5 years of the study and mean blood pressure levels were then rather constant. A minor reduction of serum cholesterol was also observed and a significant reduction in the prevalence of smoking. Treated hypertensive men suffered a substantial increased incidence of cardiovascular complications that escalated during the latter course of the study. Their total incidence of stroke was doubled; they had 50% more myocardial infarctions (MIs); mortality from coronary heart disease was doubled and all cause mortality was increased by a third, compared with nonhypertensive. In multiple regression analysis the incidence of stroke was significantly related to smoking and diabetes at entry and in time-dependent Cox's regression analysis it was significantly related only to smoking. There was no relationship observed between achieved systolic or diastolic blood pressure and the risk of stroke or MI nor was there any relationship between the change in blood pressure and such cardiovascular complications. Conclusion. In spite of a substantial reduction of their blood pressure, treated hypertensive middle-aged men had a highly increased risk of stroke, MI and mortality from coronary heart disease compared with nonhypertensive men of similar age. The increased risk of cardiovascular complications escalated during the latter course of the study.