Background: Hypertension is related to significant morbidity and mortality rates from coronary heart disease (CHD). This report examines the relative and absolute impact on risk for CHD by controlling hypertension to high normal and optimal levels.
Methods: Among all subjects with untreated or inadequately treated hypertension in the National Health and Nutrition Examination Survey (NHANES) III who were 30 to 74 years of age and without prior CHD, the 10-year risk of CHD was calculated. With the use of sampling weights, the number of CHD events by age group, hypertension subtype (isolated diastolic hypertension [IDH], systolic-diastolic hypertension [SDH], and isolated systolic hypertension [ISH]), and stage of hypertension was estimated. Risk was recalculated and the number of events reestimated, assuming a reduction in blood pressure (BP) to high normal and optimal levels. The number and proportion (population-attributable risk, or PAR%) of events that could be prevented were determined from the differences in events and risk between uncontrolled and controlled BP levels. Derived from this was the number of persons needing treatment per CHD event prevented.
Results: Control of hypertension to high normal levels could prevent approximately one fifth (PAR = 19%) of CHD events in men and one third (PAR = 31%) of CHD events in women, whereas control to optimal levels may prevent 37% and 56% of CHD events, respectively (P <.01 for differences between men and women). Of CHD events that could be prevented, the greatest proportion occurred from controlling BP among older persons, men, and those with stage 1 hypertension (vs stages 2 and 3) or with ISH (vs IDH or SDH). The number of persons with hypertension needing treatment to prevent one CHD event ranged from 20.5 in men to 38.6 in women when controlled to high normal BP and 10.7 in men and 21.3 in women when controlled to optimal BP.
Conclusions: The greatest impact from control of hypertension occurs in older persons, men, and those with ISH, whereas the greatest PAR% occurred in women. Optimal control of BP could prevent more than one third of CHD events in men and more than half of events in women. Greater efforts to control hypertension in these populations may have a substantial impact in preventing CHD events.