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. |