Although pharmacological treatment of hypertension has important health benefits, it does not capture the benefit of maintenance of ideal health through the prevention or delay of hypertension. Therefore, Dr. George Howard, professor in the department of biostatistics at the University of Alabama at Birmingham, and colleagues assessed and followed a total of 26,875 Black and White participants ages 45 years and older for incident stroke events in order to assess the increased risk of “optimally” treating hypertension after it develops compared with preventing hypertension from developing in the first place. UAB co-investigators are Dr. Virginia J. Howard, professor, and Dr. Paul Muntner, professor and vice chair, in the department of epidemiology; and Dr. Suzanne Oparil, professor in the division of cardiovascular disease.
The association was evaluated between incident stroke and: 1) systolic blood pressure (SBP) categorized as normal (less than 120 mm Hg), prehypertension (120 to 139 mm Hg), stage 1 hypertension (140 to 159 mm Hg), and stage 2 hypertension (over 160 mm Hg); and 2) the number of classes of antihypertensive medications, classified as none, 1, 2, or 3 or more. During 6.3 years of follow-up, 823 stroke events occurred. Nearly half (46 percent) of the population were hypertensive subjects successfully treated to guideline goals (SBP less than 140 mm Hg). However, for those in the normotensive strata (SBP less than 120 mm Hg), compared with those who never developed hypertension, the stroke risk increased 33 percent for each additional blood pressure medication required to control blood pressure. Similar increases of 15 percent and 22 percent were seen for each medication required to control the blood pressure for those in the prehypertension strata (120 to 139 mm Hg) and stage 1 hypertension strata (140 to 159 mm Hg) A successfully treated (SBP less than 120 mm Hg) hypertensive person on over 3 antihypertensive medication classes was at marginally higher stroke risk than a person with untreated stage 1 hypertension (HR 2.48 versus HR=2.19, relative to those with SBP less than 120 on no antihypertensive medications).
While maintaining blood pressure at levels meeting guidelines through pharmacological treatment substantially reduces risk, it fails to return these hypertensive individuals to a risk level similar to those who never developed hypertension. The researchers concluded that even with successful treatment there is a substantial potential gain by prevention or delay of hypertension for the approximate one-half of the population ages 45 and over who achieve good control of their blood pressure.
“Is Blood Pressure Control for Stroke Prevention the Correct Goal? The Lost Opportunity of Preventing Hypertension” was published online in the May 7 issue of the journal Stroke.