The AHA Guidelines and Scientifi c Statements Handbook
Benefi ts of lowering BP
In clinical trials, antihypertensive therapy has been
associated with 35% to 40% mean reductions in
stroke incidence; 20% to 25% in myocardial infarc-
tion; and more than 50% in heart failure [15]. It is
estimated that in patients with stage 1 hypertension
(SBP, 140–159 mm Hg and/or DBP, 90–99 mm Hg)
and additional cardiovascular risk factors, achieving
a sustained 12 mm Hg decrease in SBP for 10 years
will prevent one death for every 11 patients treated.
In the presence of cardiovascular disease or target-
organ damage, only nine patients would require this
BP reduction to prevent a death [16]. However, we
do not yet have any outcome studies of treatment of
“pre-hypertension” in individuals with blood pres-
sures in the range of 120–139/80–89 mm Hg,
although we do know from the Trial of Preventing
Hypertension (TROPHY) study [17], that treatment
of “pre-hypertension” lowers the likelihood of
developing true hypertension, even up to a year after
the cessation of treatment.
BP control rates
Hypertension is the most common primary diagno-
sis in the United States. The overall prevalence in
2003–4 was 29.6%. Only two-thirds (66.5%) of
those with hypertension were aware that they had it,
and of these only about half (53.7%) were being
treated at all. Of those on treatment 63.9% were at
goal, with a BP ≤140/90 mm Hg [10] (Table 11.2).
Simple arithmetic tells us that only about 20% of
individuals with hypertension are adequately treated
to goal BP. If we were to factor in the even lower BP
goals for individuals with diabetes, chronic kidney
disease, coronary artery disease and high-risk for
cardiovascular disease, the picture is even more
dismal. These current control rates are far below the
Healthy People 2010 goal of 50%. Recent clinical
trials have demonstrated that effective BP control
can be achieved in most patients with hypertension,
but the majority will require two or more antihyper-
tensive drugs [18].Blood pressure measurement in the clinic
or the offi ce
In 2005 the AHA published “Recommendations for
Blood Pressure Measurement in Humans and
Experimental Animals. Part 1: Blood Pressure Mea-
surement in Humans, a Statement from the Sub-
committee of Professional and Public Education of
the American Heart Association Council on High
Blood Pressure Research” [3]. The following are
extracts from that report.Table 11.1 Classifi cation of blood pressure for adults
BP classifi cation Systolic BP Diastolic BP
Normal < 120 and < 80
Prehypertension 120–139 or 80–89
Stage 1 hypertension 140–159 or 90–99
Stage 2 hypertension ≥ 160 or ≥ 100
Modifi ed, with permission, from Chobanian, et al. (2003) [1].
Table 11.2 Awareness, treatment and control among individuals with hypertension in the US propulation – NHANES 1999–2004
Prevalence (%) Awareness (%) Treatment (%) Control (treated) (%)1999–2000 28.6 63.0 47.3 51.3
2001–2002 27.9 62.5 50.1 63.9
2003–2004 29.6 66.5 53.7 63.9
NHANES: National Health and Nutrition Examination Survey.
Date are age adjusted. Hypertension was defi ned as average BP of 2 : 140/90 mm Hg or if the individual was taking prescribed antihypertensive medication. “Aware-
ness” refers to those individuals identifi ed as hypertensive and who were aware of the diagnosis, “Treatment” is the percentage of those who were aware that they
were hypertensive and who were on antihypertensive medication, and “Control” indicates the percentage of those treated whose BP was <140/90 mm Hg. Adapted,
with permission, from Ong, et al. (2004) [10].