The AHA Guidelines and Scientific Statements Handbook

The AHA Guidelines and Scientifi c Statements Handbook

Age at Risk (y)

Stroke mortality rate in each decade of age versus usual

blood pressure at the start of that decade

Cl) 128

256

SBP DBP

70 79

80-89

Age

256

128

talityk and 95%^32

64

128

60-69

(^128) 70-79
64
32
8
16
roke mortbsolute risk
16 50-59
8
2
St 4
floating ab
4
2
(f 1
120 140 160 180 70 80 90 100 110
1
Usual SBP (mmHg) Usual DBP (mmHg)
Fig. 11.2 Stroke mortality rate in each decade of age versus usual blood pressure at the start of that decade. Reprinted with permission from
Lewington et al. Lancet. 2002;360:1903–1913.
stolic increase in BP, there is a doubling of mortality
from both ischemic heart disease and stroke (Figs
11.1 and 11.2). In addition, longitudinal data
obtained from the Framingham Heart Study [12]
have indicated that BP values in the 130 to 139/85
to 89 mm Hg range previously considered to be
normal but now within the “pre-hypertension” cat-
egory, are associated with a more than 2-fold increase
in relative risk from cardiovascular disease (CVD)
compared with those with BP levels below
120/80 mm Hg (Fig. 11.3).
BP changes with increasing age. The rise in SBP
continues throughout life, in contrast to DBP, which
rises until approximately 50 years old, tends to level
off over the next decade, and may remain the same
or fall later in life [13] (Fig. 11.4). Diastolic hyper-
tension predominates before 50 years of age, either
alone or in combination with SBP elevation. The
prevalence of systolic hypertension increases with
age, and above the age of 50 years, systolic hyperten-
sion represents the most common form of hyperten-
sion. DBP is a more potent cardiovascular risk factor
than SBP until age 50; thereafter, SBP is more
important [14].
Table 11.1 is the JNC 7 classifi cation of BP for
adults aged 18 years or older. JNC 7 suggests that all
people with hypertension (Stages 1 and 2) be treated.
At present the treatment goal for BP in individuals
with hypertension and no other compelling condi-
tions is <140/90 mm Hg, but is <130/80 mm Hg for
patients with diabetes, kidney disease, coronary
artery disease, and those with a Framingham 10-year
risk score of ≥10%. The goal for individuals with
uncomplicated pre-hypertension (120–139/80–
89 mm Hg) with no compelling indications for phar-
macologic therapy is to lower BP to normal with
lifestyle changes and prevent the progressive rise in
BP using the recommended lifestyle modifi cations.