Coronary Heart Disease 3510 1 2 3 4 5Change in Percentage Diameter Stenosis(After...Before Intervention)Most Adherence Medium Adherence
(a) Experimental Study GroupLeast Adherence0 2 4 6Change in Percentage Diameter Stenosis(After...Before Intervention)Most Adherence Medium Adherence
(b) Whole Study GroupLeast Adherence2468Figure 15.3 Disease regression measured in the (a) experimental study
group and (b) whole study group by Ornish et al. Reprinted with permission
from Ornish et al. (1990). Lancet, 336,129...133.
After such encouraging “ndings, Ornish and colleagues
extended the study follow-up for four additional years to
determine whether participants could adhere to the inten-
sive lifestyle changes and to assess what impact this adher-
ence might have on their disease status (Ornish et al., 1998).
The researchers found that on average there was more reduc-
tion and continued improvement after “ve years than after
just one year in the intervention patients. However, control
group patients showed a continued progression in average
percent diameter stenosis over the “ve years despite the fact
that over half of them were prescribed lipid-lowering medica-
tions throughout that period. None of the lifestyle change
group was prescribed lipid-lowering medications, yet on av-
erage, they showed better results than even those in the con-
trol group who were taking the medications. The possible
additional bene“ts these medications might have conferred
on the experimental group had they been taken are unknown.
The control group experienced twice as many cardiac events
per patient as the intervention group did. In addition, the
researchers again found that there was a dose-response
relationship between adherence to the lifestyle change pro-
gram and reduction in percent diameter stenosis in coronary
arteries.
Another important long-term lifestyle study is the Nurses•
Health Study, which followed 85,941 healthy women (no
cardiovascular disease or cancer) from 1980 through 1994,
monitoring their medical history, lifestyle variables including
smoking and diet, and disease development of any kind (Hu,
Stampfer, Manson, et al., 2000). These observations were
then used to determine what effect lifestyle and other risk
factors had on the incidence of CHD. The study found that
coronary disease declined by 31% from the two-year period
1980 to 1982 to the two-year period 1992 to 1994. Smoking
also declined by 41% from 1980 to 1992, and there was a
175% increase in the use of hormone therapy for post-
menopausal women. These variables combined to explain a
21% decline in the incidence of coronary disease over the du-
ration of the study. It was also found that 3% of the study
population who had none of the biggest risk factors (smok-
ing, overweight, lack of exercise, and poor diet) had an 83%
lower risk of coronary events than the rest of the women
(Stampfer et al., 2000). Overall, 82% of coronary events in
the study could be attributed to lack of adherence to a low-
risk lifestyle as de“ned in the study.
Blumenthal and colleagues examined the extent to which
mental-stress induced ischemia could be modi“ed by exer-
cise stress management and evaluated the impact of these in-
terventions on clinical outcomes. A group of 107 patients
with CAD and documented ischemia during either mental
stress or ambulatory electrocardiographic monitoring were
randomly assigned to a stress management group, an exercise
training group, or a normal care control group and titrated
from anti-ischemic medications. Myocardial ischemia was
reassessed following four months of participation and pa-
tients were contacted for up to “ve years to document subse-
quent cardiac events. It was found that the stress management
group had the lowest risk of experiencing a cardiac event dur-
ing follow-up, followed by the exercise group, and then the
control group. In addition, stress management was also asso-
ciated with reduced ischemia induced by laboratory mental
stress. These data reinforce the notion that behavioral inter-
ventions offer additional bene“t above and beyond usual car-
diac care in patients with documented myocardial ischemia
(Figure 15.4) (Blumenthal et al., 1997).