352 Coronary Heart Disease and Hypertension
Figure 15.4 Cumulative time-to-event curves for exercise, stress manage-
ment, and usual care groups. After adjusting for age, baseline left ventricular
ejection fraction, and history of myocardial infarction, stress management
was associated with a signi“cantly lower risk of an adverse cardiac event
compared with usual care. Exercise was also associated with a lower relative
risk compared with usual care, but this difference was not statistically
signi“cant. The asterisk indicates signi“cantly dif ferent from usual care at
P< .05. Source:Reprinted with permission from Blumenthal et al. (1997).
Archives of Internal Medicine, 157,2213...2223.
Summary
Evidence has shown that there are several promising behav-
ioral and psychosocial interventions to aid in the treatment
and prevention of coronary disease in high-risk individuals.
Those described included: cognitive-behavioral interventions
directed at lessening and hostility and Type A behavior
(RCPP); a tailored program (Ischemic Heart Disease Life
Stress Monitoring Program), which provided social support
and counseling aimed at reducing life stress; a lifestyle-
modi“cation program consisting of a low-fat vegetarian diet,
group and individual stress management training, smoking
cessation, and moderate levels of aerobic exercise (Lifestyle
Heart Trial); and a long-term follow-up study of over 85,000
women which con“rmed beliefs that lifestyle choices in”u-
ence cardiac health. Meta-analyzes of 2,024 patients who re-
ceived psychosocial treatment and 1,156 control subjects
demonstrated that treatment group showed greater reductions
in psychological distress, systolic blood pressure, heart rate,
and cholesterol levels, while the control subjects showed
greater mortality and cardiac recurrences during a two-year
follow-up (Linden, Stossel, & Maurice, 1996). The data
in this area suggest that it is vital to include psychosocial
treatment components in cardiac rehabilitation, and that it is
essential to identify the most effective and speci“c type of
psychosocial treatment for each individual. Rozanski et al.
(1999) have summarized the impact of various psychosocial
intervention trials on cardiac events (Table 15.2).HYPERTENSIONEssential hypertension, also called primary or idiopathic hy-
pertension, is de“ned as persistent elevated blood pressure,
systolic pressure greater that 140 mm Hg and diastolic
greater than 90 mm Hg, in which there is no single identi“-
able cause. It is a serious condition because of the burden it
places on the body•s organs and vascular system. There is a
strong positive correlation between elevated blood pressure
and stroke, renal failure, and heart failure. Additionally, it is
the single most important risk factor for CHD (Cutler, 1996).
Essential hypertension accounts for 95% of all hypertension
cases. It is estimated that 24% of the adult population in
the United States is hypertensive or is taking hypertensive
medications (Carretero & Oparil, 2000a). This proportion
changes with ethnicity, gender, age, and socioeconomic sta-
tus. The percentage of African Americans with hypertension
is the highest in the world. Additionally, they develop hyper-
tension at an earlier age creating greater complications
from the disease (Klag et al., 1997). American Indians and
Hispanics have the same or lower rates than non-Hispanic
Whites (Hall et al., 1997). More men than women have
hypertension until menopause, when the numbers become
equal and blood pressure rises with age, creating a greater
prevalence in the elderly. Socioeconomic status, frequently
an indicator of lifestyle attributes, is inversely related to the
prevalence of hypertension (Carretero & Oparil, 2000a). The
National Health and Nutrition Examination Survey
(NHANES III) found that despite an increase in awareness
from 51% in the 1970s to 73% in the 1990s and an increase
in the number of people being treated for hypertension, the
rate of those with controlled hypertension has notimproved.
Furthermore, the rates of complications from hypertension
have risen (Burt et al., 1995).Genetic and Environmental InteractionsAmong the known factors that increase blood pressure are
genetics, obesity, high alcohol intake, aging, sedentary
lifestyle, stress, high sodium intake, and low intake of cal-
cium and potassium (INTERSALT CO-operative Research
Group, 1988; Severs & Poutler, 1989). Thus, essential hyper-
tension appears to be caused by an interaction between genes
and an environment that includes one or more or these risk
factors. Research involving animal subjects and human twin
subjects has shown a genetic link. It has proven that blood[Image not available in this electronic edition.]