Section 2. Recommendations for Adults (Continued)
Heart and Vascular Diseases
Screening for Abdominal Aortic Aneurysm
Summary of Recommendations
The U.S. Preventive Services Task Force
(USPSTF) recommends one-time screening for
abdominal aortic aneurysm (AAA) by
ultrasonography in men aged 65 to 75 who have
ever smoked.
Rating: B Recommendation.
The USPSTF makes no recommendation for or
against screening for AAA in men aged 65 to 75
who have never smoked.
Rating: C Recommendation.
The USPSTF recommends against routine
screening for AAA in women.
Rating: D Recommendation.
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This USPSTF recommendation was first published in: Ann Intern Med. 2005;142:198-202. http://www.ahrq.gov/clinic/uspstf05/aaascr/aaars.htm.
Clinical Considerations
- The major risk factors for abdominal aortic
aneurysm (AAA) include age (being 65 or older),
male sex, and a history of ever smoking (at least 100
cigarettes in a person's lifetime). A first-degree
family history of AAA requiring surgical repair also
elevates a man's risk for AAA; this may also be true
for women but the evidence is less certain. There is
only a modest association between risk factors for
atherosclerotic disease and AAA.
- Screening for AAA would most benefit those who
have a reasonably high probability of having an
AAA large enough, or that will become large
enough, to benefit from surgery. In general, adults
younger than age 65 and adults of any age who
have never smoked are at low risk for AAA and are
not likely to benefit from screening. Among men
aged 65 to 74, an estimated 500 who have ever
smoked—or 1,783 who have never smoked—would
need to be screened to prevent 1 AAA-related death
in the next 5 years. As always, clinicians must
individualize recommendations depending on a
patient's risk and likelihood of benefit. For example,
some clinicians may choose to discuss screening
with male nonsmokers nearing age 65 who have a
strong first-degree family history of AAA that
required surgery.
- The potential benefit of screening for AAA among
women aged 65 to 75 is low because of the small
number of AAA-related deaths in this population.
The majority of deaths from AAA rupture occur in
women aged 80 or older. Because there are many
competing health risks at this age, any benefit of
screening for AAA would be minimal.
Individualization of care, however, is still required.
For example, a clinician may choose to discuss
screening in the unusual circumstance in which a
healthy female smoker in her early 70s has a first-degree
family history for AAA that required surgery.
- Operative mortality for open surgical repair of an
AAA is 4 to 5 percent, and nearly one-third of patients undergoing this surgery have other
important complications (e.g., cardiac and
pulmonary). Additionally, men having this surgery
are at increased risk for impotence.
- Endovascular repair of AAAs (EVAR) is currently
being used as an alternative to open surgical repair.
Although recent studies have shown a short-term
mortality and morbidity benefit of EVAR compared
with open surgical repair, the long-term
effectiveness of EVAR to reduce AAA rupture and
mortality is unknown. The long-term harms of
EVAR include late conversion to open repair and
aneurysmal rupture. EVAR performed with older-generation
devices is reported to have an annual rate
of rupture of 1 percent and conversion to open
surgical repair of 2 percent. The conversion to open
surgical repair is associated with a peri-operative
mortality of about 24 percent. The long-term harms
of newer generation EVAR devices are yet to be
reported.
- For most men, 75 years may be considered an
upper age limit for screening. Patients cannot
benefit from screening and subsequent surgery
unless they have a reasonable life expectancy. The
increased presence of comorbidities for people aged
75 and older decreases the likelihood that they will
benefit from screening.
- Ultrasonography has a sensitivity of 95 percent and
specificity of nearly 100 percent when performed in
a setting with adequate quality assurance. The
absence of quality assurance is likely to lower test accuracy. Abdominal palpation has poor accuracy
and is not an adequate screening test.
- One-time screening to detect an AAA using
ultrasonography is sufficient. There is negligible
health benefit in re-screening those who have
normal aortic diameter on initial screening.
- Open surgical repair for an AAA of at least 5.5 cm
leads to an estimated 43-percent reduction in AAA-specific
mortality in older men who undergo
screening. However, there is no current evidence
that screening reduces all-cause mortality in this
population.
- In men with intermediate-sized AAAs (4.0-5.4 cm),
periodic surveillance offers comparable mortality
benefit to routine elective surgery with the benefit
of fewer operations. Although there is no evidence
to support the effectiveness of any intervention in
those with small AAAs (3.0-3.9 cm), there are
expert opinion-based recommendations in favor of
periodic repeat ultrasonography for these patients.
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Aspirin for the Primary Prevention of Cardiovascular Events
Summary of Recommendation
The U.S. Preventive Services Task Force
(USPSTF) strongly recommends that clinicians
discuss aspirin chemoprevention with adults who
are at increased risk for coronary heart disease
(CHD). Discussions with patients should address
both the potential benefits and harms of aspirin
therapy. Rating: A Recommendation.
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This USPSTF recommendation was first published in: Ann Intern Med 2002;136(2):157-60. http://www.ahrq.gov/clinic/3rduspstf/aspirin/asprr.htm.
Clinical Considerations
- Decisions about aspirin therapy should take into
account overall risk for coronary heart disease. Risk
assessment should include asking about the presence
and severity of the following risk factors: age, sex,
diabetes, elevated total cholesterol levels, low levels of
high-density lipoprotein (HDL) cholesterol, elevated
blood pressure, family history (in younger adults),
and smoking. Tools that incorporate specific
information on multiple risk factors provide more
accurate estimation of cardiovascular risk than
categorizations based simply on counting the
numbers of risk factors (www.intmed.mcw.edu/clincalc/heartrisk.html).16
- Men older than 40 years, postmenopausal women, and younger people with risk factors for CHD (e.g., hypertension, diabetes, or smoking) are at increased risk for heart disease and may wish to consider aspirin therapy. Table 2 shows how estimates of the type and magnitude of benefits and harms associated with aspirin therapy vary with an individual's underlying risk for coronary heart disease. Although balance of benefits and harms is most favorable in high-risk people (5-year risk > 3 percent), some people at lower risk may consider the potential benefits of aspirin to be sufficient to outweigh the potential harms.
- Discussions about aspirin therapy should focus on
potential coronary heart disease benefits, such as
prevention of myocardial infarction, and potential
harms, such as gastrointestinal and intracranial
bleeding. Discussions should take into account
individual preferences and risk aversions concerning
myocardial infarction, stroke, and gastrointestinal
bleeding.
- Although the optimal timing and frequency of
discussions related to aspirin therapy are unknown,
reasonable options include every 5 years in middle-aged
and older people or when other cardiovascular
risk factors are detected.
- Most participants in the primary prevention trials of
aspirin therapy have been men between 40 and 75
years of age. Current estimates of benefits and
harms may not be as reliable for women and older
men.
- Although older patients may derive greater benefits
because they are at higher risk for CHD and stroke,
their risk for bleeding may be higher.
- Uncontrolled hypertension may attenuate the
benefits of aspirin in reducing CHD.
- The optimum dose of aspirin for chemoprevention
is not known. Primary and secondary prevention
trials have demonstrated benefits with a variety of
regimens, including 75 mg per day, 100 mg per day,
and 325 mg every other day. Doses of
approximately 75 mg per day appear as effective as
higher doses; whether doses below 75 mg per day
are effective has not been established. Enteric-coated
or buffered preparations do not clearly reduce
adverse gastrointestinal effects of aspirin.
Uncontrolled hypertension and concomitant use of
other nonsteroidal anti-inflammatory agents or
anticoagulants increase risk for serious bleeding.
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Screening for Coronary Heart Disease
Summary of Recommendations
The U.S. Preventive Services Task Force
(USPSTF) recommends against routine screening
with resting electrocardiography (ECG), exercise
treadmill test (ETT), or electron-beam
computerized tomography (EBCT) scanning for
coronary calcium for either the presence of severe
coronary artery stenosis (CAS) or the prediction of
coronary heart disease (CHD) events in adults at
low risk for CHD events. Rating: D
Recommendation.
The USPSTF found insufficient evidence to
recommend for or against routine screening with
ECG, ETT, or EBCT scanning for coronary
calcium for either the presence of severe CAS or
the prediction of CHD events in adults at
increased risk for CHD events. Rating: I
Recommendation.
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This USPSTF recommendation was first published in: Ann Intern Med 2004;140:569-72. http://www.ahrq.gov/clinic/3rduspstf/chd/chdrs.htm.
Clinical Considerations
- Several factors are associated with a higher risk for CHD events (the major
ones are nonfatal myocardial infarction and coronary death), including older
age, male gender, high blood pressure, smoking, abnormal lipid levels, diabetes,
obesity, and sedentary lifestyle. A person's risk for CHD events can be estimated
based on the presence of these factors. Calculators are available to ascertain
a person's risk for having a CHD event; for example, a calculator to estimate
a person's risk for a CHD event in the next 10 years can be accessed at http://hin.nhlbi.nih.gov/atpiii/calculator.asp?usertype=prof. Although the exact risk factors that constitute each of these categories (low or increased risk) have not been established,
younger adults (i.e., men < 50 years and women < 60 years) who have no
other risk factors for CHD (< 5 percent-10 percent 10-year risk) are considered to be
at low risk. Older adults, or younger adults with 1 or more risk factors (>
15 percent-20 percent 10-year risk), are considered to be at increased risk.
- Screening with ECG, ETT, and EBCT could potentially reduce CHD events in
2 ways: either by detecting people at high risk for CHD events who could benefit
from more aggressive risk factor modification, or by detecting people with
existing severe CAS whose life could be prolonged by coronary artery bypass
grafting (CABG) surgery. However, the evidence is inadequate to determine
the extent to which people detected through screening in either situation
would benefit from either type of intervention.
- The consequences of false-positive tests may potentially outweigh the benefits
of screening. False-positive tests are common among asymptomatic adults, especially
women, and may lead to unnecessary diagnostic testing, over-treatment, and
labeling.
- Because the sensitivity of these tests is limited, screening could also
result in false-negative results. A negative test does not rule out the presence
of severe CAS or a future CHD event.
- For people in certain occupations, such as pilots and heavy equipment operators
(for whom sudden incapacitation or sudden death may endanger the safety of
others), considerations other than the health benefit to the individual patient
may influence the decision to screen for CHD.
- Although some exercise programs initially screen asymptomatic participants
with ETT, there is not enough evidence to determine the balance of benefits
and harms of this practice.
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Screening for High Blood Pressure
Summary of Recommendations
The U.S. Preventive Services Task Force
(USPSTF) strongly recommends that clinicians
screen adults aged 18 and older for high blood
pressure. Rating: A Recommendation.
The USPSTF concludes that the evidence is
insufficient to recommend for or against routine
screening for high blood pressure in children and
adolescents to reduce the risk of cardiovascular
disease. Rating: I Recommendation.
|
This USPSTF recommendation was first published by:
Agency for Healthcare Research and Quality, Rockville,
MD. July 2003. http://www.ahrq.gov/clinic/uspstf/uspshype.htm.
Clinical Considerations
- Office measurement of blood pressure is most commonly done with a sphygmomanometer.
High blood pressure (hypertension) is usually defined in adults as a systolic
blood pressure (SBP) of 140 mm Hg or higher, or a diastolic blood pressure
(DBP) of 90 mm Hg or higher. Due to variability in individual blood pressure
measurements (occurring as a result of instrument, observer, and patient factors),
it is recommended that hypertension be diagnosed only after two or more elevated
readings are obtained on at least two visits over a period of one to several weeks.
- There are some data to suggest that ambulatory blood pressure measurement
(that provides a measure of the average blood pressure over 24 hours) may
be a better predictor of clinical cardiovascular outcome than clinic-based
approaches; however, ambulatory blood pressure measurement is subject to many
of the same errors as office blood pressure measurement.
- The relationship between SBP and DBP and cardiovascular risk is continuous
and graded. The actual level of blood pressure elevation should not be the
sole factor in determining treatment. Clinicians should consider the patient's
overall cardiovascular risk profile, including smoking, diabetes, abnormal
blood lipids, age, sex, sedentary lifestyle, and obesity, in making treatment
decisions.
- Hypertension in children has been defined as blood pressure above the 95th
percentile for age, sex, and height. Up to 28 percent of children have secondary
hypertension, i.e., high blood pressure due to causes such as coarctation of
the aorta, renal parenchymal disease, renal artery stenosis, and other congenital
malformations. On the basis of expert opinion, several organizations, including
the American Academy of Pediatrics (AAP), American Heart Association (AHA),
and American Medical Association (AMA), recommend routine screening of asymptomatic
adolescents and children during preventive care visits, based on the potential
for identifying treatable causes of secondary hypertension, such as coarctation
of aorta. However, there are limited data on the benefits or risks of screening
and treating such underlying causes of hypertension in children. The decision
to screen children and adolescents for hypertension remains a matter of clinical
judgment.
- Evidence is lacking to recommend an optimal interval for screening adults
for high blood pressure. The sixth report of the Joint National Committee
on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure
(JNC 6) recommends screening every 2 years for persons with SBP and DBP below
130 mm Hg and 85 mm Hg, respectively, and more frequent intervals for screening
those with blood pressure at higher levels.
- A variety of pharmacological agents are available to treat high blood pressure.
JNC 6 guidelines for treatment of high blood pressure can be accessed at www.nhlbi.nih.gov/guidelines/hypertension/jncintro.htm.
The JNC 6-recommended goal of treatment is to achieve and maintain SBP below
140 mm Hg and DBP below 90 mm Hg, and lower if tolerated. Evidence indicates
that reducing DBP to below 80 mm Hg appears to be beneficial for patients
with hypertension and diabetes. In considering the effectiveness of treatment
for hypertension, it must be noted that a given treatment's ability to lower
blood pressure may not correspond directly to its ability to reduce cardiovascular
events.
- Nonpharmacological therapies, such as reducing dietary sodium intake, potassium
supplementation, increased physical activity, weight loss, stress management,
and reducing alcohol intake, are associated with a reduction in blood pressure,
but their impact on cardiovascular outcomes has not been studied. For those
who consume large amounts of alcohol (more than 20 drinks in a week), studies
have shown that reduced drinking decreases blood pressure. There is insufficient
evidence to recommend single or multiple interventions or to guide the clinician
in selecting among nonpharmacological therapies.
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Screening for Lipid Disorders in Adults
Summary of Recommendations
The U.S. Preventive Services Task Force
(USPSTF) strongly recommends that clinicians
routinely screen men aged 35 years and older and
women aged 45 years and older for lipid disorders
and treat abnormal lipids in people who are at
increased risk for coronary heart disease. Rating: A
Recommendation.
The USPSTF recommends that clinicians
routinely screen younger adults (men aged 20 to 35
years and women aged 20 to 45 years) for lipid
disorders if they have other risk factors for coronary
heart disease. (See Clinical Considerations for a
discussion of risk factors.) Rating: B
Recommendation.
The USPSTF makes no recommendation for or
against routine screening for lipid disorders in
younger adults (men aged 20 to 35 years or women
aged 20 to 45 years) in the absence of known risk
factors for coronary heart disease. Rating: C
Recommendation.
The USPSTF recommends that screening for
lipid disorders include measurement of total
cholesterol (TC) and high-density lipoprotein
cholesterol (HDL-C). Rating: B Recommendation.
The USPSTF concludes that the evidence is
insufficient to recommend for or against triglyceride
measurement as a part of routine screening for lipid
disorders. Rating: I Recommendation.
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This USPSTF recommendation was first published in: Am J Prev Med 2001;20(3S):73-6. http://www.ahrq.gov/clinic/ajpmsuppl/lipidrr.htm.
Clinical Considerations
- TC and HDL-C can be measured on nonfasting or fasting samples.
- Abnormal results should be confirmed by a repeated sample on a separate
occasion, and the average of both results should be used for risk assessment.
Although measuring both TC and HDL-C is more sensitive and specific for assessing
coronary heart disease risk, TC alone is an acceptable screening test if available
laboratory services cannot provide reliable measurements of HDL. In conjunction
with HDL-C, low-density lipoprotein cholesterol (LDLC) and TC provide comparable
information, but measuring LDL-C requires a fasting sample and is more expensive.
In patients with elevated risk on screening results, lipoprotein analysis,
including fasting triglycerides, may provide information that is useful in
choosing optimal treatments.
- Screening is recommended for men aged 20 to 35 years and for women aged
20 to 45 years in the presence of any of the following:
- Diabetes
- A family history of cardiovascular disease before age 50 years in male
relatives or age 60 years in female relatives.
- A family history suggestive of familial hyperlipidemia.
- Multiple coronary heart disease risk factors (e.g., tobacco use, hypertension).
- The optimal interval for screening is uncertain. On the basis of other guidelines
and expert opinion, reasonable options include every 5 years, shorter intervals
for people who have lipid levels close to those warranting therapy, and longer
intervals for low-risk people who have had low or repeatedly normal lipid
levels.
- An age to stop screening is not established. Screening may be appropriate
in older people who have never been screened, but repeated screening is less
important in older people because lipid levels are less likely to increase
after age 65 years.
- Treatment decisions should take into account overall risk of heart disease
rather than lipid levels alone. Overall risk assessment should include the
presence and severity of the following risk factors: age, gender, diabetes,
elevated blood pressure, family history (in younger adults), and smoking.
Tools that incorporate specific information on multiple risk factors provide
more accurate estimation of cardiovascular risk than categorizations based
on counting the numbers of risk factors.16,17
- Treatment choices should take into account costs and patient preferences.
Drug therapy is usually more effective than diet alone, but choice of treatment
should consider overall risk, costs of treatment, and patient preferences.
Guidelines for treating high cholesterol are available from the National Cholesterol
Education Program of the National Institutes of Health.18
Although diet therapy is an appropriate initial therapy for most patients,
a minority achieve substantial reductions in lipid levels from diet alone;
drugs are frequently needed to achieve therapeutic goals, especially for high-risk
people. Lipid-lowering treatments should be accompanied by interventions addressing
all modifiable risk factors for heart disease, including smoking cessation,
treatment of blood pressure, diabetes, and obesity, as well as promotion of
a healthy diet and regular physical activity. Long-term adherence to therapies
should be emphasized.
- All patients, regardless of lipid levels, should be offered counseling about
the benefits of a diet low in saturated fat and high in fruits and vegetables,
regular physical activity, avoiding tobacco use, and maintaining a healthy
weight.
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Screening for Peripheral Arterial Disease
Summary of Recommendation
The U.S. Preventive Services Task Force
(USPSTF) recommends against routine screening
for peripheral arterial disease (PAD).
Rating: D Recommendation.
|
This recommendation statement was first published by:
Agency for Healthcare Research and Quality, Rockville,
MD. August 2005. http://www.ahrq.gov/clinic/uspstf05/pad/padrs.htm.
Clinical Considerations
- The ankle brachial index, a ratio of Dopplerrecorded
systolic pressures in the lower and upper
extremities, is a simple and accurate noninvasive
test for the screening and diagnosis of PAD. The
ankle brachial index has demonstrated better
accuracy than other methods of screening,
including history-taking, questionnaires, and
palpation of peripheral pulses. An ankle-brachial
index value of less than 0.90 (95% sensitive and
specific for angiographic PAD) is strongly
associated with limitations in lower extremity
functioning and physical activity tolerance.
- Smoking cessation and lipid-lowering agents
improve claudication symptoms and lower
extremity functioning among patients with
symptomatic PAD. Smoking cessation and
physical activity training also increase maximal
walking distance among men with early PAD.
Counseling for smoking cessation, however,
should be offered to all patients who smoke,
regardless of the presence of PAD. Similarly,
physically inactive patients should be counseled to
increase their physical activity, regardless of the
presence of PAD.
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