Patient Population Under Consideration
This recommendation applies to adult men and women without symptoms of heart disease or a diagnosis of
cardiovascular disease (CVD). In this recommendation, CHD refers to coronary artery disease and ischemic heart
disease.
Assessment of Risk
Accurate identification of persons at high risk for CHD events, particularly nonfatal MI and CHD death, provides the
opportunity to intensify risk factor management to reduce the likelihood of one of these events. In addition,
identifying people at low risk may allow for a reduction in interventions with a low benefit-to-risk ratio in this
risk stratum. Several factors are associated with higher risk for CHD events, including older age, male sex, high
blood pressure, smoking, abnormal lipid levels, diabetes, obesity, and sedentary lifestyle.
Risk factors can be combined in many ways to allow classification of a person's risk for a CHD event as low,
intermediate, or high. Several calculators and models are available to quantify a person's 10-year risk for CHD
events. The Framingham Adult Treatment Panel III calculator (http://hp2010.nhlbihin.net/atpiii/calculator.aspThis link goes offsite. Click to read the external link disclaimer) performs well for the U.S. population. Persons with a 10-year risk greater than 20% are generally considered
high-risk, those with a 10-year risk less than 10% are considered low-risk, and those in the 10% to 20% range are
considered intermediate-risk.
Screening Tests
Many resting and exercise ECG abnormalities have been associated with an increased risk for CHD events, such as MI
and CHD death. Although exercise ECG is considered more sensitive for detecting coronary artery stenosis, the
magnitude of increased risk for CHD events, as well as the sensitivity of ECG abnormalities for predicting future
events, is similar for resting and exercise ECG1, 2. Performing baseline ECG so that results may be compared with future ECG findings is considered screening by the
USPSTF and is not recommended for asymptomatic adults at low risk for CHD; evidence is insufficient about its
usefulness in adults at increased risk.
For asymptomatic adults at low risk for CHD events, a resting or exercise ECG is unlikely to provide additional
information about CHD risk beyond that obtained with conventional CHD risk factors (that is, Framingham risk
factors) and result in changes in risk stratification that would prompt interventions and ultimately reduce
CHD-related events. False-positive results may cause harms in low-risk asymptomatic adults; for more information
about harms, go to the Suggestions for Practice Regarding the I Statement and the Discussion sections.
Treatment
Regardless of ECG findings, asymptomatic adults at increased risk for CHD are usually managed with a combination of
diet and exercise modifications, lipid-lowering medications, aspirin, hypertension management, and tobacco
cessation. The net benefit of the use of aspirin and the intensity of lipid-lowering therapy depends on a person's
baseline risk for CHD.
Useful Resources
The USPSTF has made recommendations on the use of aspirin to prevent CVD, screening for lipid disorders, the use of
additional risk factors to determine intermediate CHD risk, and screening for hypertension. These recommendations
and their supporting evidence are available on the USPSTF Web site at www.uspreventiveservicestaskforce.org.
Suggestions for Practice Regarding the I Statement
In deciding whether to screen with resting or exercise ECG in asymptomatic adults who are at intermediate or high
risk for CHD events, clinicians should consider the following.
Potential preventable burden. Although evidence is insufficient to
determine whether screening adults at increased risk is beneficial, those who are at intermediate risk for CHD
events have the greatest potential for net benefit from ECG screening. Reclassification into a higher risk category
might lead to more intensive medical management that could lower the risk for CHD events, but it might also result
in harms, including such adverse medication effects as gastrointestinal bleeding and hepatic injury. The
risk–benefit tradeoff would be most favorable if persons could be accurately reclassified from intermediate to
high risk. Regardless of ECG findings, persons who are already at high risk should receive intensive risk factor
modification and those who are already classified as low risk are unlikely to benefit.
For persons 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 exercise ECG, evidence is insufficient to determine the balance of benefits and harms of this
practice.
Potential harms. In all risk groups, an ECG abnormality (as a result
of a true- or false-positive result) can lead to invasive confirmatory testing and treatments that have the
potential for serious harm, including unnecessary radiation exposure and the associated risk for cancer. Studies
report that up to 3% of asymptomatic patients with an abnormal exercise ECG result receive angiography and up to
0.5% undergo revascularization, even though revascularization has not been shown to reduce CHD events in
asymptomatic persons. Angiography and revascularization are associated with risks, including bleeding,
contrast-induced nephropathy, and allergic reactions to the contrast agent.
Current practice. Screening with resting or exercise ECG in low-risk
patients is not recommended by any organization. However, evidence on current clinical use of screening for CHD with
resting or exercise ECG in asymptomatic patients is sparse. Anecdotal evidence suggests that it is performed with
some frequency.
Costs. Although the cost of resting ECG may be low, the downstream
costs of resulting diagnostic testing and treatments can be substantial.