Grade: I The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of the service. Evidence is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined.
The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening with resting or exercise ECG to prevent CVD events in asymptomatic adults at intermediate or high risk of CVD events. See the Clinical Considerations section for suggestions for practice regarding the I statement.
Frequency of Service
No information available.
Risk Factor Information
No information available.
This recommendation applies to adults without symptoms of or a diagnosis of CVD.
Suggestions for Practice Regarding the I Statement
In deciding whether to screen with resting or exercise ECG in asymptomatic adults at intermediate or high risk of CVD events, clinicians should consider the following information.
Potential Preventable Burden
Although evidence is insufficient to determine whether screening with ECG in adults is beneficial, those who may be at increased risk of CVD events might have the greatest potential for net benefit. Reclassification into a higher-risk category might lead to more intensive medical management that could lower the risk of CVD events but might also result in harms, including adverse medication effects such as gastrointestinal bleeding and hepatic injury. Regardless of ECG findings, persons who are already at high risk of CVD events should receive intensive risk factor modification. Persons who are classified as low risk are unlikely to benefit from screening with ECG.
For persons in certain occupations, such as pilots and operators of heavy equipment, for whom sudden incapacitation or death may endanger the safety of others, considerations other than the health benefit to the patient may influence the decision to screen with ECG to prevent CVD events.
In all risk groups, an abnormal ECG finding (a true-positive or false-positive result) can lead to invasive confirmatory testing and treatment that have the potential for serious harm, including unnecessary radiation exposure. Two studies of asymptomatic adults with diabetes reported that 6% and 12% of patients who were screened with exercise ECG subsequently underwent angiography, and 3% to 5% underwent revascularization, without evidence of benefit to the study patients.1, 2 Angiography and revascularization are associated with harms, including bleeding, contrast-induced nephropathy, cardiac arrhythmia, stroke, myocardial infarction, coronary artery dissection, allergic reaction to the contrast agent, and death.
Although many guideline groups recommend cardiovascular risk assessment, there are few data on how this is applied in clinical practice. Only 41% of respondents in a survey of more than 900 US clinicians reported using cardiovascular risk prediction equations in practice.3 There are few data on the use of ECG to assess CVD risk in asymptomatic patients in the United States. A Canadian retrospective cohort study from 2010 to 2015 found that 21.5% of low-risk primary care patients had an ECG within 30 days of an annual health examination, and the proportion of patients who had an ECG ranged across clinics from 1.8% to 76.1%.4
Assessment of Risk
Accurate identification of persons at high risk of CVD events provides the opportunity for more intensive risk factor management to reduce the likelihood of such an event. In addition, identifying persons at low risk may allow for a reduction in interventions among patients not likely to benefit from them.
Several factors are associated with an increased risk of CVD events, including older age, male sex, high blood pressure, current smoking, abnormal lipid levels, diabetes, obesity, and physical inactivity. Risk factors are combined in many ways to estimate a person's risk of a CVD event. Several calculators and models are available to quantify a person's 10-year risk of CVD events. The Framingham Risk Score,5 based on data from the Framingham Heart Study, was one of the first widely used CVD risk assessment tools. Persons with a 10-year CVD event risk greater than 20% are generally considered high risk, those with a 10-year CVD event risk less than 10% are considered low risk, and those with a 10-year CVD event risk of 10% to 20% are considered intermediate risk. The Pooled Cohort Equations, introduced by the American College of Cardiology and American Heart Association in 2013, include the same variables as the Framingham Risk Score as well as race/ethnicity and diabetes. Persons with a 10-year CVD event risk less than 7.5% are considered at low risk, and those with a 10-year CVD event risk of 7.5% or greater are considered at elevated risk.6 The USPSTF recommends that clinicians use the Pooled Cohort Equations to assess CVD risk.
Both resting and exercise ECG are used for the diagnostic evaluation of suspected CVD, which has led to the suggestion that ECG could also be used to screen asymptomatic persons to identify those who would benefit from earlier, more intensive management of modifiable risk factors, preventive interventions, or both. Resting ECG records cardiac electrical activity while the patient is at rest, over a short period of time. Standard ECG testing is performed with 12 leads, although some tests use fewer leads. More recently, ECG leads have been built into blood pressure cuffs, smartphones, and other devices. Exercise ECG records cardiac electrical activity during physical exertion, often at a prespecified intensity level. The most common method of exercise ECG is the treadmill test, but other methods, such as those using bicycles and ergometers, have also been used. Both resting and exercise ECG look for markers of previous myocardial infarction, myocardial ischemia, and other cardiac abnormalities (such as left ventricular hypertrophy, bundle branch block, or arrhythmia) that may be associated with CVD or predict future CVD events.
Treatment and Interventions
Asymptomatic adults at increased risk of CVD events are usually treated with a combination of diet and exercise modifications, lipid-lowering medications, aspirin, hypertension management, and interventions to encourage tobacco cessation. Recommendations for diet and exercise modifications, lipid-lowering medications, and aspirin are based on level of cardiovascular risk. Recent guidelines also recommend risk stratification of hypertension treatment;7 the recommendation for tobacco cessation applies to all persons regardless of CVD risk.
The USPSTF has made recommendations on many factors related to CVD prevention, including screening for high blood pressure,8 use of statins,9 counseling on smoking cessation,10 and counseling to promote healthful diet and physical activity.11 In addition, the USPSTF recommends low-dose aspirin use in certain persons at increased risk of CVD events.12
Other resources are also available from the National Heart, Lung, and Blood Institute;13 Centers for Disease Control and Prevention;14 and Healthy People 2020.15
Research Needs and Gaps
A considerable number of studies have reported hazard ratios and other measures of association between ECG changes and cardiovascular outcomes, so additional studies of this nature are unlikely to advance the field. Studies are needed that assess the incremental value of adding ECG to current CVD risk assessment tools or instruments to directly inform decision making; studies that examine patient outcomes would be most useful. Failing that, studies are needed that assess the added value of ECG for risk reclassification across clinically relevant risk thresholds. Any study of CVD risk assessment should also evaluate the harms associated with assessment as well as those related to additional testing and treatment. Studies that measure risk reclassification should report total, event, and nonevent Net Reclassification Indices, with corresponding confidence intervals, as well as measures of calibration and discrimination.
Update of Previous USPSTF Recommendation
This recommendation is an update of the 2012 USPSTF recommendation. As in 2012, the USPSTF continues to recommend against screening with ECG in adults at low risk, and the evidence remains insufficient on screening in adults at increased risk.17
Cardiovascular disease, which encompasses atherosclerotic conditions such as coronary heart disease, cerebrovascular disease, and peripheral arterial disease, is the most common cause of death among adults in the United States. Treatment to prevent CVD events by modifying risk factors is currently informed by CVD risk assessment with tools such as the Framingham Risk Score or the Pooled Cohort Equations, which stratify individual risk to inform treatment decisions. If existing CVD risk assessment tools could be improved, treatment might be better targeted, thereby maximizing the benefits of and minimizing the harms of screening.
The USPSTF found inadequate evidence to determine whether adding resting or exercise ECG to conventional risk factor assessment leads to improved risk stratification of persons to inform treatment decisions.
Benefits of Early Detection and Intervention and Treatment
The USPSTF found inadequate evidence to determine whether the incremental information offered by resting or exercise ECG (beyond that obtained with traditional CVD risk factors) can be used to guide treatment decisions and ultimately reduce CVD events.
Based on the epidemiology and natural history of CVD and established treatment strategies based on risk stratification, it is unlikely that the benefits of screening with resting or exercise ECG in asymptomatic adults at low risk of CVD events are greater than small.
See the Clinical Considerations section for definition of risk categories and assessment of risk.
Harms of Early Detection and Intervention and Treatment
The USPSTF found adequate evidence that screening with resting or exercise ECG in asymptomatic adults leads to harms that are at least small and may be moderate, including unnecessary invasive procedures, overtreatment, and labeling.
The USPSTF concludes with moderate certainty that the potential harms of screening with resting or exercise ECG to prevent CVD events equal or exceed the potential benefits in asymptomatic adults at low risk of CVD events.
The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening with resting or exercise ECG to prevent CVD events in asymptomatic adults at intermediate or high risk of CVD events.
Recommendations of OthersThe American College of Physicians recommends against screening for CVD with resting or stress ECG in asymptomatic, low-risk adults.32 The American College of Cardiology concludes that exercise ECG is rarely appropriate in asymptomatic adults at low global risk of CVD events, may be an appropriate option for adults at intermediate risk, and is appropriate for adults at high risk.33 In 2012, the American Academy of Family Physicians recommended against screening with ECG in asymptomatic, low-risk persons.34 The American College of Preventive Medicine recommends against routinely screening with resting or exercise ECG in the general adult population.35
- JAMA Patient Page: Screening for Cardiovascular Disease Risk With ECG
- Screening for Cardiovascular Disease Risk With Electrocardiography: AFP's Putting Prevention Into PracticeThe journal American Family Physician (AFP) provides a series of short case studies and quizzes based on recommendations issued by the U.S. Preventive Services Task Force.