What is the evidence for a screening electrocardiogram (ECG)?

From the Guidelines

Routine screening electrocardiograms (ECGs) in asymptomatic adults are not recommended due to insufficient evidence of their benefits in preventing coronary heart disease (CHD) events. The U.S. Preventive Services Task Force (USPSTF) has stated that the current evidence is insufficient to determine whether screening adults at increased risk is beneficial 1.

Key Considerations

• The potential benefits of ECG screening are thought to be greatest in individuals at intermediate risk for CHD events, as reclassification into a higher risk category might lead to more intensive medical management and a reduction in CHD risk.
• However, ECG screening may also result in harms, including false-positive results, unnecessary invasive testing, and adverse medication effects.
• Certain occupations, such as pilots and heavy equipment operators, may require ECG screening due to the potential risks of sudden incapacitation or death.

Limitations of ECG Screening

• ECG abnormalities 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 have reported 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 1.

Clinical Decision-Making

• Clinicians should consider individual risk factors and discuss the limitations of ECG screening with patients to ensure informed decision-making.
• Targeted ECG screening may be appropriate for specific high-risk groups, including those with hypertension, diabetes, family history of sudden cardiac death, or athletes participating in competitive sports.
• A normal ECG does not rule out all cardiac conditions and may provide false reassurance, highlighting the need for a comprehensive approach to cardiovascular risk assessment.

From the Research

Evidence for Screening Electrocardiogram (ECG)

The evidence for screening electrocardiogram (ECG) is summarized as follows:

• Screening asymptomatic people with a resting electrocardiogram (ECG) has been theorized to detect latent cardiovascular disease, but it is not recommended for numerous populations, such as asymptomatic middle-aged (sedentary) people, as it is not sufficiently sensitive to detect coronary artery disease 2.
• The US Preventive Services Task Force (USPSTF) recommends against screening with resting or exercise ECG to prevent CVD events in asymptomatic adults at low risk of CVD events, and 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 3.
• Abnormalities on resting or exercise ECG are associated with an increased risk for subsequent cardiovascular events after adjustment for traditional risk factors, but the clinical implications of these findings are unclear 4.
• The addition of resting ECG to traditional risk factors produced small improvements in discrimination and appropriate risk classification for prediction of multiple cardiovascular outcomes, although evidence was limited by imprecision, quality, considerable heterogeneity, and inconsistent use of risk thresholds used for clinical decision making 5.
• Exercise ECG testing may be recommended for asymptomatic men with diabetes and asymptomatic men over age 45 with two or more CV risk factors prior to initiating a vigorous exercise programme, but more conclusive data is needed to demonstrate the ability to decrease incident CV events using preparticipation screening exercise ECG testing in adult athletes 6.

Key Findings

• Resting ECG screening is not recommended for asymptomatic middle-aged (sedentary) people due to its limited sensitivity in detecting coronary artery disease 2.
• The USPSTF recommends against screening with resting or exercise ECG in asymptomatic adults at low risk of CVD events, but the evidence is insufficient to assess the balance of benefits and harms in asymptomatic adults at intermediate or high risk of CVD events 3.
• Abnormalities on resting or exercise ECG are associated with increased risk of cardiovascular events, but the clinical implications are unclear 4.
• The addition of resting ECG to traditional risk factors may improve discrimination and risk classification, but the evidence is limited 5.
• Exercise ECG testing may be recommended for certain high-risk populations, such as asymptomatic men with diabetes or multiple CV risk factors, prior to initiating a vigorous exercise programme 6.