Table 18Summary of Evidence

Number of studiesLimitationsConsistencyPrimary care applicabilitySummary of findings
KQ 1. What are the benefits of screening for abnormalities on resting or exercise ECG compared to no screening on CHD outcomes?
No studiesNo studies met inclusion criteriaNo evidenceNo evidenceNo randomized controlled trials or controlled observational studies on screening asymptomatic adults for CHD with resting or exercise ECG versus no screening were identified.
KQ 2. How does the identification of high-risk persons via resting or exercise ECG affect use of treatments to reduce cardiovascular risk?
No studiesNo studies met inclusion criteriaNo evidenceNo evidenceNo studies that evaluated how screening individuals for CHD using resting or exercise ECGs affects use of interventions to reduce cardiovascular risk were identified.
KQ 3. What is the accuracy of resting or exercise ECG for stratifying persons into high-, intermediate-, and low-risk groups?
63 studies
Overall quality rating: fair
No study estimated how adding ECG results to traditional risk factors affected discrimination or calibration, or provided data to enable the construction of risk stratification tablesConsistentHighNo study estimated how accurately resting or exercise ECG plus traditional risk factor assessment classified subjects into high-, intermediate-, or low-risk groups compared to classification based on traditional risk factor assessment alone, or provided data to enable the construction of risk stratification tables in order to estimate risk reclassification rates. Two studies found that resting or exercise ECG findings plus traditional risk factor assessment resulted in a slight increase in the C statistic compared to traditional risk factor assessment alone, but differences were not statistically significant in one study, and the level of statistical significance was not reported in the other.

Pooled analyses showed that abnormalities on resting (ST segment or T wave abnormalities, LVH, bundle branch block, left axis deviation) or exercise (ST segment depression with exercise, failure to reach maximum target heart rate) ECG were associated with an increased risk (HR estimates from 1.4 to 2.1) of subsequent cardiovascular events, after adjusting for traditional risk factors. Statistical heterogeneity was present in a number of analyses, but stratification of studies by method of defining the ECG abnormality, study quality, or the type of cardiovascular events evaluated did not reduce heterogeneity and resulted in similar estimates.

Low versus high exercise capacity or fitness during exercise ECG was also associated with increased risk of subsequent cardiovascular events or all-cause mortality (HR estimates from 1.7 to 3.1), but results from individual studies could not be pooled.
KQ 4. What are the harms of screening with resting or exercise ECG?
2 studies
Overall quality rating: poor
Only two uncontrolled studies examined harms associated with screening ECGConsistentLow (limited evidence)No studies reported harms directly associated with screening with resting ECG. One study (included in the previous report) found no complications in 377 subjects who underwent screening with exercise ECG. No studies reported downstream harms associated with followup testing or interventions after screening with resting or exercise ECG.

Abbreviations: CHD=coronary heart disease; ECG=electrocardiography; HR=hazard ratio; KQ=key question; LVH=left ventricular hypertrophy.

From: 4, Discussion

Cover of Screening Asymptomatic Adults for Coronary Heart Disease With Resting or Exercise Electrocardiography
Screening Asymptomatic Adults for Coronary Heart Disease With Resting or Exercise Electrocardiography: Systematic Review to Update the 2004 U.S. Preventive Services Task Force Recommendation [Internet].
Evidence Syntheses, No. 88.
Chou R, Arora B, Dana T, et al.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.