Despite recent study findings, jury is still out on screening ECGs

It’s not unusual for adult patients to undergo a 12-lead electrocardiography (ECG) during or soon after a preventive health visit. A 2017 analysis of administrative data in Ontario, Canada, found that more than 1 in 5 patients had an ECG within 30 days of a routine checkup. Unsurprisingly, patients with screening ECGs were more likely than others to receive additional cardiac tests, visits, or procedures. However, no significant differences in mortality, hospitalizations for cardiac reasons, or coronary revascularization between the groups were reported.

The U.S. Preventive Services Task Force (USPSTF) has consistently recommended against using ECG to screen for coronary heart disease in asymptomatic, low-risk adults. This recommendation was also included in the Choosing Wisely campaign. The rationale for not testing is that ECGs are unlikely to benefit these patients but can initiate harmful cascades of care. Nonetheless, research on the use of ECGs to identify patients with undiagnosed atrial fibrillation and other potentially serious abnormalities has continued. A 2019 report summarized previous studies that found associations between abnormal screening ECGs and worse cardiovascular outcomes after adjusting for traditional risk factors.

A recent study took advantage of the practice of performing ECGs as a mandatory part of annual health checks in Japanese adults 35 to 65 years of age. In the study, 3.7 million individuals with no history of cardiovascular disease or prior abnormal ECGs had an ECG in 2016 and were followed for a median of 5.5 years for the composite outcome of all-cause death or hospital admission for cardiovascular disease; 17% had one minor ECG abnormality, 4% had two or more minor abnormalities, and 1.5% had a major abnormality. Compared with people with normal ECGs, those with any ECG abnormality had a greater risk of experiencing the composite outcome.

In an accompanying commentary, former USPSTF member and family physician Alex Krist, MD, MPH, explained why these results probably will not change current recommendations:

For clinicians and patients, merely knowing that someone is at risk for an adverse event is not helpful without knowing what should be done to reduce that risk. There are multiple effective and recommended strategies to reduce people’s risk of CVD, including statin use for people at risk, screening for and managing hypertension, and counseling for healthy diet, exercise, and smoking cessation. Clinicians should routinely offer all of these preventive services to patients irrespective of whether their ECG result is normal or abnormal. Before recommending screening ECG, future studies will need to show that doing something different in response to an abnormal ECG changes a health outcome for a person.

A 2018 Lown Right Care article by Drs. Alan Roth, Andy Lazris, and Sarju Ganatra discussed overuse of cardiac tests in asymptomatic patients, including ECG, stress tests, and coronary artery calcium scoring.

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This post first appeared on the AFP Community Blog.