USPSTF Examines ECG Screening to Prevent CVD Events, AFib

Lack of Evidence Precludes Recommendations for Many Adults

December 20, 2017 12:45 pm News Staff

On Dec. 19, the U.S. Preventive Services Task Force (USPSTF) posted a pair of draft recommendations and draft evidence reviews on using electrocardiographic screening to help characterize cardiovascular disease (CVD) risk in asymptomatic adults, as well as on using this screening tool to detect atrial fibrillation (AFib) in asymptomatic adults.

[electrocardiograph ecg waves in dark green]

CVD Risk Screening

In its draft statement(www.uspreventiveservicestaskforce.org) on screening to prevent CVD events, the USPSTF noted that treatment to prevent CVD events through risk factor modification is currently informed by CVD risk assessment tools such as the Framingham Risk Score or the Pooled Cohort Equations. These tools stratify individual risk based on factors such as age, race/ethnicity, gender, obesity, diabetes, smoking status, cholesterol levels and blood pressure.

The task force's draft evidence review(www.uspreventiveservicestaskforce.org) sought to determine whether screening with resting or exercise ECG improved calibration, discrimination or risk reclassification when added to such traditional CVD risk assessment models.

Based on its review, the task force found insufficient evidence 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 for such events -- an "I" recommendation.(www.uspreventiveservicestaskforce.org)

Story Highlights
  • On Dec. 19, the U.S. Preventive Services Task Force (USPSTF) posted a pair of draft recommendations and draft evidence reviews on using electrocardiographic screening to help characterize cardiovascular disease (CVD) risk in asymptomatic adults, as well as on using this screening tool to detect atrial fibrillation (AFib) in this population.
  • The USPSTF found insufficient evidence to assess the balance of benefits and harms of screening with resting or exercise electrocardiography (ECG) to prevent CVD events in adults at intermediate or high risk for CVD events -- an "I" recommendation.
  • Similarly, the task force concluded that current evidence is insufficient to assess the balance of benefits and harms of screening for AFib with ECG.

Additionally, the USPSTF recommended against screening with resting or exercise ECG to prevent CVD events in low-risk, asymptomatic adults -- a "D" recommendation.

Although the task force identified no studies that directly assessed whether adding resting ECG to current CVD risk assessment improves cardiovascular outcomes for any risk group, it did find two fair-quality randomized, controlled trials of screening with exercise ECG in patients with diabetes that showed no difference in mortality or cardiovascular events. However, "both trials fell far short of their intended enrollment and therefore were underpowered and had a relatively short time period (mean, 3.5 years) to detect a difference in cardiovascular outcomes," the statement noted.

"The evidence shows that people at low risk of CVD do not benefit from screening with ECG," said USPSTF member Seth Landefeld, M.D., in a news release(www.uspreventiveservicestaskforce.org) that covered both the CVD and AFib draft statements. "For patients with elevated risk levels, clinicians should continue to use traditional risk factors to assess CVD risk and guide treatment until more evidence is available."

This draft recommendation statement is consistent with the task force's 2012 final recommendation statement,(www.uspreventiveservicestaskforce.org) as well as with the AAFP's own 2012 recommendations.  

Screening for AFib

AFib affects nearly 3 million Americans and sometimes isn't detected until after patients have a stroke; the condition accounts for 14 percent to 24 percent of all ischemic strokes. Patients with persistent and permanent AFib have the highest risk of stroke, but even paroxysmal AFib (about 25 percent of all AFib cases) increases stroke incidence.

The USPSTF's draft recommendation statement(www.uspreventiveservicestaskforce.org) and draft evidence review(www.uspreventiveservicestaskforce.org) on electrocardiographic screening for AFib mark the first time the task force has examined this topic.

Based on its review, the USPSTF concluded that current evidence is insufficient to assess the balance of benefits and harms of screening for AFib with ECG -- an "I" recommendation.

"We need more research to determine whether screening for AFib with ECG can help prevent strokes," said USPSTF member Alex Krist, M.D., M.P.H., in the release. "Trials in people without signs or symptoms of AFib that compare screening with ECG to usual care will help fill this research gap."

One such anticipated trial is the STROKESTOP study in Sweden, which has randomized 28,768 adults ages 75-76 for screening (or not) -- first with 12-lead ECG and then intermittently with a handheld single-lead ECG device for two weeks. The primary outcome is stroke incidence, and results are anticipated in 2019.

Up Next

The USPSTF is inviting comments on its draft recommendation statement(www.uspreventiveservicestaskforce.org) and draft evidence review(www.uspreventiveservicestaskforce.org) on electrocardiographic screening to prevent CVD events, as well as on its draft recommendation statement(www.uspreventiveservicestaskforce.org) and draft evidence review(www.uspreventiveservicestaskforce.org) on screening for AFib using ECG.

The public comment window is open until 8 p.m. EST on Jan. 22. All comments received will be considered as the task force prepares its final recommendations.

The AAFP will review the USPSTF's draft recommendation statements and supporting evidence and provide comments to the task force. The Academy will release its own recommendation on the topic after the task force finalizes its guidance.

Related AAFP News Coverage
Don't Use Screening ECG to Predict Coronary Events in Low-Risk Adults, Say AAFP, USPSTF
(8/1/2012)