Jeffrey J. Goldberger, M.D., M.B.A., chief of the Cardiovascular Division and Raul D. Mitrani, M.D., professor of clinical medicine and director of clinical cardiac electrophysiology, in the Department of Medicine at the University of Miami Miller School of Medicine, contributed an editorial to the Journal of the American Medical Association about new recommendations from the U.S. Preventive Services Task Force (USPSTF) regarding the use of electrocardiogram screening to prevent cardioembolic strokes related to atrial fibrillation (AFib).
About 33 million people worldwide have AFib, the most common type of heart rhythm disorder, or arrhythmia, and a condition that can lead to stroke or death.
Given the substantial association between stroke and AFib, emerging hypotheses suggest that screening high-risk asymptomatic populations can identify patients with AFib who might be treated with anticoagulation, which can prevent strokes by 80 percent. However, in its recommendation, the USPSTF states that more evidence is needed to determine the benefits and potential harms of screening for AFib with ECGs in patients aged 65 and older with previously undiagnosed AFib.
In their editorial, Goldberger and Mitrani offer a comprehensive perspective and note that to consider ECG screening to prevent cardioembolic strokes related to AFib, it is necessary to consider the emerging evidence on the causal and temporal link between the rhythm disturbance of AFib and cardioembolic stroke.
“Although atrial fibrillation and atrial fibrillation burden are likely causally linked to cardioembolic stroke in some patients with AFib, this association is not causal in a substantial number of patients,” they wrote. Thus, Goldberger and Mitrani conclude that primary screening to prevent cardioembolic stroke may need to extend beyond ECGs.
“ECG screening at-risk populations is effective in identifying AFib cases, with more cases detected by more intensive screening,” wrote the physicians. “Anticoagulation for patients with incidentally identified AFib appears to prevent stroke.”
They also note that current screening for AFIb may be “the best available method to diagnose an underlying atrial myopathy that predisposes people to AFib-related cardioembolic stroke.” However, the current options and duration of screening are not sensitive nor precise enough to use as a sole approach. Overall, improved algorithms that show the interactions among risk scores, extent of atrial myopathy, and AFib burden are essential to optimize treatment.
The editorial clarifies that the goal for monitoring for asymptomatic AFib is to trigger anticoagulation to prevent stroke among patients with significant risk factors such as age, heart failure, hypertension and diabetes—assuming that AFib precedes cardioembolic stroke with enough warning and time to intervene with a prevention mechanism. However, AFib-related cardioembolic stroke (AFACES) commonly occurs in four different scenarios, which may or may not warrant ECG screening, Goldberger and Mitrani said:
1. When there is a case of known AFib, ECG screening is not needed.
2. When AFib is first diagnosed and occurs concurrently with stroke. In this case, an ECG would be ineffective due to the stroke occurring in close temporal proximity to the AFib. According to the editorial, using ECGs to prevent stroke needs to take the pathogenesis of AFib-related cardioembolic stroke into consideration, as it is assumed that AFib occurring prior to the stroke allows for sufficient time for a preventive intervention.
3. AFib is diagnosed during extended monitoring after a stroke, although the AFib may have been present but undetected prior to the stroke. The editorial states that performing intensive monitoring identifies more cases.
4. When AFib has not occurred prior to the stroke and is detected only after the stroke. In this scenario, Goldberger and Mitrani state that the association between AFib and stroke cannot be causal and that ECG screening would not be effective in this group of patients.
Among other highlights of the editorial, Goldberger and Mitrani agree with the USPSTF’s statement that the duration of screening, whether one day or one month long, is inadequate. However, while the USPSTF’s report alluded to potential risks associated with screening, such as misdiagnosis, Goldberger and Mitrani wrote that such risks should not be a factor in applying preventive services.
The physicians also note that devising an effective screening strategy to prevent AFib-related cardioembolic stroke “should be a public health priority.”