Extended AF Monitoring Worth Considering After Eye Stroke

June 14, 2021

Extended cardiac monitoring for the detection of atrial fibrillation (AF) should be considered in patients who have a stroke caused by central retinal artery occlusion, a new study suggests.

The study showed a high rate of device-detected AF in patients with central retinal artery occlusion, which was comparable to the rate in patients with cerebral ischemic stroke and higher than in matched controls.

The study was published online June 7 in the journal Stroke.

"Central retinal artery occlusion — also known as an eye stroke — causes sudden, irreversible blindness in one eye and is a form of acute ischemic stroke," lead author Brian Mac Grory, MB BCh, told Medscape Medical News.

Dr Brian Mac Grory

A recent cohort study found that 10% of patients with acute central retinal artery occlusion without a clear cause had AF on a 30-day cardiac event monitor, but the yield of extended cardiac monitoring in the diagnosis of new AF after an eye stroke is unknown, Mac Grory, a vascular neurologist at Duke University School of Medicine, Durham, North Carolina, noted.

To look more closely at the relationship between eye stroke and AF, the researchers conducted the current retrospective observational study in which information from two databases were cross referenced.

These were the Medtronic CareLink registry, which contains records from 2.7 million patients with implantable cardiac monitoring devices (insertable cardiac monitors, cardiac resynchronization therapy devices, or implantable pacemaker/defibrillators); and the Optum administrative dataset comprising electronic health records of approximately 30.8 million patients from 62 health systems in the United States.

"We identified patients who were in both databases and who had had a cerebral stroke or an eye stroke and matched them with patients also in both databases who had not had any type of stroke," Mac Grory explained.    

After reviewing 884,431 patient records in common between the two databases, the researchers identified 100 patients with an eye stroke, 6559 with ischemic stroke, and 1000 matched controls.

Results showed that patients who had an eye stroke were significantly more likely to have AF than matched patients without an eye stroke.

The cumulative incidence of new AF at 2 years was 49.6% on patients with an eye stroke. Patients with eye stroke had a significantly higher rate of AF than matched controls (hazard ratio, 1.64) and a comparable rate to patients with cerebral ischemic stroke (hazard ratio, 1.01).

Patients with eye stroke also had a higher incidence of new stroke compared with matched controls (hazard ratio, 2.85).

The higher rate of AF in patients with central retinal artery occlusion compared with controls argues for potential causal association between subclinical AF and this condition, the authors state. "Because of close matching between groups, it is unlikely that our findings would otherwise be explained solely by the higher risk of cardiac disease in these patients," they add.

The researchers suggest that AF should be considered in the differential etiology of central retinal artery occlusion, and long-term cardiac monitoring may be a reasonable option as part of the diagnostic workup in patients with eye stroke without known cause.

"Our study strengthens the link between eye stroke and AF. We can now cautiously say that if a patient has had an eye stroke it is reasonable to check for AF if no other reason for the stroke has been identified," Mac Grory said.

"As this was a retrospective study, it is not enough to change practice," he added. "More research is needed to be able to make stronger recommendations for monitoring, but I think this study poses an interesting question about monitoring in patients with these eye strokes, and it would be a reasonable thing to do."

Mac Grory noted that eye strokes are quite rare — accounting for less than 1% of all strokes. The condition is not often recognized as being a stroke, as it does not cause the traditional stroke symptoms of weakness and difficulty with speech and cognition, but rather presents as sudden painless vision loss in one eye.  

"Patients are rarely recognized to be having a medical emergency and are often referred to an eye clinic and a diagnosis of central retinal artery occlusion is often very delayed," Mac Grory commented. "But this condition needs more recognition. It should be viewed as a canary in the coal mine — that there is something wrong — as it can often be followed by a disabling brain stroke."

"If patients present with sudden vision loss in one eye, then an eye stroke should be considered. This can be treated with thrombolysis if patients get to the hospital within the 4.5-hour time window," he added.

This study did not receive any commercial funding. Mac Grory has disclosed no relevant financial relationships.

Stroke. Published online June 7, 2021. Abstract

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