David Conen, MD, MPH, on the Role of Clinically Silent Brain Infarcts on Cognitive Decline Among Patients With AFib: Results From Swiss-AF

In this video, David Conen, MD, MPH, provides insight into the results of the Swiss Atrial Fibrillation Cohort (Swiss-AF) trial and what they reveal about the incidence of clinically silent brain infarcts among patients with AF who are receiving anticoagulation therapy. Dr Conen also explains how the results can help guide future treatment decisions for patients with AF so that the risk of cognitive decline, dementia, and stroke can be reduced. The findings were presented as a late-breaking clinical trial as part of Heart Rhythm Society 2020 Science. 

Additional Resource:

Conen D, Krisai P, Rodondi N, et al. D-LBCT03-02: Incidence of silent brain infarcts in anticoagulated patients with atrial fibrillation. Presented at Heart Rhythm Society 2020 Science. https://www.hrsonline.org/HRS2020Science  

David Conen, MD, MPH, is an associate professor, Division of Cardiology, Department of Medicine, at McMaster University in Hamilton, Ontario, Canada.


David Conen: My name is David Conen, and I'm a researcher at McMaster University. Today I will present you a study that we conducted with our colleagues in Switzerland.

We were interested in the relationship between cognitive dysfunction and atrial fibrillation because previous studies have shown that patients with atrial fibrillation have a higher risk of getting cognitive dysfunction and dementia compared to other members of the general population. For this purpose, we collected data on 1227 patients with brain MRI imaging and cognitive testing at baseline. And then the same tests, including brain MRI and cognitive testing, were repeated after approximately 2 years of follow up.

Brain infarcts were [centrally] collected … and were centrally adjudicated. Clinically silent brain infarcts were defined as new infarcts in patients without an intercurrent stroke or TIA. We only considered new lesions—meaning regions that were not present at the baseline MRI.

We assembled a group of AF patients with the mean age of 71 years. About half of the patients had paradoxical atrial fibrillation, about 20% had a history of congestive heart failure. The mean CHA2DS2-VASc score as a measure of stroke risk was 3.0. And importantly, almost 90% of all participants were taking oral anticoagulation throughout the 2 years of follow up.

We found that 68 patients—or 5.5%—had a new brain infarct at the 2-year MRI. Fifty-eight of these 68 patients had a silent event. Fifty-nine of the 68 patients were taking oral anticoagulation throughout the follow-up period. And 51—or 75%—of the patients had a silent event, while they were taking oral anticoagulation.

These brain infarcts had an impact on cognitive decline. We found that patients who had a brain infarct had a stronger cognitive decline compared to patients without brain infarcts. These differences are clinically small but statistically significant for most assessment scales.

We concluded from this study that about 5.5% of all treated atrial fibrillation patients have a new brain infarct after 2 years of follow-up. The great majority of these infarcts is clinically silent and occurs in patients who are taking oral anticoagulation.

New brain infarcts were significantly associated with cognitive decline. Although these differences were clinically small, they were occurring during a follow-up period of only 2 years. And we know that cognitive decline and dementia takes a long time to become clinically apparent, so we are currently conducting a long-term follow-up in this patient population to assess the true clinical consequences of our findings.

And finally, although many atrial fibrillation patients benefit from oral anticoagulation, oral anticoagulation alone may not be sufficient to prevent brain damage in all atrial fibrillation patients.

Thanks for listening to our study findings, and hopefully we can chat soon in person. Thank you.

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