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Published on September 17, 2021

Better Detection of Irregular Heartbeats Could Prevent Future Strokes 

A Cone Health team took part in this important research. 

 

Dr. Pramod P. Sethi of Cone Health Stroke Center and Guilford Neurologic Research Associates knew that patients with atrial fibrillation (AFib) are more likely to have strokes, and that those strokes are more likely to be serious when they occur. He joined fellow neurologists, cardiologists and the cardiovascular research team at Cone Health to figure out a better way to detect AFib in those stroke patients. Their findings were published in the Journal of the American Medical Association and Science Magazine in June.  

Dr. Pramod Sethi

Pramod P. Sethi, MD 

The heart sends 40 percent of the blood it pumps each minute to the brain, but if the heart rate is irregular or the heart quivers, the blood can’t be pumped completely from the heart. AFib, a fast and irregular heart rhythm usually resulting from structural changes in the left upper chamber of the heart, can keep the blood stagnant. That can result in blood clots that can break loose and travel to the brain, causing a stroke.  

“AFib has been known to be a common cause of stroke, but it can be hard to diagnose as it is often elusive to capture,” Sethi said.   

When a link between strokes and AFib is detected, doctors can prescribe stronger blood thinners to help prevent subsequent strokes, but unless the presence of AFib is confirmed, those stronger medications aren’t advised due to their increased bleeding risk and cost.  

The researchers knew that many stroke patients weren’t receiving dedicated, long-term monitoring for AFib, hence it was being underdiagnosed. When an average stroke patient is in the hospital for the standard three or so days after the stroke, their heart activity is monitored. However, only about one percent of patients show AFib activity with this routine in-hospital monitoring.   

Current practice is to monitor only those patients who have no known cause of their stroke for a much longer period. In these longer-term monitored cases, about 35 percent of patients have shown AFib activity. The team wanted to take things a step further, to see if AFib might be affecting other stroke patients, too. Learning the answer to this question would help them prevent subsequent strokes for many more people.  

“We were recording heart rhythms only for patients where we couldn’t find any other cause for their stroke because we thought AFib might be present. But we changed our mindset for this study,” Sethi said. “We asked ourselves, ‘What if patients with a known cause of stroke could also have AFib as a contributing factor for current or future strokes?’”  

Implantable Heart Monitor

Reveal LINQ Implantable Heart Monitor

So, they sent 492 people who had strokes – even those with another known cause of stroke – home with a small heart monitor placed under the skin. Their findings?  

“In this study, we found a much higher rate of AFib – about 10 times higher – in patients with strokes from known causes than in the same kind of patients where we did the traditional monitoring in an office or in the hospital,” Sethi said.  

This research means providers will be able to help prevent some patients from having a second stroke from previously undiscovered AFib because they’ll be able to treat them with strong blood thinners to keep their blood from clotting due to their irregular heart rhythm. The blood thinners won’t fix the AFib, but they will significantly reduce the risk of stroke. There are still unanswered questions about whether finding silent AFib should be treated or not, and hopefully future studies will answer this question definitively.  

Dr. James Allred, director of the atrial fibrillation clinic at Cone Health's Heart & Vascular Center, was the primary cardiologist collaborating with Sethi on the trial. He says the findings underscore the importance of early diagnosis of AFib and close monitoring of stroke patients. 

Dr. James Allred

James Allred, MD

"We're really pleased to be advancing knowledge of the relationship between AFib and stroke," Allred said. "More than anything we want adults in our community over 40 to get annual checkups with their primary care provider, where irregular heart rhythms or other indicators of heart and vascular concerns can be identified early enough to prevent strokes and manage AFib."  

Sethi is proud of the collaboration of neurologists, the cardiovascular research team and cardiologists to find ways to provide better patient care. He coauthored this study with other leading neurologists and cardiologists, including physicians from Massachusetts General Hospital and Northwestern University Feinberg School of Medicine.  

For additional information on this study, you can read the write-ups in JAMA and Science Magazine