Screening for atrial fibrillation in 75- and 76-year-olds using thumb ECGS could reduce the risk of stroke, severe bleeding and death, according to a large-scale Swedish study.
Atrial fibrillation (AF) is associated with a five-fold increased risk of stroke, and the symptoms are often deleterious since large blood clots can form in the heart, breaking free and posing a stroke risk. Still, countries do not screen the general population for atrial fibrillation, but rather treat those patients who are discovered during routine care. This study by the Karolinska Institutet in Sweden and published in The Lancet, investigated the effectiveness of screening for AF.
“There has never really been a study that examines if it would be beneficial to screen for atrial fibrillation, which is why we wanted to investigate it,” said Emma Svennberg, cardiologist at the Karolinska University Hospital, Huddinge, and researcher at the Department of Medicine, Huddinge, Karolinska Institutet.
The study included almost 28 000 participants aged 75 or 76, randomised to be invited either to screening or to a control group, who received standard care. Of those invited to screening, more than half choose to participate. They completed a health questionnaire and performed a so-called thumb ECG (electrocardiogram), which involves placing one’s thumbs on an ECG device that measures the heart’s electrical activity.
Those without atrial fibrillation were asked to record their heart rhythm twice daily for two weeks using the ECG device which they took home. If the device registered irregular heart rhythms, the participants were referred to a cardiologist for a standardised work-up and, if there were no contra-indications, initiation of oral anticoagulant therapy.
The study’s 28 000 participants were then followed for at least five years. More detections of atrial fibrillation were recorded in the screening group, which also had a slightly lower incidence of death, stroke and severe bleeding than the control group.
“In total, 31.9 percent of those in the screening group experienced a negative event compared to 33 percent in the control group,” said Johan Engdahl, adjunct lecturer at the Department of Clinical Sciences, Danderyds Hospital, at Karolinska Institutet. “Now, that may sound like a small difference, but you must bear in mind that only about half of those invited to screening participated and it’s possible we would have seen a more pronounced difference had more people turned up for screening. Those who participated in the screening had significantly fewer negative events.”
Based on the findings, the researchers estimated that at least 2300 cases of stroke or death could be avoided per year in Sweden if a national screening of atrial fibrillation in the elderly was introduced.
Source: Karolinska Institute
