A recent study presented at the European Society of Cardiology (ESC) congress has found that mass screening for atrial fibrillation (AF) in older adults, utilizing electrocardiography (ECG) alongside a heart failure biomarker, does not significantly reduce the rates of ischaemic stroke or systemic embolism over a five-year period. However, the biomarker may assist in identifying individuals at low risk for these events during mass AF screening in older adults aged 75 to 76.
Katrin Kemp Gudmundsdottir from the Karolinska Institute in Stockholm, lead author of the STROKESTOP II study, stated that the findings indicate systematic screening for AF in older adults may not be beneficial. She added that individuals with low levels of NT-proBNP, a heart failure biomarker, faced a lower risk of developing AF as well as lower rates of stroke or systemic embolism compared to those with elevated levels and the control group.
Current guidelines for AF screening recommend opportunistic screening for individuals aged 65 and over, alongside anticoagulant treatments for those deemed at high risk for strokes. The ESC further advocates for systematic ECG screenings in individuals aged 75 and older, believing that integrating biomarkers could improve screening precision. NT-proBNP has shown promise as a key predictor of new-onset AF and strokes.
The STROKESTOP II initiative involved a mass screening program for 75 to 76-year-olds in Stockholm, enrolling over 28,700 participants born between 1940 and 1941. The study aimed to determine whether screening invitations would lower the risk of thromboembolic events compared to a control group that did not receive invitations.
Out of the participants, 13,905 were invited for AF screening, while 13,884 remained in the control group after excluding deaths and emigrants. Of those invited, nearly half accepted, with 53% being women. Blood samples were taken from participants without a prior AF diagnosis to evaluate NT-proBNP levels, categorizing them into high-risk and low-risk groups for subsequent screening.
In the high-risk group, more intensive at-home screening was performed, while low-risk individuals underwent a single screening session. The study ultimately detected new AF in 2.4% of participants who were subsequently prescribed oral anticoagulants. After five years of follow-up, researchers found no significant differences in stroke or clotting events between the intervention group and the control group.
Further analysis revealed that participants with low NT-proBNP levels had a 41% lower risk of stroke or blood clots compared to the control group, while those in the high-risk category faced more than double the risk of new AF and a 57% higher risk of ischaemic stroke or systemic embolism.
Kemp Gudmundsdottir highlighted that lower-than-expected participation in the screening study might have influenced the results, urging further research to focus on high-risk individuals to effectively reduce preventable strokes.