Mass screening for atrial fibrillation (AF) using electrocardiography (ECG) alongside a heart failure biomarker does not reduce the incidence of ischemic stroke or systemic embolism among older adults aged 75 to 76, according to findings from a five-year study. However, the biomarker may enhance the prediction of individuals at low risk for these events beyond the use of single-lead ECG.
These insights were shared during the recent European Society of Cardiology (ESC) congress held in London from August 30 to September 2.
Katrin Kemp Gudmundsdottir from the Karolinska Institute in Sweden, lead author of the STROKESTOP II study, stated, “Our findings do not support systematic screening for AF in older adults. However, it may be safe to avoid targeted screening in individuals with low NT-proBNP [N-terminal pro-B-type natriuretic peptide] levels, although further studies are necessary to confirm this.”
Current AF guidelines worldwide advocate for opportunistic screening in individuals aged 65 and older, and the ESC recommends routine ECG screening for those aged 75 and above, particularly for those at higher stroke risk. There is also a belief that incorporating biomarkers could improve screening effectiveness, with NT-proBNP being identified as a significant predictor of AF and stroke risk.
In 2020, preliminary findings from the STROKESTOP II trial suggested that NT-proBNP could be a valuable tool for stratifying AF screening, indicating that individuals with high NT-proBNP levels might benefit from more intensive monitoring.
The STROKESTOP II study, which involved a mass screening initiative for all individuals aged 75 to 76 in Stockholm, enrolled 28,712 participants born between 1940 and 1941 to assess whether screening could lower the risk of thromboembolic events compared to a control group that was not invited for screening. Participants were divided in a 1:1 ratio, with 13,905 invited for AF screening and 13,884 in the control group, having excluded those who died or emigrated. Approximately 49% of those invited accepted the screening, with women constituting 53% of the attendees.
Participants without prior AF had their NT-proBNP levels analyzed, categorizing them into high-risk (≥125 ng/L) and low-risk (<125 ng/L) groups for screening purposes. The high-risk group (3,743 patients; 60%) underwent intensive monitoring at home using a handheld single-lead ECG device, while the low-risk group (2,545 patients; 40%) had a single screening session. Overall, new AF cases were identified in 2.4% of the participants, who were then offered oral anticoagulant treatment as per national registry data. After a median follow-up of five years, there was no significant difference in the risk of stroke or clotting events between the intervention and control groups. Subgroup analyses indicated a 41% lower risk of stroke or blood clots among participants with low NT-proBNP levels compared to the control group. In contrast, those in the high-risk group exhibited more than a doubled risk of developing new AF over five years and had a 57% higher risk of ischemic stroke or systemic embolism compared to their low-risk counterparts. Kemp Gudmundsdottir concluded, "Lower participation rates in the study may have impacted the results. Additional research is essential, and it would be sensible to focus screening efforts on individuals at the highest risk to potentially reduce preventable strokes."