Randomized Invitation to Systematic NT-proBNP and ECG Screening in 75-Year-Olds to Detect Atrial Fibrillation: STROKESTOP II.

Background: Guidelines have suggested screening for atrial fibrillation to enable early treatment and avoid downstream negative clinical events. We aimed to determine whether atrial fibrillation screening potentially enhanced by NT-proBNP (N-terminal pro-B-type natriuretic peptide) would reduce stroke or systemic embolism incidence compared with a control group and to determine whether it was safe for those with low NT-proBNP concentrations to forfeit prolonged screening.

Methods: In this randomized controlled trial, all 75- and 76-year-old individuals in Stockholm Region, Sweden, were randomized 1:1 to be invited to screening or serve as a control group. NT-proBNP concentrations were measured, and a single-lead ECG was registered only once if NT-proBNP <125 ng/L, whereas if NT-proBNP ≥125 ng/L, participants underwent prolonged screening, recording single-lead ECGs 4 times daily for 2 weeks. If atrial fibrillation was detected, treatment was initiated. Baseline and outcome data were collected from Swedish National Registries.

Results: In total, 28 712 individuals were randomized. After exclusion of death and emigration, 13 905 remained in the intervention group, 13 884 in the control group. The participation rate in the intervention group was 49.2% (6843 of 13 905). Participants in the high NT-proBNP group (NT-proBNP≥125 ng/L) without previous atrial fibrillation constituted 60% of the total and underwent prolonged screening. New atrial fibrillation was detected in 2.4% (165 of 6843) in the intervention group. There was no difference in atrial fibrillation prevalence or oral anticoagulant treatment between the intervention and the control group after 5 years of follow-up. After a median of 5.1 years (interquartile range, 5.0-5.8), there was no difference in the primary outcome of stroke or systemic embolism between the intervention group and the control group (hazard ratio, 0.96 [95% CI, 0.86-1.06]). The low NT-proBNP group had significantly fewer strokes or systemic emboli than the control group (hazard ratio, 0.59 [95% CI, 0.46-0.74]; P<0.001). In the high NT-proBNP group, the risk of stroke or systemic embolism was higher compared with the low NT-proBNP group (hazard ratio, 1.57 [95% CI, 1.22-2.02]; P=0.001).

Conclusions: In this population-based screening trial for atrial fibrillation using NT-proBNP for screening enhancement, there was no difference in risk of stroke or systemic embolism for the intervention group compared with controls. Participation was moderate. The use of NT-proBNP for screening enhancement was safe in identifying low-risk participants.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02743416.