LAUSR

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The LOOP Study was funded by Innovation Fund Denmark [grant number 12-1352259], The Research Foundation for the Capital Region of Denmark, The Danish Heart Foundation [grant number 11-04-R83-A3363-22625], Aalborg University Talent Management Program, Arvid Nilssons Fond, Skibsreder Per Henriksen, R og Hustrus Fond, the European Union’s Horizon 2020 program [grant number 847770], Læge Sophus Carl Emil Friis og hustru Olga Doris Friis’ Legat, and an unrestricted grant from Medtronic. Background It is well known that atrial fibrillation (AF) confers a substantially increased risk of ischemic stroke, but data on health benefits from AF screening are scarce. The newly proposed MVP risk score combining the duration, voltage and morphology of P-wave has been demonstrated to be predictive of AF and might therefore also be useful in risk-stratifying individuals for AF screening and subsequent treatment. Purpose The present study sought to examine MVP risk score and its P-wave components for prediction of AF screening effects. Methods The LOOP Study randomized AF-naïve individuals aged 70-90 years with additional stroke risk factors to either continuous AF screening with implantable loop recorder (ILR) and subsequent anticoagulation initiation upon detection of AF episode ≥6 minutes, or usual care. In this secondary analysis, the LOOP participants with a baseline 12-lead electrocardiogram (ECG) suitable for P-wave measurement were included. Results Of 5759 participants included, 265 (4.6%) had had ischemic stroke during follow-up: 213 (4.9%) of 4311 in the control group versus 64 (3.6%) of 1448 in the ILR group. Among the participants in the control group, a significantly increased risk of ischemic stroke was observed for MVP score 5-6 versus score 0-2 (hazard ratio (HR) 1.66 [95% confidence interval (CI): 1.01-2.75]) and for the presence of interatrial block (IAB) versus no IAB (HR 1.85 [95% CI: 1.19-2.86]), whereas a P-wave voltage in lead I (PWVI) <100 µV was associated with risk reduction compared to higher voltage (HR 0.65 [95% CI: 0.45-0.93]). Further spline analysis revealed longer P-wave duration (PWD) to also be correlated with higher stroke risk (HR 1.49 [95% CI: 1.11-2.00] for >110 versus ≤110 ms). Compared with usual care, ILR screening did not significantly reduce the stroke risk regardless of MVP risk score, PWD, PWVI, or IAB pattern at baseline. Conclusions In an elderly population with additional stroke risk factors, both the P-wave parameters and the combined MVP risk score based on 12-lead ECG were associated with ischemic stroke, but these did not successfully demonstrate an association with effects of AF screening on stroke prevention. MVP ECG risk score Ischemic stroke in the control group