Identifying the optimal time period for detection of atrial fibrillation after ischaemic stroke and TIA: An updated systematic review and meta-analysis of randomized control trials.

Background: Atrial fibrillation (AF) is a major risk factor for ischaemic stroke (IS) and transient ischaemic attack (TIA). The timely detection of first-diagnosed or "new" AF (nAF) would prompt a switch from antiplatelets to anticoagulation to reduce the risk of stroke recurrence; however, the optimal timing and duration of rhythm monitoring to detect nAF remains unclear.

Aims: We searched MEDLINE, PubMed, Cochrane database, and Google Scholar to undertake a systematic review and meta-analysis of randomized controlled trials (RCT) between 2012 and 2023 investigating nAF detection after IS and TIA. Outcome measures were overall detection of nAF (control; (usual care) compared to intervention; (continuous cardiac monitoring >72 h)) and the time period in which nAF detection is highest (0-14 days, 15-90 days, 91-180 days, or 181-365 days). A random-effects model with generic inverse variance weights was used to pool the most adjusted effect measure from each trial.

Summary of review: A total of eight RCTs investigated rhythm monitoring after IS, totaling 5820 patients. The meta-analysis of the studies suggested that continuous cardiac monitoring was associated with a pooled odds ratio of 3.81 (95% CI 2.14 to 6.77), compared to usual care (control), for nAF detection. In the time period analysis, the odds ratio for nAF detection at 0-14 days, 15-90 days, 91-180 days, 181-365 days were 1.79 (1.24-2.58); 2.01 (0.63-6.37); 0.98 (0.16-5.90); and 2.92 (1.30-6.56), respectively.

Conclusion: There is an almost fourfold increase in nAF detection with continuous cardiac monitoring, compared to usual care. The results also demonstrate two statistically significant time periods in nAF detection; at 0-14 days and 6-12 months following monitoring commencement. These data support the utilization of different monitoring methods to cover both time periods and a minimum of 1 year of monitoring to maximize nAF detection in patients after IS and TIA.