Insular involvement and atrial fibrillation first detected after ischemic stroke: a systematic review and meta-analysis

PURPOSE: The association between insular involvement identified on brain imaging and atrial fibrillation first detected after ischemic stroke remains uncertain. We evaluated this association and summarized prespecified neurocardiac outcomes. METHODS: Seven databases were searched through April 5, 2026; six were searched from inception, and Wanfang Data was searched from January 2000. Eligible studies enrolled adults with ischemic stroke, assessed insular involvement on brain imaging, and reported atrial fibrillation or another prespecified neurocardiac outcome. Atrial fibrillation first detected after stroke was defined as atrial fibrillation identified after the index stroke in patients without previously known atrial fibrillation. Random-effects meta-analysis was performed when at least three studies were sufficiently comparable. RESULTS: Thirty-one studies were included; only three provided comparable adjusted estimates for the primary meta-analysis, totaling 2164 participants. Insular involvement was associated with higher odds of atrial fibrillation first detected after stroke (odds ratio 3.35, 95% confidence interval 2.30-4.89; P < 0.001). An exploratory analysis of overall atrial fibrillation excluding one atrial flutter event yielded an odds ratio of 1.51 (95% confidence interval 0.99-2.32; P = 0.056). Other outcomes were summarized descriptively. CONCLUSION: Across three observational studies, insular involvement identified on brain imaging was associated with atrial fibrillation first detected after ischemic stroke. Previously undetected paroxysmal atrial fibrillation may have preceded the stroke, leaving the temporal direction uncertain. These findings are hypothesis-generating and are insufficient to support the use of lesion location to select rhythm monitoring strategies or guide anticoagulation decisions.