<h3>Introduction</h3> Ischaemic stroke remains a leading cause of long-term disability and mortality worldwide. A large proportion of ischemic strokes remain aetiologically undifferentiated despite thorough investigation. These strokes are often termed cryptogenic (CS) and also include a subset which have an embolic pattern on brain imaging (embolic stroke of undetermined source, ESUS). Assessment of clinical and structural cardiac factors following stroke may aid in discrimination of cardioembolic stroke (CES) subtypes in this population. We sought to assess the strengths of association of clinical and structural cardiac factors with diagnosed CES in comparison with CS and ESUS populations. <h3>Methods</h3> A systematic review of medical databases and grey literature was performed utilising the PRISMA statement (2000–2023; PROSPERO registration CRD42023426712) (figure 1). Various data points were individually extracted and meta-analysed using a random effects model, with values being assessed through odds ratio (OR) and standardised mean difference (SMD). <h3>Results</h3> We analysed 80 studies involving a total of 15,669 patients (3,886 CES patients vs 11,783 CS / ESUS patients). CES patients tended to be older (ESUS; OR 0.409, 95% CI: 0.281 to 0.537; p&lt;0.001) with higher rates of hypertension (CS; OR 1.455; 95% CI 1.213 to 1.744, p&lt;0.001) (ESUS; OR 1.706; 95% CI: 1.236 to 2.356; p=0.001) and heart failure (CS; OR 2.289; 95% CI 1.329 to 3.940, p=0.003). Further, this population had an overall increase in left atrial (LA) size (CS; 0.667; 95% CI 0.513 to 0.820; p&lt;0.001) (ESUS; SMD 0.810; 95% CI 0.562 to 1.058; p&lt;0.001) and impairment of LA reservoir function (CS; SMD -1.190, 95% CI -1.461 to -0.919; p&lt;0.001) when compared to patients with CS and ESUS. See table 1. <h3>Conclusion</h3> These findings identify key clinical risk factors and structural cardiac changes which are associated with cardioembolic stroke mechanisms. Aggressive surveillance for subclinical atrial fibrillation in these patients may be warranted. <h3>Conflict of Interest</h3> None

185 Echocardiographic and clinical parameters in cardioembolic strokes compared with cryptogenic stroke and embolic stroke of undetermined source