Clinical and Neuroimaging Characteristics in Embolic Stroke of Undetermined versus Cardioembolic Origin: A Population-Based Study.

BACKGROUND AND PURPOSE Evidence suggests that cardioembolism represents the underlying mechanism in the minority of embolic strokes of undetermined source (ESUS). In this population-based study, we sought to compare the clinical and imaging characteristics as well as outcomes in patients with ESUS and cardioembolic stroke (CE). METHODS We included consecutive patients with first-ever ischemic stroke (IS) from the previously published population-based Evros-Stroke-Registry identified as ESUS or CE according to standardized criteria. Baseline characteristics, admission NIHSS scores, cerebral edema, hemorrhagic transformation, stroke recurrence, functional outcomes (determined by modified Rankin Scale [mRS] scores), and mortality rates were recorded during the 1-year follow-up period. RESULTS We identified 21 ESUS (3.7% of IS) and 211 CE (37.1% of IS) cases. Patients with ESUS were younger (median age: 68 years [interquartile range [IQR]: 61-75] vs 80 years [IQR: 75-84]; P < .001), had lower median admission NIHSS scores (4 points [IQR: 2-8] vs 10 points [IQR: 5-17]; P < .001), and lower prevalence of cerebral edema on neuroimaging studies (0 vs. 33.3%, P = .002). Functional outcomes were more favorable in ESUS at 28 (median mRS score: 2 [IQR: 1-3] vs 4 [IQR: 4-5]; P < .001), 90 (median mRS score: 1 [IQR: 0-2] vs 4 [IQR: 3-5]; P < .001), and 365 days (median mRS score: 1 [IQR: 0-2] vs 4 [IQR: 2-4]; P < 0.001). At 1-year, the mortality rate was lower in ESUS (0% [95% confidence interval [CI]: 0-13.5%] vs 34.6% [95% CI: 28.2-41.0%]; P < .001); the 1-year recurrent rate was also lower numerically (0% [95% CI: 0-13.5%] vs 9.5% [95% CI: 5.5-13.4%]; P = .140) but this difference failed to reach statistical significance due to the small study population. CONCLUSIONS The clinical and neuroimaging profiles as well as clinical outcomes vary substantially between ESUS and CE indicating different underlying mechanisms.