Differentiation of cancer from atrial fibrillation in patients with acute multifocal stroke

Objective Acute multifocal embolic infarction (AMEI) is conventionally caused by etiologies such as cardioembolism due to atrial fibrillation (Af), but can also be caused by serious underlying diseases such as cancer. We characterized cancer-related AMEI and identified useful indicators for cancer-associated strokes. Methods A retrospective analysis was performed on 35 patients with Af-related AMEI and 35 patients with cancer-related AMEI selected from 1235 consecutive patients with acute infarcts. All patients received diffusion-weighted magnetic resonance (MR) imaging. Cerebral MR angiography, carotid and cardiac ultrasonography, electrocardiogram-monitoring and whole body computed tomography were also performed on these patients. D-dimer levels were evaluated on admission, and were measured during the sub-acute phase in 19 of the patients with Af and 27 of the patients with cancer. Results Acute phase D-dimer levels were significantly higher in patients with cancer than in patients with Af alone. The cut-off D-dimer value to identify cancer-associated infarcts was 2.0 μg/mL. D-dimer levels during the sub-acute phase remained elevated in the cancer patients. Conclusions We may differentiate cancer-associated AMEI from Af using a D-dimer level ≥ 2.0 μg/mL, which does not decrease during the sub-acute phase.