Risk factors for parenchymal hematoma in hemorrhagic transformation after intra-arterial thrombectomy.

OBJECTIVE: To identify independent factors associated with hemorrhagic transformation (HT) in patients with acute ischemic stroke (AIS) after intra-arterial thrombectomy (IAT) and to determine predictors of parenchymal hematoma (PH) in patients who develop HT. METHODS: Among 2647 patients diagnosed with ischemic stroke or transient ischemic attack between April 1, 2020, and February 1, 2024, at a regional tertiary general hospital, 296 patients with AIS who underwent IAT were retrospectively analyzed. Patients were categorized into HT and non-HT groups. The HT group was subdivided into hemorrhagic infarction (HI) and PH groups. Comparative and multivariate regression analyses were performed between the HT and non-HT groups, and between the HI and PH subgroups. RESULTS: Older age (adjusted odds ratio aOR 1.037, 95% confidence interval CI 1.013-1.062, p = 0.003) and severe white matter hyperintensities (WMH) (Fazekas grade 3, aOR 2.875, 95% CI 1.705-4.848, p < 0.001) were independently associated with HT in patients with AIS after IAT. Among those with HT, PH was independently associated with atrial fibrillation (AF) (aOR 4.165, 95% CI 1.301-13.333, p = 0.016), total cholesterol (TC) level (aOR 0.978, 95% CI 0.962-0.993, p = 0.005), and erythrocyte sedimentation rate (ESR) (aOR 1.038, 95% CI 1.001-1.077, p = 0.045). CONCLUSION: Older age and severe WMH were identified as independent risk factors for HT in patients with AIS post-IAT. AF, lower TC (supporting the lipid paradox), and higher ESR were independently associated with PH among these patients. These findings highlight the key predictors of poor prognosis post-IAT, indicating ESR as a potential predictor of PH.