Association between basal ganglia infarction and hemorrhagic transformation after mechanical thrombectomy in acute ischemic stroke: insights from the DIRECT-MT trial

BACKGROUND: Acute ischemic stroke (AIS) often leads to significant morbidity and mortality. Mechanical thrombectomy (MT) is an effective intervention for large vessel occlusion strokes. However, hemorrhagic transformation (HT) remains a critical post-procedural complication. This study investigates the relationship between basal ganglia infarction (BGI) and the risk of HT, particularly focusing on hemorrhagic infarction (HI) and parenchymal hematoma (PH). METHODS: Data from the DIRECT-MT trial were analyzed. Patients were categorized based on the presence of BGI identified on initial non-contrast CT. HT was classified into HI and PH following the Heidelberg criteria. Multivariate logistic regression, propensity score matching (PSM), and inverse probability of treatment weighting (IPTW) were used to assess the association between BGI and HT. RESULTS: Among 607 patients, 273 had BGI. BGI was associated with a higher risk of HT, specifically PH. The incidence of PH in the BGI group was 20% compared with 11% in the non-BGI group. Adjusted analyses, including PSM and IPTW, confirmed the significant association between BGI and PH with an adjusted odds ratio (aOR) of 2.51 (95% CI 1.49 to 4.22, P<0.001). However, no significant association was found between BGI and HI. CONCLUSIONS: BGI significantly increases the risk of PH following MT for AIS, underscoring the need for tailored therapeutic strategies in managing these patients. No significant correlation was observed between BGI and HI. Future research should explore the underlying mechanisms and validate these findings across diverse populations to improve patient outcomes.