Abstract Number: Esoc2026a2105 Diffusion-Weighted Imaging Reversal After Thrombolysis in Acute Ischemic Stroke: Impact of Cerebral Small Vessel Disease Markers on Hemorrhagic Risk and Neurological Outcome

Abstract Background and aims While diffusion-weighted imaging (DWI) lesions exhibit partial reversibility after thrombolysis, the interplay between cerebral small vessel disease (CSVD), thrombolysis-related complications, and DWI reversal is incompletely understood. Methods This retrospective single-center study included acute ischemic stroke patients undergoing thrombolysis after brain MRI at hospital admission. A second MRI after 24±6 hours assessed infarct volume, DWI reversal, white matter hyperintensities (WMH) burden, and cerebral microbleeds (CMBs). sICH was defined according to Heidelberg Bleeding classification and DWI reversal as volume difference 0ml between the two MRIs. Uni- and multivariate regression models were performed, defining DWI reversal as outcome variable. Results Of 402 patients (age 74 years, 47.5% female) undergoing thrombolysis, 47 (12%) also underwent thrombectomy. DWI lesion reversal was observed in 105 (26.1%) of all patients with a median DWI reversal volume of 0.43ml interquartile range 0.13-2.86ml, independent of treatment modality, initial DWI volume, and the duration from stroke onset to thrombolysis. Larger baseline DWI lesion volume was associated with a higher likelihood of reversal, which was associated with improved neurological outcome, independent of age, stroke severity on admission, or present cardiovascular risk factors. Neither WMH volume nor the presence of CMB before thrombolysis was associated with DWI reversal, but CMB was a strong predictor of ICH. Conclusions DWI lesion reversal after in hyperacute stroke is common after reperfusion therapy and is associated with improved clinical outcome, irrespective of the presence of CSVD. DWI reversal following reperfusion therapy may impact on prognostication after stroke. Conflict of interest ML reports lecture fees: AstraZeneca; advisory board member: Servier; KGH reports speaker’s honouraria, consulting fees, lecture honouraria and/or study grants from Abbott, Amarin, AstraZeneca, Bayer Healthcare, Biotronik, Boehringer Ingelheim, Boston Scientific, Bristol-Myers Squibb, Daiichi Sankyo, Edwards Lifesciences, Medtronic, Novartis, Pfizer, Portola, Premier Research, Sanofi, SUN Pharma and W.L. Gore and Associates. All other authors have nothing to disclose