Thrombolysis in Large Diffusion-Weighted Imaging Lesions: Lower Chance but Still a Chance

Abstract

We sought to investigate whether early thrombolytic treatment can result in favorable functional outcome even in patients with large diffusion-weighted imaging (DWI) lesions. We analyzed 566 patients who received intravenous alteplase within 4.5 hours from onset, initially underwent DWI and magnetic resonance angiography, and had acute infarction confined to anterior circulation. DWI lesion volumes were measured semiautomatically. The association between DWI lesion volume and 3-month outcome in patients who achieved early recanalization was assessed. The DWI lesion volume cutoff, which predicts unfavorable outcome despite recanalization, was determined. In patients with large DWI lesions, the distributions of modified Rankin Scale (mRS) score were compared according to the recanalization status. Four hundred thirty-six patients achieved early recanalization. Among these patients, 283 (65%) patients had a favorable functional outcome (mRS score 0-2). DWI lesion volume (odds ratio [OR], 1.38 per 10 mL; 95% confidence interval [CI], 1.22-1.56) was an independent variable associated with poor outcome, along with hypertension (OR, 1.87; 95% CI, 1.12-3.10), National Institutes of Health Stroke Scale (NIHSS) score (OR, 1.13; 95% CI, 1.08-1.19), and onset-to-needle time (OR, 1.08 per 10 minutes; 95% CI, 1.03-1.13). The DWI lesion of 60 mL or higher highly predicted an unfavorable outcome with a positive predictive value of 95.3%. In patients with a DWI lesion of 60 mL or higher, recanalization had no benefit for an mRS score of 0-2 but was significantly associated with an mRS score of 0-3 (OR, 4.64; 95% CI, 1.08-19.97). Despite early recanalization, the probability of favorable outcome is low in patients with a DWI lesion of 60 mL or higher. Nevertheless, the benefit of recanalization still persists in large DWI lesions.