Factors Associated with Poor Outcome after Successful Reperfusion in Patients with Large Infarct: A Post-Hoc Analysis of the TENSION Trial

BACKGROUND: Endovascular thrombectomy (EVT) improves outcomes in acute ischemic stroke caused by large-vessel occlusion. However, many patients experience poor functional outcomes despite successful reperfusion. In patients with large infarct cores, associated patient and treatment characteristics remain poorly understood. This study aimed to identify pre- and post-treatment variables associated with poor functional outcomes despite successful reperfusion in the TENSION trial. METHODS: This secondary analysis included patients from the TENSION trial who achieved successful reperfusion (TICI ≥2b). Poor outcome was defined as modified Rankin Scale >3 at 12 months. Univariable and multivariable logistic regression were used to identify pre- and post-treatment factors associated with poor outcome. RESULTS: Of 110 patients with successful reperfusion, 68 (62%) experienced poor outcomes. These patients were older (77 vs. 67 years, p<0.001), had higher baseline NIHSS (20 vs. 16, p<0.001), higher NIHSS at 24 hours (19 vs. 7, p<0.001), larger infarct volumes (253 vs. 122 mL, p<0.001), more serious adverse events (76% vs. 15%, p<0.001), and higher pneumonia rates (24% vs. 2.4%, p=0.003). In multivariable analysis, independent pre-treatment factors associated with poor outcome were baseline NIHSS (OR 1.23, 95% CI 1.03–1.47, p=0.02), IV-alteplase (OR 4.61, 95% CI 1.29–16.5, p=0.02), and longer time to recanalization (OR 6.67, 95% CI 1.64–27.2, p=0.008). Post-treatment factors were NIHSS at 24 hours (OR 1.18, 95% CI 1.08–1.31, p<0.001), infarct volume (OR 1.06 per 10 mL, 95% CI 1.00–1.12, p=0.045), and pneumonia (OR 14.1, 95% CI 1.58–1863.3, p=0.01). CONCLUSIONS: Approximately 60% of patients with large infarct have poor outcomes despite successful reperfusion. Higher baseline NIHSS, IV-alteplase administration, longer time to recanalization, higher 24-hour NIHSS, larger 24-hour infarct volume, and pneumonia were independently associated with poor outcome, with a differential pattern across mortality and non-fatal severe disability. These findings warrant confirmation in future prospective studies.