Use of CT perfusion to select patients with medium and distal vessel occlusions for thrombectomy: multicenter retrospective analysis

BACKGROUND: Early infarct growth rate (EIGR) provides a dynamic view of stroke progression. Use of CT perfusion (CTP) and EIGR has been thoroughly studied in large vessel occlusions, but not in distal or medium vessel occlusions (MeVOs). OBJECTIVE: We studied optimal thresholds for EIGR in MeVOs and assessed the use of EIGR and/or the absence of an ischemic core on CTP as practical selection criteria for endovascular thrombectomy (EVT). METHODS: This retrospective analysis included patients receiving CTP for MeVOs before EVT. The primary outcome assessed the ability of EIGR to predict good functional outcomes at 90 days (modified Rankin Scale (mRS) score of 0-2 or back to baseline) using receiver operator characteristic curve analysis. Secondary outcomes evaluated fast and slow progressors based on EIGR for functional outcome at 90 days, excellent reperfusion (thrombolysis in cerebral infarction score ≥2C), procedural complications, and symptomatic intracranial hemorrhage. RESULTS: Among 188 patients, 29.2% were fast progressors (EIGR ≥5 mL/hour). Slow progressors had significantly better 90 day mRS outcomes, with higher rates of good functional recovery (58.3%, 95% CI 50.0% to 66.4%; P=0.046). Multivariable analysis confirmed EIGR <5 mL/hour as an independent predictor of favorable outcomes. In posterior or anterior cerebral artery occlusion subgroup analysis, patients with no ischemic core on CTP had higher area under receiver operator characteristic curve (71.9%, 95% CI 54.5% to 89.3% P=0.013), outperforming EIGR thresholds. CONCLUSION: In this study, EIGR <5 mL/hour was associated with good 90 day outcomes in patients with MeVOs patients, supporting the use of EIGR as a practical selection criterion for EVT.