Post-EVT CTP as a Patient-Selection Tool for Adjuvant Therapy: Review, Meta-Analysis, and Clinical Threshold Framework

Background and PurposeDespite high rates of macrovascular recanalization, approximately half of patients with large vessel occlusion stroke fail to achieve functional independence after endovascular thrombectomy (EVT). Residual tissue-level perfusion abnormalities on post-procedural CT perfusion (CTP) may indicate futile recanalization and inform selection for adjuvant therapy. We synthesized post-EVT CTP thresholds, summarized acquisition timing, and discussed implications for patient selection in trials of intra-arterial thrombolysis, antithrombotics, and neuroprotection, limited to studies performing perfusion imaging after EVT. MethodsWe searched MEDLINE, EMBASE, and the Cochrane Library (January 2018-April 2026) for studies performing perfusion imaging after EVT, reporting [&ge;]1 quantitative CTP parameter with functional or neurological outcome, and enrolling [&ge;]10 patients; pre-EVT CTP studies were excluded. Functional independence with versus without post-EVT hypoperfusion was pooled using DerSimonian-Laird random-effects. Individual patient data from our prospective Cerebrolysin proof-of-concept cohort (N=18) were integrated. ResultsNine post-EVT perfusion imaging studies (497 patients) met inclusion criteria. Residual hypoperfusion occurred in 21-53% of angiographically successful reperfusions and was associated with lower odds of functional independence (pooled OR 0.23, 95% CI 0.17-0.33; I{superscript 2}=29%). A Tmax >6 s volume <3.5 mL at 30-90 minutes post-EVT was the most consistently validated threshold (OR 3.5, 95% CI 1.6-7.8). In our cohort, an ischemic core (rCBF <30%) of 0 mL versus any detectable residual core was associated with markedly higher odds of independence (OR 27.5, 95% CI 1.0-746 with continuity correction; {rho}=0.77, p=0.003). The optimal CTP acquisition window is 30-120 minutes post-EVT. ConclusionsPost-EVT CTP outperforms modified TICI grading for predicting functional outcome and identifies biologically distinct subgroups for adjuvant therapy selection. Standardized post-EVT CTP at 30-120 minutes, applied with the proposed threshold framework, should be used for eligibility and stratification in future trials of intra-arterial thrombolysis, antithrombotics, and neuroprotection.