Multi-phase CT-Angiography outperforms angiographic careggi collateral score and predicts functional outcome in acute ischemic stroke.

Background: Collaterals are a strong determinant of clinical outcome in acute ischemic stroke (AIS) patients undergoing Endovascular Treatment (EVT). Careggi Collateral Score (CCS) is an angiographic score that demonstrated to be superior to the widely suggested ASITN/SIR score. Multi-phase CT-Angiography (mCTA) could be alternatively adopted for collateral assessment. We investigated whether mCTA had an equivalent predictive performance for functional outcome compared to CCS.
Methods: Consecutive AIS patients undergoing EVT for large vessel occlusion within 24 h from onset were analyzed. Receiver operating characteristic curves and multivariable logistic regression were investigated to evaluate the predictive performance of mCTA collateral score (range 0-5) and CCS (range 0-4) for good functional outcome (three-months modified Rankin Scale 0-2).
Results: We included 201 subjects (59.7% females, mean age 75), of whom 96 (47.7%) had good outcome at three-months. Both CCS (OR = 14.4, 95% CI = 6.3-33.8) and mCTA (OR = 23.8, 95% CI = 10.1-56.4) collateral scores were independent predictors of outcome. The AUC of CCS was 0.80 (95% CI 0.73-0.86) and the best cut-off was ≥ 3 (87% sensitivity, 71% specificity), while the AUC of mCTA collateral score was 0.84 (95% CI 0.78-0.90) with an optimal cut-off of ≥ 4 (85% sensitivity, 87% specificity). Patients with good mCTA collaterals experienced smaller (16.6 vs. 63.7 mL, p < 0.001) infarct lesion as compared to those with mCTA poor collaterals.
Conclusion: mCTA discriminative ability for three-months 0-2 mRS was found to be comparable to CCS. mCTA appears a valid, non-invasive imaging modality for evaluating collaterals of AIS patients potentially eligible for EVT.
Competing Interests: Declarations. Conflicting interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Dr. Morotti received expert meeting and advisory board honoraria from EMG-REG International and AstraZeneca. Ethical approval: The study was approved by the Ethics Committee of the University of Florence (Ethics Committee Approval code: 26299). All procedures performed in studies involving human participants were conducted in accordance with the ethical standards of the institutional and/or national research committee and with the 1975 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent: Informed consent was obtained from all individual participants involved in the study.
(© 2024. Fondazione Società Italiana di Neurologia.)