Background and purpose Collateral assessment using CT angiography is a promising modality for selecting patients for endovascular thrombectomy (EVT) in the late window (6–24 hours). The outcome of these patients compared with those selected using perfusion imaging is not clear.
Methods We pooled data from seven trials and registries of EVT-treated patients in the late-time window. Patients were classified according to the baseline imaging into collateral imaging alone (collateral cohort) and perfusion plus collateral imaging (perfusion cohort). The primary outcome was the proportion of patients achieving independent 90-day functional outcome (modified Rankin Scale ‘mRS’ 0–2). We used the propensity score–weighting method to balance important predictors between the cohorts.
Results In 608 patients, the median onset/last-known-well to emergency arrival time was 8.8 hours and 53.2% had wake-up strokes. Both cohorts had collateral imaging and 379 (62.3%) had perfusion imaging. Independent functional outcome was achieved in 43.1% overall: 168/379 patients (45.5%) in the perfusion cohort versus 94/214 (43.9%) in the collateral cohort (p=0.71). A logistic regression model adjusting for inverse-probability-weighting showed no difference in 90-day mRS score of 0–2 among the perfusion versus collateral cohorts (adjusted OR 1.05, 95% CI 0.69 to 1.59, p=0.83) or in a favourable shift in 90-day mRS (common adjusted OR 1.01, 95% CI 0.69 to 1.47, p=0.97).
Conclusion This pooled analysis of late window EVT showed comparable functional outcomes in patients selected for EVT using collateral imaging alone compared with patients selected using perfusion and collateral imaging.
PROSPERO registration number CRD42020222003.
- image analysis
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information.
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Correction notice This article has been corrected since it first published. A colon has been added to the title for clarity.
Contributors MAA and BKM conceived the manuscript idea and organised the data collection. MAA, BJK, AA and BKM developed the statistical analysis plan and performed the analyses. The rest of the coauthors participated in the data collection from their respective registries and trials. MAA drafted the manuscript. All authors discussed the results and contributed to the final manuscript. MAA acts as guarantor and accepts full responsibility for the work and/or the conduct of the study, had access to the data, and controlled the decision to publish.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests MAA reports being a member of the scientific advisory board of Palmera Medical. AD reports personal fees from Medtronic. MG reports grants or personal fees from Medtronic, Stryker, Microvention, Cerenovus, and has a patent Systems of Acute Stroke Diagnosis issued to GE Healthcare. MDH has received grant support from Medtronic, consultant fees from Boehringer Ingelheim and speaker’s fees from Amgen. SM acted as a consultant for Cerenovus. BKM reports shares in Circle NVI; patent for systems of triage in acute stroke. Dr Patrik reports research grants from the Swiss Heart Foundation and the Swiss National Science Foundation. DT received honoraria as a member of advisory board of Abbott, Boehringer Ingelheim, Bayer, Pfizer-BMS, Medtronic and Daiichi Sankyo. The other authors report no conflicts.
Provenance and peer review Not commissioned; externally peer reviewed.
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