BACKGROUND Recent trials of endovascular thrombectomy (EVT) for acute distal medium vessel occlusions (DMVOs) were negative but also used inconsistent imaging‐based inclusion criteria, whereas many successful large vessel occlusion (LVO) EVT trials used empirically validated perfusion imaging‐based target mismatch (TMM) criteria: an ischemic penumbra (time‐to‐maximum Tmax >6 s) to core (relative cerebral blood flow rCBF 4 s, >6 s, >8 s, and >10 s volumes correlated with follow‐up infarct volumes in unrecanalized patients. Then, we evaluated whether these improved parameters for core and penumbra better quantified LVO TMM and identified an optimal DMVO TMM definition. RESULTS In 122 core (recanalized) patients, rCBF 8 s most strongly correlated with follow‐up infarct volumes (concordance correlation coefficient 0.49 0.25–0.77), outperforming Tmax >6 s (concordance correlation coefficient 0.39 0.17‐0.68) ( P 6 s to rCBF 8 s and rCBF 8 s to rCBF 8 s best correspond to ischemic core and penumbra, respectively; more favorably quantify LVO TMM; and reveal optimal TMM criteria. These results should be prospectively investigated as inclusion criteria for EVT in this population and suggest recent negative DMVO EVT trials may have been confounded by suboptimal patient selection.
Cai et al. (Wed,) studied this question.