Karissa C. Arthur, MD
Jadhav AP, Goyal M, Ospel J, Campbell BC, Majoie CBLM, Dippel DW, White P, Bracard S, Guillemin F, Davalos A, et al. Thrombectomy With and Without Computed Tomography Perfusion Imaging in the Early Time Window: A Pooled Analysis of Patient-Level Data. Stroke. 2022.
Computed tomography perfusion (CTP) imaging is currently used for patients with large vessel occlusions presenting in the late time window. However, it is uncertain if CTP adds value to decision making in the early time window. In this study, Jadhav et al. set out to compare post-endovascular thrombectomy (EVT) outcomes between patients who received the standard noncontrast CT and CT angiography (CTA) versus those who received additional imaging with CTP. They further determined the association between CTP and clinical outcomes.
The data studied was pooled patient data from the HERMES collaboration of seven randomized controlled trials that investigated safety and efficacy of EVT in patients with large vessel ischemic stroke. Outcomes of interest included good functional outcome defined as modified Rankin Scale (mRS) 0-1 at 90 days, NIHSS at 24 hours, and change between baseline and 24 hour NIHSS. Safety outcomes were mortality at 90 days and symptomatic intracranial hemorrhage within 5 days of randomization. A total of 1348 patients were included, of which 610 (45.3%) had baseline CTP imaging. Baseline characteristics, occlusion location, and time to treatment were similar between those who received baseline CTP and those who did not. EVT was more beneficial than medical management alone in both groups. There was no difference in good functional outcome, NIHSS at 24 hours, change in NIHSS, symptomatic ICH, or mortality at 90 days between the group which had baseline CTP imaging and the group that did not.
The authors noted that the lack of favorable association of baseline CTP imaging with good functional outcome may have been due to inclusion of poor quality CTP, overestimation of ischemic core in early time window with CTP, or difference in software interpretation, which are commonly faced issues in clinical practice. Therefore, it was felt that CTP likely does not add benefit as opposed to CT/CTA alone in the early time window. Further, it does add risk of higher radiation and contrast volume. Notably, however, there was no difference in time from onset to groin puncture between the two groups, suggesting that CTP does not delay treatment. Therefore, while CTP may not add additional benefit to those patients within the 6-hour time window who fit trial criteria for EVT, it may have additional benefit in those patients who do not fit top tier criteria.