Noncontrast CT versus Perfusion‐Based Core Estimation in Large Vessel Occlusion: The Blood Pressure after Endovascular Stroke Therapy Study

Abstract

BACKGROUND AND PURPOSE The 2018 AHA guidelines recommend perfusion imaging to select patients with acute large vessel occlusion (LVO) for thrombectomy in the extended window. However, the relationship between noncontrast CT and CT perfusion imaging has not been sufficiently characterized >6 hours after last known normal (LKN). METHODS From a multicenter prospective cohort of consecutive adults who underwent thrombectomy for anterior LVO 0–24 hours after LKN, we correlated baseline core volume (rCBF < 30%) and the Alberta Stroke Program Early CT Scale (ASPECTS) score. We compared perfusion findings between patients with an unfavorable ASPECTS (<6) against those with a favorable ASPECTS (≥6), and assessed findings over time. RESULTS Of 485 enrolled patients, 177 met inclusion criteria (median age: 69 years, interquartile range [IQR: 57‐81], 49% female, median ASPECTS 8 [IQR: 6‐9], median core 10 cc [IQR: 0‐30]). ASPECTS and core volume moderately correlated (r = −.37). A 0 cc core was observed in 54 (31%) patients, 70% of whom had ASPECTS <10. Of the 28 patients with ASPECTS <6, 3 (11%) had a 0 cc core. After adjustment for age and stroke severity, there was a lower ASPECTS for every 1 hour delay from LKN (cOR: 0.95, 95% confidence of interval [CI]: 0.91‐1.00, P = .04). There was no difference in core (P = .51) or penumbra volumes (P = .87) across patients over time. CONCLUSIONS In this multicenter prospective cohort of patients who underwent thrombectomy, one‐third of patients had normal CTP core volumes despite nearly three quarters of patients showing ischemic changes on CT. This finding emphasizes the need to carefully assess both noncontrast and perfusion imaging when considering thrombectomy eligibility.

Correlation of Alberta Stroke Program Early Computed Tomography Score With Computed Tomography Perfusion Core in Large Vessel Occlusion in Delayed Time Windows

“…To the best of our knowledge, there is only one other study that included a delayed time window (105 patients presenting >6 hours) to study the association of baseline ASPECTS and CTP core. 10 For comparison between NCCT and CTA-SI, our study is in contrast with previous studies, 5,[11][12][13] which showed that CTA-SI are more reliable than NCCT for ASPECTS scoring in early time windows. We found that baseline…”

Noncontrast Computed Tomography vs Computed Tomography Perfusion or Magnetic Resonance Imaging Selection in Late Presentation of Stroke With Large-Vessel Occlusion

“…Better clinical outcomes can be observed among patients selected on optimal CTP parameters, but this selection may improve overall statistics at the cost of denying care to many patients who could benefit. Moreover, CTP is vulnerable to infarct core overestimation, which may inappropriately exclude patients from treatment. It is not well established whether advanced neuroimaging is indispensable or if NCCT may be sufficient for identifying patients with large-vessel occlusion likely to benefit from endovascular thrombectomy who present in the extended window.…”

Mechanical thrombectomy versus medical care alone in large ischemic core: An up-to-date meta-analysis

“…Whereas, James E Siegler et al. 32 considered NCCT-ASPECTS and core volume just moderately correlated (r s =−0.37, p < 0.01). Besides, collateral status could serve as selection criterion for thrombectomy in large infarcts patients, just as the guidelines suggested (level IIB).…”