Abstract WMP91: The Penumbra Salvage Index (PSI) As A Novel Measure Of Successful Reperfusion

Abstract

Objective: We propose a novel measure, the PSI, to evaluate procedural success and prognostication after EVT and compare its prognostic ability with successful reperfusion (mTICI ≥2b). Methods: SELECT EVT patients with adequate follow-up MR DWI imaging were stratified based on PSI [ratio of salvaged tissue volume (Tmax >6s volume at baseline – f/up DWI infarct volume) to the Tmax >6s volume at baseline] into good (PSI≥50%) and poor penumbral salvage (PSI<50%). Multivariable regression models examined the association of PSI with functional outcomes as well as predictors of PSI. ROC curve analysis evaluated the predictive ability of PSI and compared it with mTICI≥2b. Results: 142/206(69%) had good penumbral salvage, with better CT ASPECTS (Good PSI: 9(7-10) vs Poor PSI: 7(6-9),p<0.001), baseline core infarct (Good PSI: 5.9(0.0-20.0)ml vs Poor PSI: 19.4(3.4-46.3)ml, p<0.001) and mTICI≥2b (Good PSI:91% vs Poor PSI: 64%, p<0.001). Good PSI was independently associated with higher odds of mRS 0-2 (Good PSI: 69% vs Poor PSI: 26%, aOR:5.89, 95%CI:2.25-15.45, p<0.001) and mRS 0-1 (Good PSI: 56% vs Poor PSI: 16%, aOR: 4.98, 95%CI:1.86-13.31, p=0.001). Predictors of a good PSI included a lower presenting NIHSS (aOR: 0.93, 95%CI: 0.87-0.99, p=0.026), smaller ischemic core (aOR: 0.96, 95%CI: 0.95-0.98, p<0.001) larger Tmax>6s volume (aOR: 1.01, 95%CI: 1.00-1.02, p=0.003) and mTICI≥2b (aOR: 8.84, 95%CI: 3.16-24.71, p<0.001). PSI demonstrated better AUC values (0.811) as compared to mTICI≥2b (0.786) in the ROC analysis. Conclusion: Good penumbral salvage is associated with higher odds of functional independence, and has a better predictive value than successful reperfusion on cerebral angiogram after EVT. Prospective studies are needed to confirm the predictive utility of the PSI.

Pretreatment CT perfusion collateral parameters correlate with penumbra salvage in middle cerebral artery occlusion

“…The DWI infarct volume was manually segmented by one board‐certified radiologist (MH, 5 years of working experience). Penumbral salvage index was defined as the ratio of salvaged tissue volume (Tmax >6 seconds volume at baseline—DWI infarct volume during admission) to the Tmax >6 seconds volume at baseline 20 …”

“…Penumbral salvage index was defined as the ratio of salvaged tissue volume (Tmax >6 seconds volume at baseline-DWI infarct volume during admission) to the Tmax >6 seconds volume at baseline. 20 The mTICI score was determined by the performing neurointerventionalist at the time of the procedure.…”

“…PSI is defined as the ratio of the Tmax > 6 seconds volume minus the follow-up diffusion-weighted imaging (DWI) volume to the Tmax > 6 seconds volume. 20 Good penumbral salvage is associated with higher odds of functional independence and has a better predictive value than successful reperfusion after MT. PSI has the potential to serve as a reliable in-hospital predictor of long-term outcomes.…”

“…Another promising predictive biomarker of clinical outcomes is the Penumbra Salvage Index (PSI). PSI is defined as the ratio of the Tmax > 6 seconds volume minus the follow‐up diffusion‐weighted imaging (DWI) volume to the Tmax > 6 seconds volume 20 . Good penumbral salvage is associated with higher odds of functional independence and has a better predictive value than successful reperfusion after MT.…”