Reperfusion Within 6 Hours Outperforms Recanalization in Predicting Penumbra Salvage, Lesion Growth, Final Infarct, and Clinical Outcome

Abstract

Background and Purpose— The relative merits of reperfusion versus recanalization to predict tissue and clinical outcomes in anterior circulation stroke have been previously assessed using data acquired >12 hours postonset. To avoid late-occurring confounders such as non-nutritional reperfusion, futile recanalization and no-reflow phenomenon, we performed ultraearly assessment of reperfusion and recanalization. Methods— From a multicenter prospective database, 46 patients with acute magnetic resonance angiography–visible occlusion and in whom both reperfusion and recanalization were assessed on follow-up magnetic resonance imaging ≤6 hours of symptom onset were identified. Multiple linear regressions modeled salvaged penumbra, diffusion-weighted imaging lesion growth, and final infarct at 1 month using baseline clinical and imaging parameters and acute reperfusion or recanalization. Best predictors were determined with the Akaike information criterion. Univariate and multivariate logistic regressions identified the clinical and imaging predictors of clinical outcome. Results— Admission magnetic resonance imaging showed M1 occlusion in 15 (33%) patients; median penumbra volume was 13.4 mL. Acute reperfusion was observed in 27 (59%) patients; 42% of nonrecanalized patients demonstrated reperfusion. The dichotomized classification of reperfusion and recanalization was discordant ( P =0.0002). Reperfusion ≤6 hours was a significant ( P <0.05) predictor of increased penumbra salvage, reduced lesion growth, and final infarct size. Recanalization did not improve model accuracy. Reperfusion, but not recanalization, was significantly associated with good clinical outcome in logistic regressions. Conclusions— Reperfusion ≤6 hours was consistently superior to recanalization in predicting tissue and clinical outcome. Reperfusion without recanalization was frequent and probably related to retrograde reperfusion through leptomeningeal collaterals. Acute reperfusion was the strongest predictor of, and may therefore, represent a reliable surrogate for, clinical outcome.

Does Diffusion Lesion Volume Above 70 mL Preclude Favorable Outcome Despite Post-Thrombolysis Recanalization?

“…22 Among recanalizers with DWI≥70 mL, we found a greater amount (median 19 mL) of lesion reversal in patients with favorable as compared with unfavorable outcome. This finding is consistent with previous work indicating that DWI lesion reversal is mediated by early reperfusion, 21,33 is more frequent and sizeable in patients treated in the early time frame, 20,22 and is associated with favorable 3-month outcome across all DWI lesion volumes. 20 Importantly, the present study is the first to show that the phenomenon of DWI reversal applies to lesion volumes ≥70 mL, which has important implications for patient management.…”

Early neurological stability predicts adverse outcome after acute ischemic stroke

“…Reperfusion was also an independent predictor of improving NIHSS score in multivariate analyses. These findings are in accord with prior studies demonstrating the robust clinical benefit of reperfusion (29,34). That said, it was not the only independent predictor of ΔNIHSS, suggesting that reperfusion status accounts for some, but not all of the variability in early neurological course.…”

The Importance of Considering Sex Differences in Translational Stroke Research

“…Two other studies with larger sample size (n=205 and n=81) on intra-arterial administration of tPA or urokinase did not find sex differences in recanalization rates [51, 52]. Of note, recanalization might not always lead to reperfusion and studies suggest that reperfusion may be a better predictor of infarct volume and clinical stroke outcome [53, 54]. Sex-specific effects of tPA have also been demonstrated when it is combined with other treatments.…”