Final Infarct Volume Is a Stronger Predictor of Outcome Than Recanalization in Patients With Proximal Middle Cerebral Artery Occlusion Treated With Endovascular Therapy

Abstract

This study represents a retrospective analysis of a prospectively acquired database comprising 562 consecutive patients with acuteBackground and Purpose-The rationale for recanalization therapy in acute ischemic stroke is to preserve brain through penumbral salvage and thus improve clinical outcomes. We sought to determine the relationship between recanalization, clinical outcomes, and final infarct volumes in acute ischemic stroke patients presenting with middle cerebral artery occlusion who underwent endovascular therapy and post-procedure magnetic resonance imaging.Methods-We identified 201 patients with middle cerebral artery occlusion. Patients with other occlusive lesions were excluded. Baseline clinical/radiological characteristics, procedural outcomes (including thrombolysis in cerebral infarction scores), clinical outcome scores (modified Rankin scores), and final infarct volumes on diffusion weighted imaging were retrospectively analyzed from a prospectively collected database. Favorable outcome is defined as 90-day modified Rankin score ≤2. Results-Successful recanalization (thrombolysis in cerebral infarction grade 2b or 3) was achieved in 63.2% and favorable outcomes in 46% of cases. Mean infarct volume was 50.1 mL in recanalized versus 133.9 mL in non-recanalized patients (P<0.01) and 40.4 mL in patients with favorable outcomes versus 111.8 in patients with unfavorable outcomes (P<0.01).In multivariate analysis, thrombolysis in cerebral infarction ≥2b, baseline National Institute of Health Stroke Scale, Alberta Stroke Program Early Computed Tomography scores, and age were identified as independent predictors of outcome. However, when infarct volumes were included in the analysis only final infarct volume and age remained significantly associated. Conclusions-Successful recanalization leads to improved functional outcomes through a reduction in final infarct volumes. In our series, age and final infarct volume but not recanalization were found to be independent predictors of outcome, supporting the use of final infarct volume as surrogate marker of outcome in acute stroke trials. (Stroke. 2012;43:3238-3244.)Key Words: acute stroke ◼ infarct volume ◼ interventional treatment ◼ stroke outcome

Leukoaraiosis Predicts a Poor 90-Day Outcome after Endovascular Stroke Therapy

“…21 Indeed, we and others have previously shown that leukoaraiosis severity is associated with a larger ischemic core, mismatch lost, and final infarct volume, supporting this hypothesis. 13,15,22 Indeed, subgroup analyses in patients with available follow-up imaging indicated that worse leukoaraiosis independently predicted larger infarct volumes.…”

Intra-Arterial Therapy and Post-Treatment Infarct Volumes

“…Previous studies have examined the association between post-treatment infarct volume (measured at 24-48 hours) and functional ability at 90 days as measured by the mRS. 8,9 Our results show that post-treatment infarct volume is a strong independent predictor of 90-day mRS. The mRS at 90 days is best predicted when information on acute treatment response (change in NIHSS from baseline to 24 hours) is available along with post-treatment infarct volumes.…”

“…Time to randomization was not a significant predictor of post-treatment infarct volume in our analysis, but we hypothesize that this is because of study design; imaging selection used in the ESCAPE trial (subjects selected using favorable imaging criteria independent of time from onset to randomization) may have contributed to these results. Stroke onset time is also imprecisely measured with many subjects either waking up after stroke onset or only last seen normal at a certain time.Previous studies have examined the association between post-treatment infarct volume (measured at 24-48 hours) and functional ability at 90 days as measured by the mRS. 8,9 Our results show that post-treatment infarct volume is a strong independent predictor of 90-day mRS. The mRS at 90 days is best predicted when information on acute treatment response (change in NIHSS from baseline to 24 hours) is available along with post-treatment infarct volumes.…”

“…We measured post-treatment infarct volume at 24 to 48 hours, but there remains a possibility of infarct growth after 24 to 48 hours. [8][9][10][11][12] Neither CT nor MRI has been compared with brain histology as methods measuring brain infarct in …”

“…We measured post-treatment infarct volume at 24 to 48 hours, but there remains a possibility of infarct growth after 24 to 48 hours. [8][9][10][11][12] Neither CT nor MRI has been compared with brain histology as methods measuring brain infarct in humans, and it is therefore not well known how meaningful are the inherent differences between brain CT and MRI for measuring discrete infarct volumes. In summary, our results support the primary results of the ESCAPE trial and show that the biological underpinning of the success of arterial recanalization and brain tissue reperfusion therapies is reduction in infarct volume.…”