Improving mTICI2b reperfusion to mTICI2c/3 reperfusions: A retrospective observational study assessing technical feasibility, safety and clinical efficacy

The clinical correlates of the varying degrees of early hemorrhagic transformation of a cerebral infarct are unclear. We investigated the cohort of a randomized trial of thrombolysis to assess the early and late clinical course associated with different subtypes of hemorrhagic infarction (HI) and parenchymal hematoma (PH) detected within the first 36 hours of an ischemic stroke. We exploited the database of the European Cooperative Acute Stroke Study I (ECASS I), a randomized, placebo-controlled, phase III trial of intravenous recombinant tissue plasminogen activator in acute ischemic stroke. Findings on 24- to 36- hour CT were classified into 5 categories: no hemorrhagic transformation, HI types 1 and 2, and PH types 1 and 2. We assessed the risk of concomitant neurological deterioration and of 3-month death and disability associated with subtypes of hemorrhagic transformation, as opposed to no bleeding. Risks were adjusted for age and extent of ischemic damage on baseline CT. Compared with absence of hemorrhagic transformation, HI1, HI2, and PH1 did not modify the risk of early neurological deterioration, death, and disability, whereas, in both the placebo and the recombinant tissue plasminogen activator groups, PH2 had a devastating impact on early neurological course (odds ratio for deterioration, 32.3; 95% CI, 13. 4 to 77.7), and on 3-month death (odds ratio, 18.0; 95% CI, 8.05 to 40.1). Risk of disability was also higher, but not significantly, after PH2. Risk of early neurological deterioration and of 3-month death was severely increased after PH2, indicating that large hematoma is the only type of hemorrhagic transformation that may alter the clinical course of ischemic stroke.

Our aim was to detail revascularization results, including impact on outcome and mortality, in the Interventional Management of Stroke (IMS) II trial. IMS II was designed to obtain estimates of the efficacy and safety of reduced-dose intravenous recombinant tissue plasminogen activator (rtPA) followed by additional intra-arterial rtPA and low-energy sonography via the EKOS Primo Micro-Infusion Catheter at the occlusion in selected patients with ischemic stroke treated within 3 hours of onset. Revascularization outcomes were detailed and compared with modified Rankin Scale scores 0-2, mortality outcomes, and results from IMS I. Complete recanalization at 60 minutes occurred in 12 of 29 (41.4%) sonography microcatheter-treated occlusions. Complete recanalization was achieved at 2 hours or procedure end in 20/29 (68.9%) in the ultrasound catheter-treated group, and final thrombolysis in cerebral infarction (TICI) 2/3 reperfusion was achieved in 18/29 (62.0%) ultrasound-treated subjects. Fifteen-minute angiograms demonstrated some recanalization in 69/145 (46.7%) sonography microcatheter treatment intervals, compared with 39/111 (35.1%) in IMS I treatments in 23 subjects with reliable 15-minute angiograms (P = .046). Pooled IMS I-II data demonstrated that partial or complete recanalization occurred in 56/75 (74.6%) and good reperfusion (TICI 2/3) occurred in 46/75 (61.3%) of internal carotid artery T and M1 occlusions. Revascularization correlated with good outcome for TICI 2/3 reperfusion (P = .0004), TICI 2B/3 reperfusion (P = .0002), and arterial occlusive lesion 2/3 recanalization (P = .03). IMS II provides evidence that the EKOS Primo sonography microcatheter exhibits a trend toward improved recanalization of the occlusion compared with a standard microcatheter and again confirms the correlation between recanalization and reperfusion with good clinical outcome and reduced mortality.

Angiographic revascularization grading after intra-arterial stroke therapy is limited by poor standardization, making it unclear which scale is optimal for predicting outcome. Using recently standardized criteria, we sought to compare the prognostic performance of 2 commonly used reperfusion scales. Inclusion criteria for this multicenter retrospective study were acute ischemic stroke attributable to middle cerebral artery M1 occlusion, intra-arterial therapy, and 90-day modified Rankin scale score. Post-intra-arterial therapy reperfusion was graded using the Thrombolysis in Myocardial Infarction (TIMI) and Modified Thrombolysis in Cerebral Infarction (mTICI) scales. The scales were compared for prediction of clinical outcome using receiver-operating characteristic analysis. Of 308 patients, mean age was 65 years, and median National Institutes of Health Stroke Scale score was 17. The mean time from stroke onset to groin puncture was 305 minutes. There was no difference in the time to treatment between patients grouped by final TIMI (ie, 0 versus 1 versus 2 versus 3) or mTICI grades (ie, 0 versus 1 versus 2a versus 2b versus 3). Good outcome (modified Rankin scale, 0-2) was achieved in 32.5% of patients, and mortality rate was 25.3% at 90 days. There was a 6.3% rate of parenchymal hematoma type 2. In receiver-operating characteristic analysis, mTICI was superior to TIMI for predicting 90-day modified Rankin scale 0 to 2 (c-statistic: 0.74 versus 0.68; P<0.0001). The optimal threshold for identifying a good outcome was mTICI 2b to 3 (sensitivity 78.0%; specificity 66.1%). mTICI is superior to TIMI for predicting clinical outcome after intra-arterial therapy. mTICI 2b to 3 is the optimal biomarker for procedural success.