Doyle, Karen

Introduction EXCELLENT (NCT03685578; Cerenovus) is a large, prospective, international, real‐world registry of endovascular clot removal in acute ischemic stroke (AIS) with EmboTrap as the first line mechanical thrombectomy (MT) device, which included collection and analysis of the retrieved thrombus material. Methods Between September 2018 and March 2021, 1000 “all‐comer” patients were enrolled at 34 global sites (27 US, 5 EU, 1 UK, 1 Israel) and treated according to standard of care at each center (with Embrotrap as first line). The study employed blind endpoint evaluation, including a core imaging lab and an independent 90‐day mRS assessment. Retrieved clot was collected per each MT maneuver from 538 subjects across 26 sites and clot analysis was performed by independent central labs blinded to clinical data. Results mITT population included 998 subjects. Mean age was 69.9±14.18 years (range 18–102), 51.8% (517/998) subjects were female and 9.9% (97/997) had a pre‐stroke mRS 3–5. Baseline NIHSS was 15.6±6.87 (range 0–36); 10.1% (82/815) subjects had a large core (ASPECTS 0–5); 5.8% (57/990) had posterior stroke; 56.3% (523/929) underwent MT ≤ 6hrs of onset and 38.1% (380/998) received IV‐tPA prior to MT. First pass eTICI 2c‐3 was achieved in 38.3% (377/984) and final 2b‐3 in 94.5 % (930/984; median number of passes = 1) of subjects. 90‐day mRS≤2 or ≤pre‐stroke was 46.9% (429/915) and 90‐day all‐cause mortality was 19.0% (175/921). The univariate analysis of clot components showed high red blood cell and low platelet content were significant predictors of good mRS outcome (p < 0.001 and 0.009) and negative predictors of 90‐day mortality (p < 0.001 and 0.017, respectively). Conclusions This large multi‐center, all‐comer cohort reflects the population undergoing thrombectomy today in a real world‐setting. Final angiographic, clinical and thrombus composition results, along with multivariate analysis of predictors of clinical outcomes, will be presented at the time of the conference.

Background: Understanding clot composition may allow for better technical planning and improved outcomes in mechanical thrombectomy (MT). We sought to correlate clot composition with reperfusion outcomes in MT. Methods: Clinical, imaging, and clot data from patients enrolled in the STRIP Registry from September 2016 to September 2020 were analyzed. Samples were fixed in 10% phosphate-buffered formalin and stained with hematoxylin and eosin and Martius Scarlett Blue. Percent composition, richness, and gross appearance were evaluated. Outcome measures included the rate of First-Pass Effect (mTICI2c/3, FPE) and the number of device passes. Results: A total of 1430 patients (mean age, 68.4±13.5years; median [IQR] baseline NIHSS,17.2 [10.5-23]; IV-tPA use, 36%; Stent-Retrievers [SR], 27%; Contact Aspiration [CA], 27%; Combined SR + CA, 43%) were included. The median [IQR] number of passes was 1 [1-2]. FPE was achieved in 39.3% of the cases. There was no association between percent histological composition or clot richness and FPE in the overall population. However, the combined technique resulted in lower FPE rates for RBC-rich (P<0.0001), platelet-rich (P=0.003), and mixed (P<0.0001) clots. Fibrin-rich and platelet-rich clots required a higher number of passes compared to RBC-rich and mixed clots (median, 2 and 1.5 vs.1, respectively, P=0.02). CA displayed a trend towards a higher number of passes with fibrin-rich clots (2 vs.1, P=0.12). By gross appearance, mixed/heterogeneous clots had lower FPE rates than red and white clots. Conclusion: Despite the lack of correlation between clot histology and FPE in the overall population, our study adds to the growing body of evidence supporting the notion that clot composition influences reperfusion treatment strategy outcomes. Additional studies are needed.

Introduction: EXCELLENT (NCT03685578) is a global prospective, multicenter, real-world registry of mechanical thrombectomy for stroke with the EmboTrap device as first line treatment which includes clot collection and analysis. Aim of the study: To report the rates of clinical outcomes and clot characteristics associated with first pass reperfusion in EXCELLENT. Methods: Per pass angiographic outcomes assessed by an independent core lab were available in 984 subjects Analysis of clot from 538 cases was performed by independent central labs blinded to clinical data. 90-day mRS assessment was blinded to subject data. Results: First pass reperfusion of mTICI 2b-3 (63.2%) and 2c-3 (38.3%) was significantly predictive of mRS 0-2 or ≤pre-stroke (p=0.011 and p=0.016) but not all-cause mortality at 90 days (p=0.080 and p=0.123, respectively). Further, mTICI 2c-3 in one pass was associated with a higher rate of mRS 0-2 or ≤pre-stroke vs. mTICI 2c-3 reperfusion in >1 pass, (55.5% and 45.1%, respectively, p=0.013) and a rate of all-cause mortality at 90 days of 14.6% vs. 19.8% (p=0.097). Full patient characteristics and clinical outcomes are shown in Table 1. Notable clot composition findings included: RBC (%, mean±SD): mTICI 2c-3, 1 pass 47.69±22.25, mTICI 2c-3, >1 pass 43.86±19.05, (p=0.088); fibrin: mTICI 2c-3, 1 pass 23.20±13.80, mTICI 2c-3 >1 pass 25.40 ± 13.52 (p=0.131); von Willebrand factor (VWF): mTICI2c-3, 1 pass 16.09±14.62, mTICI 2c-3, >1 pass 19.42±17.15 (p=0.038). Conclusions: First pass reperfusion in the EXCELLENT registry was associated with better clinical outcomes at 90 days. Clots retrieved with first pass reperfusion had higher RBC and lower fibrin and VWF content compared to those who achieved reperfusion at greater than one pass.