Our objective is to determine the incidence and predictors of First Pass Effect within 30 min at a comprehensive stroke center

First pass effect (FPE) is an established metric of success of mechanical thrombectomy (MT). Recently, FPE within 30 minutes (FPE30) of groin puncture has been defined as a novel metric incorporating time as a dimension. We aim to determine the incidence and predictors of FPE30 at a comprehensive stroke center (CSC). 

We retrospectively analyzed MT data at a CSC. Demographic, clinical, procedural, and radiological data were collected and assessed by an independent interventional neurologist. FPE was defined as mTICI 2C-3 after one thrombectomy attempt and FPE30 was defined as FPE within 30 minutes of groin puncture. We performed univariate and multivariate analyses to identify predictors of FPE30. 

Of 274 MT patients, 24.8% had excellent reperfusion (mTICI 2C-3), and 19.0% experienced FPE. Amongst FPE patients, 82.7% had FPE30 and 17.3% had FPE>30 (FPE but after 30 minutes of groin puncture) (Figure). Mean time from puncture to reperfusion in FPE30 cohort was 18 +/-13 min and in FPE>30 cohort was 32 +/-15 min. Age and gender were comparable between FPE30 versus FPE>30 groups. Internal carotid occlusions were less common (7% vs. 33%, p=0.09) and radial access was more frequent (49% vs. 33%, p=0.4) in the FPE30 when compared to FPE>30 cohort. Rate if mRS 0-2 at 90 days was 34.9% in FPE30 and 33.3% in FPE>30 cohort. 

First Pass Effect within 30 minutes is observed in a majority of patients experienced FPE. Predictors of FPE< 30 may include internal carotid occlusion and femoral route of access. Further analyses are needed to confirm our findings.