Higher proceduralist stroke thrombectomy volume is associated with reduced inpatient mortality

Background: The aim of this study was to determine the impact of endovascular thrombectomy (EVT) proceduralist volume on in-hospital mortality in acute ischemic stroke (AIS) patients.

Methods: We performed a retrospective cohort study using the 2020 Florida State Inpatient Database, including adult patients who had a diagnosis of AIS and underwent EVT during the same admission. The primary study outcome was in-hospital death. We used Youden's Index to define an optimal threshold for number of EVTs/year/provider. Based on this cut-point, the cohort was dichotomized into low and high proceduralist volume groups. We fit logistic regression models to mortality in the full cohort, both as univariate analyses and after adjusting for covariates.

Results: Among 3143 AIS patients who underwent EVT, 1907 patients across 59 hospitals and 106 providers met our inclusion criteria. Among the providers, the median number of EVTs performed was 13.5 (IQR 7-25). The optimal cut-point was 17 EVTs. Demographics and comorbidities were similar between the cohorts. The high volume strata had a lower rate of in-hospital mortality (low volume 11.0% vs high volume 7.2%, P=0.005). After adjusting for potential confounders, high proceduralist volume remained significantly associated with lower odds of in-hospital death (OR 0.52, 95% CI 0.36 to 0.76, P=0.001). The difference in absolute risk of death was 4.8% (P=0.005).

Conclusions: We found that high proceduralist volume, defined by ≥18 EVTs/year, was associated with reduced in-hospital morality. Further research is necessary to understand the effects of proceduralist experience and benchmarks for technical proficiency in stroke care.