Patterns in the number of interventionalists for endovascular treatment of acute ischemic stroke in the US



      Endovascular thrombectomy (ET) has become the standard of stroke care for large vessel occlusion acute ischemic stroke (AIS) involving the anterior circulation. With continued eligibility expansion, the demand for neuro-intervention is growing. Current estimates indicate inadequate supply of interventionalists. However, there is limited data describing the number of interventionalists per hospital in the US, and correlations with outcomes.


      We used Medicare 100% sample datasets and included all AIS admissions from 2018 to 2019, using validated International Classification of Diseases, 10th Revision, Clinical Modification codes to identify AIS and comorbidities. We utilized National Provider Identifier codes to identify distinct interventionalists at the hospital. We examined outcomes at the hospital level, including percent of AIS treated with thrombolysis, percent of AIS with inpatient mortality, percent of AIS with discharge home, and percent of AIS with death within 30 days.


      Among 471,427 AIS admissions, 16,253 received ET over the 2-year period of the study. Only 683 of 4576 AIS-treating institutions provided ET (14.9%). These ET centers most frequently only had one interventionalist performing ET and were clustered in large metropolitan areas with high AIS volumes. As AIS volumes, ET volumes, and mean NIHSS scores increased, so did the number of interventionalists. With each additional interventionalist, there was an increased likelihood of poor outcomes including inpatient mortality, discharge home, and 30-day mortality.


      We confirmed a relative lack of neuro-interventionalists among US hospitals, with a concentration of interventionalists in urban, high-volume centers. The greater likelihood of poor outcomes associated with increasing number of interventionalists is likely due to increasing complexity and severity of cases at high-volume ET centers, but further study is needed.

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