Objective:

To determine the relationship between procedure volume for MT and in-hospital outcomes in acute ischemic stroke patients in the United States.

Background:

Hospitals with higher procedure volume are more likely to have lower rates of death or disability, with most neurovascular surgical and endovascular procedures. The volume of mechanical thrombectomy (MT) performed at hospitals is used as one of the criteria for advanced-level designation for stroke care.

Design/Methods:

We analyzed the nationally representative data from the Nationwide Inpatient Sample (NIS) from 2016 to 2020. The hospitals were grouped into quartiles based on the volume of MT procedures performed within the calendar year. We compared the rates of routine discharge/home health care (excluding those with palliative care), in-hospital mortality, and post-treatment intracranial hemorrhage (ICH) between the quartiles after adjusting for potential confounders.

Results:

In the logistic regression analysis, the odds of post-procedure ICH increased to 1.81 (p<0.001), 1.84 (p<0.001), and 1.98 (p<0.001) among the quartiles from lowest to highest procedural volumes after adjusting for potential confounders including clinical severity makers. The odds of home discharge/self-care decreased to 0.66 (p<0.001), 0.60 (p<0.001), and 0.63 (p<0.001) among the quartiles from lowest to highest procedural volumes. The odds of in-hospital mortality increased to 1.92 (p<0.001), 1.99 (p<0.001), and 1.84 (p<0.001) among the quartiles from lowest to highest procedural volumes.

Conclusions:

We observed a paradoxical relationship between adverse outcomes and procedure volume of MT at the hospital, presumably due to the higher severity of acute ischemic stroke at high-volume hospitals.