National trends in utilization and outcomes of endovascular treatment of acute ischemic stroke patients in the mechanical thrombectomy era.

BACKGROUND AND PURPOSE: Because several new devices for mechanical thrombectomy have become available, the outcomes of patients undergoing endovascular treatment for acute ischemic stroke are expected to improve in the United States. We performed this analysis to evaluate trends in utilization of endovascular treatment and associated rates of death and disability among acute ischemic stroke patients over a 6-year period, including further assessment within age strata.

METHODS: We obtained data for patients admitted to hospitals in the United States from 2004 to 2009 with a primary diagnosis of ischemic stroke using a large national database. We determined the rate and pattern of utilization, and associated in-hospital outcomes of endovascular treatment among ischemic stroke patients and further analyzed trends within age strata. Outcomes were classified as minimal disability, moderate to severe disability, and death based on discharge disposition and compared between 2 time periods: 2004 to 2007 (post-MERCI) and 2008 to 2009 (post-Penumbra) approvals

RESULTS: Of the 3,292,842 patients admitted with ischemic stroke, 72,342 (2.2%) received intravenous thrombolytic treatment and 13 799 (0.4%) underwent endovascular treatment. There was a 6-fold increase in patients who underwent endovascular treatment (0.1% of ischemic strokes in 2004 vs 0.6% in 2009; P<0.001), with the patients aged≥85 years having the lowest rate of utilization (0.2%). The rates of intracranial hemorrhage remained unchanged throughout the 6 years. In multivariate logistic regression analysis, after adjusting for age, gender, presence of hypertension, congestive heart failure, renal failure, and secondary intracranial hemorrhages, there was no difference in the rate of minimal disability between the 2 study intervals (2004-2007 vs 2008-2009; odds ratio, 0.8; 95% confidence interval, 0.7-1.04; P=0.11). Mortality decreased while moderate to severe disability increased for patients treated during 2008 to 2009 (odds ratio, 0.7; 95% confidence interval, 0.6-0.9; P=0.007; and odds ratio, 1.4; 95% confidence interval, 1.2-1.7; P=0.0002).

CONCLUSIONS: There has been a significant increase in the proportion of acute ischemic stroke patients receiving endovascular treatment over the 6 years and reduction in in-hospital mortality. Our results highlight the need to implement endovascular techniques in a balanced manner across various age groups that also results in the reduction of disability in addition to mortality.