Abstract 2: Outcomes After Endovascular Stroke Therapy in High Versus Low Volume Centers

Abstract

Background: Given the time-sensitivity of endovascular stroke therapy (EST), an increased availability of these treatments to lower-volume centers may improve patient outcomes. However, clinical trials demonstrating efficacy of EST were performed at larger volume centers, and our understanding of outcomes at lower volume centers is lacking. Methods: Using validated diagnosis codes from administrative data on all discharges from hospitals in Florida (2005-2016), and New York (2006-2014) we identified patients with acute stroke treated with EST. Primary endpoint was good outcome defined as discharge home without intracerebral hemorrhage. Descriptive statistics were used to calculate the number of EST performed. Multivariate logistic regressions adjusted for age, sex, and comorbidities were used to evaluate the association between year of treatment and hospital volume with outcome. Results: Among 5,699 patients (at 439 hospitals) treated with EST, median age was 72[60-81], 52% were female, and 54% received IV tPA. Annual EST procedures increased from 158 in 2007 to 423 in 2010 to 925 in 2014, as did the number of hospitals performing EST, from 30 in 2007 to 50 in 2010 to 68 in 2014. During the study period, an increasing proportion of total EST procedures were performed at lower volume centers ( Figure 1a ). Adjusting for age and comorbidities, the likelihood of good outcome increased yearly (OR 1.1 [1.05 -1.14]). Adjusting for age, comorbidities and year of treatment, increasing annual hospital EST volume was associated with increasing likelihood of good outcome ( Figure 1b ). Conclusions: In two large and diverse states, clinical outcomes with EST improved over time. Higher volume centers performed better than lower volume centers, a finding that persisted despite the overall trend towards improvement. These findings support the need for further study on the efficacy of EST outside of specialized centers.