Introduction: Endovascular treatment of acute ischemic stroke (AIS) has evolved rapidly with the advent of mechanical devices such as the Mechanical Embolus Removal in Cerebral Ischemia (MERCI), Penumbra system, and Solitaire FR. We aim to study the national trend of utilization and outcome after endovascular intervention for patients with AIS with respect to technological changes.
Methods: We analyzed the Nationwide Inpatient Sample (NIS) to study clinical outcome of endovascular stroke therapy over three periods: 2004-2007 (post-MERCI), 2008-2011 (post-Penumbra), and 2012 (post-Solitaire). AIS patients who underwent endovascular clot retrieval were identified with ICD-9 codes. Morbidity and mortality were evaluated as a function of patient age and of concomitant thrombolytic agent administration.
Results: From 2004-2012, the number of AIS patients treated with endovascular intervention increased each year. The overall inhospital mortality in this cohort of patients decreased significantly from post-MERCI (25.2%), post-Penumbra (19.9%), to post-Solitaire period (17.1%, OR 0.733, 95% CI 0.666-0.808), although the rate of intracerebral hemorrhage increased slightly (0.10 vs. 0.17 vs. 0.20). In subgroup analyses based on age, the mortality decrease from 3 periods of technological changes was significant for patients older than 65 (27.3% vs. 23.2 vs. 17.5%, p<0.001), and trending towards significance for those younger than 65 (24.0 vs. 17.2 vs. 17.4, p=0.07). Multivariate logistic regression demonstrated that mortality rate for patients between 65 and 80 and patients older than 80 decreased significantly from post-Penumbra to post-Solitaire period (both p<0.001) after adjustment of gender, ethnicity, geographic location, and co-morbidities.
Conclusions: The utilization of endovascular thrombectomy in AIS patients increased steadily over time. The in-hospital mortality significantly decreased from post-MERCI (2004-2007), post-Penumbra (2008-2011), to post-Solitaire (2012) era, especially in patients with older age.
Patient Care: Our research provides "real-life" data collected from American hospitals regarding the improvement of clinical outcome over time in AIS patients who underwent endovascular intervention. Such improvement coincides with the technological advancement in the field and further demonstrate that, along with the newly published randomized trials, endovascular stroke therapy is a safe and effective treatment for certain AIS patients with careful selection criteria.
Learning Objectives: By the conclusion of this session, participants should be able to 1) describe the technological advances in different generation of mechanical thrombectomy device, 2) understand the effect of age on clinical outcomes after endovascular stroke therapy.