Abstract WP25: The Impact of Body Mass Index on Outcomes of Mechanical Thrombectomy for Acute Ischemic Stroke

Abstract

Background: Obesity is an established risk factor for acute ischemic stroke (AIS), but its impact on clinical outcomes and mortality after AIS remains controversial. In this study, we evaluate the association of body mass index (BMI) on outcomes after mechanical thrombectomy (MT) for large vessel occlusion acute ischemic stroke (LVOS). Methods: We reviewed our prospective MT database for LVOS between 2015 and 2018. BMI was analyzed as a continuous and categorical variable with underweight BMI <18.5, normal BMI 18.5-24.9, overweight BMI 25-29.9, and obese BMI>30. Multivariate analysis was used to determine predictors of outcome. Results: 335 patients underwent MT with 7 (2.1%) patients classified as underweight, 107 (31.9%) normal, 141 (42.1%) overweight, and 80 (23.9%) obese. Compared to normal weight (reference), obese patients had higher rates of hypertension and hyperlipidemia, while underweight patients had higher rates of previous stroke and presentation NIHSS. The time from symptom onset to puncture, procedural techniques, and reperfusion success (>TICI 2b) was not significantly different between BMI categories. There was a significant inverse linear correlation between BMI and symptomatic hemorrhagic. In patients with successful reperfusion (>TICI 2b), there was also a significant bell-shaped relationship between BMI and functional independence (mRS < 3) with both low and high BMIs associated with worse outcomes. In patients without post-procedural symptomatic hemorrhage, there was a significant linear correlation between BMI and inpatient mortality. Conclusion: In LVOS patients treated with MT, BMI is inversely related with post-procedural symptomatic hemorrhage. Yet in those whom reperfusion is achieved, both lower and higher than normal BMI were associated with worse functional outcomes. Thus, the obesity paradox does not appear to pertain to mechanical thrombectomy, although larger prospective studies are necessary.