December 12, 2019
Effect of BMI Evaluated in Outcomes of Endovascular Treatment for Acute Ischemic Stroke
December 12, 2019—A post hoc analysis of the MR CLEAN trial evaluated the association of body mass index (BMI) and outcomes after endovascular treatment (EVT) in acute ischemic stroke patients with large vessel occlusion (LVO) and assessed whether BMI affects the benefit of EVT. MR CLEAN is a multicenter randomized clinical trial of endovascular treatment for acute ischemic stroke in the Netherlands.
The analysis findings were published by France Anne Victoire Pirson, PhD, et al on behalf of the MR CLEAN investigators online ahead of print in Cerebrovascular Diseases.
According to the investigators, obesity is a well-known risk factor for vascular disease, but the condition’s impact on stroke outcomes has been disputed; several studies have shown that obesity is associated with better functional outcome after stroke. It is not known if obesity influences the benefit of EVT in stroke patients.
In this post hoc analysis, BMI was used as a continuous and categorical variable, distinguishing underweight and normal weight (BMI < 25), overweight (BMI 25–30), and obesity (BMI ≥ 30). The investigators used multivariable ordinal logistic regression analysis to estimate the association of BMI with functional outcome (shift analysis), assessed with modified Rankin Scale (mRs) at 90 days. The impact of BMI on EVT effect was tested by the use of a multiplicative interaction term.
As summarized in Cerebrovascular Diseases, the analysis was composed of 366 patients: 160 (44%) were underweight or normal weight, 145 (40%) were overweight, and 61 (17%) were obese.
The investigators reported the following:
- A multivariable analysis with BMI as a continuous variable showed a shift toward better functional outcome with higher BMI (mRS adjusted common odds ratio [aOR], 1.04; 95% confidence interval [CI], 1.0–1.09); additionally, mortality was inversely related to BMI (aOR, 0.92; 95% CI, 0.85–0.99).
- Safety analysis showed that higher BMI was associated with lower risk of stroke progression (aOR, 0.92; 95% CI, 0.87–0.99).
- Additional analysis showed no interaction between BMI and EVT effect on functional outcome, mortality, and other safety outcomes.
The study confirms the effect of obesity on outcome in acute ischemic stroke patients with LVO, meaning better functional outcome, lower mortality, and lower risk of stroke progression for patients with higher BMI; because no interaction was found between BMI and EVT effect, all BMI classes may expect the same benefit from EVT, concluded the investigators in Cerebrovascular Diseases.