American Heart Association

Monthly Archives: May 2019

Author Interview: Drs. Thabele (Bay) Leslie-Mazwi, MD, and Gregory W. Albers, MD, on “DEFUSE 3 Non-DAWN Patients: A Closer Look at Late Window Thrombectomy Selection”

Dr. Thabele (Bay) Leslie-Mazwi, left, and Dr. Gregory W. Albers

Dr. Thabele (Bay) Leslie-Mazwi, left, and Dr. Gregory W. Albers

An interview with Dr. Thabele (Bay) Leslie-Mazwi, MD, Director of Endovascular Stroke Services, Massachusetts General Hospital; Assistant Professor of Neurology, Harvard University; and Dr. Gregory W. Albers, MD, Director, Stanford Stroke Center; Professor of Neurology, Stanford University.

Interviewed by Kristina Shkirkova, BSc, Doctoral Student in Neuroscience, Department of Neurosurgery, Zilkha Neurogenetic Institute, University of Southern California.

They will be discussing the article “DEFUSE 3 Non-DAWN Patients: A Closer Look at Late Window Thrombectomy Selection,” published in the March 2019 issue of Stroke.

Ms. Shkirkova: Please briefly summarize the design and findings of your study.

Drs. Leslie-Mazwi and Albers: We evaluated DEFUSE 3 patients who would have been excluded from the DAWN trial based on DAWN eligibility criteria, with the goal of assessing treatment effect in that DEFUSE 3 subgroup (DEFUSE 3 Non-DAWN). The main reasons for DEFUSE 3 Non-DAWN were NIHSS 6-9, core too large (based on age and volume of established infarct), and mRS of 2. Patients with mRS 2 were included with the NIH stroke scale 6-9 group, as detailed in our paper, and so we analyzed the DEFUSE 3 Non-DAWN patients NIHSS 6-9 and core-too-large patients to assess treatment effect in that subgroup.

Patients with pretreatment core infarct volumes <70ml but too large for inclusion by DAWN criteria demonstrated robust benefit from endovascular therapy. Data supporting a beneficial treatment effect across the full range of NIHSS scores was documented in the entire DEFUSE 3 population. In our small subgroup of patients with NIHSS 6-9, we found a trend towards benefit.

Prehospital Transfer Tool for Stroke Patients: Simplifying Complex Decisions

Elena Zapata-Arriaza, MD
@ElenaZaps

Venema E, Lingsma HF, Chalos V, Mulder MJHL, Lahr MMH, van der Lugt A, et al. Personalized Prehospital Triage in Acute Ischemic Stroke: A Decision-Analytic Model. Stroke. 2019;50:313–320.

Delay in the administration of required treatment in ischemic stroke can worsen the patient’s functional prognosis. Which patient needs direct transfer to a primary stroke center or to an intervention center is still a challenge in decision making.

To determine optimal prehospital transportation strategy, the authors performed a decision – analytic model. As described in Figure 1, this model starts with the initial decision of transportation to the primary stroke center or to the nearest endovascular-capable intervention center. The benefit of direct transportation to the intervention center was defined as the average amount of quality-adjusted life years (QALYs) gained by this strategy (difference of >0.02 QALYs (=1 week in full health) was considered clinically relevant). The short-run model calculates the probability of every possible pathway and the associated distribution of the modified Rankin Scale (mRS) score after 3 months. It takes into account driving times, in-hospital workflow characteristics, and time-dependent treatment effects. In each annual cycle of the following Markov model, patients can remain in the same health state or die. These probabilities are based on the age and sex-dependent annual mortality rates, adjusted for previously reported death hazard rate ratios of stroke patients.

Schematic overview of the model structure.

Figure 1. Schematic overview of the model structure. The decision node is represented with a square. The circles represent chance nodes, the circles marked with an M represent Markov models and the triangles represent terminal nodes. EVT indicates endovascular treatment; IVT, treatment with intravenous thrombolytics; and LVO, large vessel occlusion.