SGEM Xtra: Walk of Life – Thrombolysis for Acute Ischemic Stroke

Date: February 18th, 2019

Guest Skeptic: Dr. Shahriar Zehtabchi is a tenured professor and Vice Chair of Academic Affairs in the Department of Emergency Medicine at SUNY Downstate Medical Center & Kings County Hospital. He has been teaching evidence-base medicine for many years and currently is the editor-in-chief of the EBM website TheNNT.com. Shahriar also serves as an editorial board member and associate editor for Academic Emergency Medicine journal.

Dr. Shahriar Zehtabchi

Shahriar and I discussed the following:

The NNT and NNH as a concept
How to use the NNT/NNH to communicate with patients
Weaknesses of the NNT
What topics are covered on TheNNT.com and how they are selected
Their peer review process for quality control
Whether or not they have a policy to identify conflicts of interest
Dr. Zehtabachie's role as editor-in-chief

Guest Skeptic: Dr. Eddy Lang is a Professor and Department Head for Emergency Medicine Cumming School of Medicine, University of Calgary, Scientific Director Emergency Strategic Clinical Network and BEEM faculty member.

TheNNT.com updated their website January 11th, 2019 changing the recommendation of tPA for acute stroke from RED (no benefit) to GREEN (benefit > harms). Eddy was the lead author of the new recommendation and when it was posted it got the twitterverse very excited.

Dr. Eddy Lang

I reached out to Dr. Hoffman to discuss this change.  Then Eddy was invited to come on the SGEM to discuss why the change was made.

Eddy and I talked about the following:

My stated position on thrombolysis for acute CVA
His impression of the twitter storm
His stated position on thrombosis for acute CVA and synopsis of the evidence
Why he picked Dire Straights the Walk of Life as the theme music
The claim that the modified Rankin Scale (mRS) is reliable and validated
Limitations/weaknesses of the IST-3 Trial
GRADE Methodology
Inclusion and exclusion of different thrombolytic molecules in SRMAs
Various guidelines
Emberson et al SRMA from the Lancet
Why they changed the recommendation from RED to GREEN
The claim that time is brain
Stroke mimics
Thrombolysing patients without strokes (mimics)
Need for replication of trials in medicine
The ethics of replicating the NINDS trial
What Eddy says to patients/family at the bedside
The impact of conflicts of interest in the production and interpretation of the literature

Each of us will have different levels of evidence that will convince us to change our practice. I respect that two people can look at the same literature and come to a different conclusion. The burden of proof is on those making the positive claim that tPA results in a net patient-oriented benefit in acute ischemic stroke. In my opinion, the burden of proof has not been met and I remain skeptical. I am happy to change my mind if presented with stronger evidence.

Remember to be skeptical of anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine.

Additional Resources:

SketchyEBM - Knowing NNT
Chiong et al. Testing the Presumption of Consent to Emergency Treatment for Acute Ischemic Stroke. JAMA 2014
Banks and Marotta. Outcomes Validity and Reliability of the Modified Rankin Scale: Implications for Stroke Clinical Trials. A Literature Review and Synthesis. Stroke 2007 
Tsivgoulis et al. Safety of intravenous thrombolysis in stroke mimics: prospective 5-year study and comprehensive meta-analysis. Stroke 2015
Kamal et al. Improving Door-to-Needle Times for Acute Ischemic Stroke: Effect of Rapid Patient Registration, Moving Directly to Computed Tomography, and Giving Alteplase at the Computed Tomography Scanner. Circ Cardiovasc Qual Outcomes 2017
Harris et al. Treatment of Stroke in Canadian Emergency Departments: Time to be Leaders. CJEM 2017
Kamal et al. Good is not Good Enough: The Benchmark Stroke Door-to-Needle Time Should be 30 M...