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Response from the SAMMPRIS trial principal investigators regarding inaccuracies in this editorial
  1. Colin P Derdeyn1,
  2. David Fiorella2,
  3. Marc Chimowitz3
  1. 1Departments of Neurology and Neurosurgery, Mallinckrodt Institute of Radiology, Washington University, St Louis, Missouri, USA
  2. 2Department of Neurosurgery, Stony Brook, New York, New York, USA
  3. 3Department of Neurology, Medical University of South Carolina, Charleston, South Carolina, USA
  1. Correspondence to Dr Colin P Derdeyn, Mallinckrodt Institute of Radiology, Washington University, 510 South Kingshighway Blvd, St Louis, MO 63110, USA; derdeync{at}

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As the principal investigators for the Stenting and Aggressive Medical Management for the Prevention of Recurrent Ischemic Stroke (SAMMPRIS) trial,1 we are compelled to address a few inaccuracies regarding this study in the recent editorial by Dr Alexander.2

The first point is the patient population. The SAMMPRIS population was the right patient population to test. We had very good data from the Warfarin versus Aspirin for Symptomatic Intracranial Disease (WASID) trial that patients with recently symptomatic severe stenosis were at the highest risk for recurrent stroke.3 This high-risk population offered the best chance for showing a benefit with revascularization. Much of the criticism in the editorial has the benefit of hindsight. The hemodynamic versus embolic mechanisms for stroke may be important in defining groups that benefit from angioplasty in the future.4 This distinction does not matter for extracranial carotid disease as revascularization works regardless of the mechanism. It may matter for intracranial atherosclerotic disease. Finally, in designing a trial, there are always groups of patients that will not be included, such as the high-risk unstable patients described in the editorial. Our data do not address treatment of these patients one way or the other, and that should not be a criticism of the trial.

Second, the Wingspan stent was not used off-label in the trial. It is true that we used the stent under a Food and Drug Administration Investigational Device Exemption that was not the same as the Humanitarian Device Exemption (HDE) for the stent. This does not make the SAMMPRIS results ‘dubious’. SAMMPRIS conclusively showed that angioplasty and stenting for the high-risk WASID population was worse than aggressive medical management. Moreover, a subgroup analysis in patients who had failed antithrombotic therapy at the time of their qualifying event for SAMMPRIS (ie, those patients who met the HDE criteria) also showed that angioplasty and stenting was worse than aggressive medical management in these patients.5

Finally, there was never a policy that all 20 cases of angioplasty and stenting submitted for credentialing had to be with the Wingspan device, as stated by Dr Alexander. We required documentation of 20 consecutive intracranial angioplasty and/or stenting cases and accepted experience with similar devices.6 These cases and their outcomes were carefully reviewed by a credentialing committee composed of experienced neurointerventionists. The fact that interventionists with the least experience with Wingspan had similar event rates to those with the greatest experience indicates that this system identified a very capable group of neurointerventionists.7 In at least one of the carotid stenting trials mentioned by Dr Alexander, some interventionists were allowed to participate without the requisite experience as long as they were proctored during the procedure.8 Others were allowed in with as few as five total carotid angioplasty and stenting cases (with any device). This was not permitted in SAMMPRIS.

We agree wholeheartedly that we still have much to learn about this disease and its treatment.


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  • Contributors All authors contributed.

  • Competing interests None.

  • Provenance and peer review Not commissioned; internally peer reviewed.