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Study testing late clot removal in stroke is important but not a “breakthrough” or “paradigm shift”

Landmark study may impact standard stroke treatment guidelines

Our Review Summary

This news release from Emory University describes findings of a randomized clinical trial that showed positive outcomes among almost half of stroke patients whose brain blood clots were removed well outside the time frame of six hours currently recommended by stroke experts.

The release properly discloses that the study was funded by a company that makes the clot removing device and quotes investigators from one of the participant investigators not at Emory.

The release could have been stronger had it disclosed details about the patients (such as age, and their co-occurring conditions, race, gender); the size of the population of stroke victims in the U.S. likely to benefit from “late” clot removal; and limitations of the study (e.g. follow up was for 90 days, not long term). Some details on which stroke victims are considered eligible for clot removal within six to 24 hours and the costs of the clot removal procedure itself would have been helpful.


Why This Matters

Disability from stroke is a major cause of suffering and high health care costs in the United States and elsewhere, and despite advances in technology (clot removal devices) and clot-busting drugs, its prevention has long depended on how fast a stroke patient can make it to a hospital for treatment. The six-hour window long thought to be the maximum time in which clot removal technologies could save brains and lives has meant that individuals unlucky enough to have a stroke in remote locations, or in bad weather, for example, stood little chance of enough recovery to lead independent lives. Thus, the results of rigorous studies like the one described in the release — it was stopped early because of the positive outcomes — are exceptionally newsworthy, and important for the public to know about.


Does the news release adequately discuss the costs of the intervention?

Not Satisfactory

Although preventing disability in stroke patients will clearly save health care dollars, it’s also possible that the additional costs of imaging to identify patients eligible for clot removal after six hours will add to health care costs. But this issue is not addressed. The release also contains no information about the potential number (and overall percentage) of stroke patients who might benefit from late clot removal, further obscuring the potential savings in dollars as well as disability.

Does the news release adequately quantify the benefits of the treatment/test/product/procedure?


The release does an adequate job of comparing the randomized groups (late clot retrieval versus medication), although it could have offered much more information about how the study defined patients whose damaged brain area was considered “small” enough to qualify for late clot removal.

Does the news release adequately explain/quantify the harms of the intervention?

Not Satisfactory

The release doesn’t mention any specific harms from either approach, nor what the rate of adverse effects was in either group. It’s not enough to state only that there was no difference.

The release noted that there was “no difference in mortality or other safety end points between the two groups of patients” in the study (those undergoing clot removal and those getting medical only). But the release could have been much clear about specific “safety end-points,” complications of both the clot-removal procedure and drug therapy; and certainly more information about residual disability in both patient groups.

Does the news release seem to grasp the quality of the evidence?

Not Satisfactory

This is the category where a “ding” seems needed. The reader will not learn enough about the patient selection criteria, the patients themselves, the specifics about imaging requirements and so on to understand or appreciate why this study is considered a potential “landmark” in stroke treatment.

While this was a randomized trial, it was a non-blinded non-placebo-controlled one. The fact that the patients in the clot removal group knew they were getting extra treatment may have introduced bias. Limitations such as this should have been mentioned in the release, but weren’t.

Does the news release commit disease-mongering?


No mongering here.

Does the news release identify funding sources & disclose conflicts of interest?


The funding source — a device manufacturer — was disclosed.

Does the news release compare the new approach with existing alternatives?


Readers of the release will get a general and adequate idea of the relative lack of options open to stroke victims who arrive at a hospital after the six-hour window considered optimal for mechanical clot removal. The alternative is not doing the procedure for late arrivals which is fairly clear from the release.

Does the news release establish the availability of the treatment/test/product/procedure?


In this case, availability has to do with whether hospitals offer this procedure. Since the procedure is already part of standard practice we’ll rate this Satisfactory, even though it’s not explicitly stated.

Does the news release establish the true novelty of the approach?


The release might have noted that previous research had suggested that some extension of the six-hour timetable for optimal clot removal was possible, even for medical therapy. But overall, the release makes clear why and how this trial was novel.

Does the news release include unjustifiable, sensational language, including in the quotes of researchers?

Not Satisfactory

Terms like “breakthrough” and “paradigm shift” are over-the-top for these findings.  While the release provides good supporting data, readers should remember that the study was a non-blinded, non-placebo controlled trial and given what we have learned from the ORBITA trial on cardiovascular stenting which has gained so much attention recently, even intervention therapies need a placebo control.

Total Score: 6 of 10 Satisfactory


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