The fourth-leading cause of death in the U.S. is stroke—approximately 800,000 people have a stroke each year, and about 130,000 of them die from it. About 9 in 10 strokes result from a clot blocking an artery in the brain. If blood flow isn’t restored quickly, brain tissue is damaged or destroyed, and functions like movement, speech and cognition are crippled.
You would think that taking out these clots with a device would be far superior to the drip-drip-drip of clot-busting drugs administered through an intravenous line. But alas, the studies are not showing that the aggressive methods work any better than the old IV treatment.
In recent years, an increasingly popular stroke treatment has been used to clear the artery blockage mechanically by inserting a catheter or tube into the brain artery to pull it out. The previous standard treatment was to administer clot-busting drugs (called “thrombolytics”) through an IV -- as long as patients were seen within a few hours of when their symptoms began. (See our blog about how long you can wait to get clot-busting drugs.) Timing is key because giving the drugs too late can cause uncontrolled bleeding, and the damage from the blocked artery to sensitive brain tissue may already be done..
But, as reported earlier this month by the Washington Post, three long-awaited studies show that the more invasive mechanical removal of a brain blood clot does not have a better outcome than the older drug treatment. And it’s significantly more expensive.
When the study results were presented at a medical conference, the paper reported, the attendees were shocked—many of them had been using the newer, more aggressive procedure since the FDA approved it for use in the brain in 2004. Early trials of the “endovascular treatment,” or clearing the clot by using a catheter to snag or and pull it out, had shown good results for clots elsewhere in the body. But the three studies reported earlier this month in the New England Journal of Medicine (here and here ) show something different for the brain procedure.
Doctors expected that endovascular treatment would do for stroke patients what it has done for heart attack patients. Treating their blockages with angioplasty (inflating a tiny balloon inside a blocked artery to open it up) and stents (inserting a tiny piece of tube to ensure the artery remains open) are demonstrably more effective than giving clot-dissolving drugs through a vein in the arm.
But when it comes to clots, it appears that a brain is not a heart.
The National Institute of Neurological Disorders and Stroke (NINDS) sponsored two of the trials. One took eight years to complete, according to The Post, because it was so difficult to enroll patients willing to take the chance that they would be randomly assigned to get the older treatment. One study had permission from 30 hospitals but found only 22 willing to participate. More than 10 other hospitals were invited to join the trial but declined because their neurologists were convinced the catheter treatment was better.
Endovascular treatment, according to The Post, costs about $23,000; the intravenous thrombolytics cost about $11,000. So it’s good that an expensive, invasive procedure has been shown to have no benefit over a less expensive approach, right?
Yes, but … Many doctors believe that the newer clot-retrieving devices work better than the ones used in the three trials, and because the procedure was shown to be no more dangerous than IV thrombolytics, they might continue using it, assuming that outcomes can only get better.
Maybe they will, and for now, insurance companies and Medicare cover the endovascular procedure. But as Walter Koroshetz, deputy director of NINDS, told The Post, “The payers may look at this and wonder if they should continue paying for these procedures. If it gets to that point, then clearly things will change.”
In the largest of the three trials, all patients got the IV clot-dissolving drug tPA within three hours of the start of stroke symptoms. Half got an imaging study that examined brain arteries to see whether a blockage remained. If it did, the doctors employed an endovascular procedure. The other half of the patients got the standard drugs, but no endovascular procedure. Forty-one in 100 of the endovascular group recovered completely in the endovascular group; among those who got only the drugs, 39 in 100 recovered completely. Statistically, that’s a tie.
The number of patients who died within three months also was essentially the same—19 versus 22 for the respective groups.
Another study involved 362 stroke patients. After three months, 35 in 100 from the tPA group were alive without any disabilities; 30 in 100 from the endovascular group had that status. Again, that is not a significant statistical difference.
The third study was more complicated. It randomly assigned 118 patients within eight hours of the start of their strokes to receive only the drug treatment or clot removal with a catheter device. They also got CAT or MRI scans to see whether they had a large or small amount of brain tissue still alive and salvageable. Removing the clot with a device was no better than standard care in either group, whether patients had a lot or a little viable brain tissue.
Apart from raising questions about the best stroke treatment and the best use of medical resources in stroke care, The Post noted that the studies demonstrated how difficult is to test treatments once they’re in widespread use: “History is replete with treatments … and devices … used routinely before being shown to be harmful or of little value.”
And now we’re left to wonder if this accepted but now questionable treatment will continue to be used because of momentum, insurance compensation or because the newer generation of devices might be measurably better. Is any of those a compelling reason?
Not in our estimation. Sometimes you just have to accept that what looked good turned out to be the same—only more expensive and invasive.