Three long-awaited studies have shown that mechanically removing a blood clot from a stroke patient's brain is no more useful than the older treatment of giving an IV dose of a clot-dissolving drug to the whole body.
The results of the clinical trials, presented this week at a meeting in Hawaii, shocked and surprised stroke physicians. Many had already adopted the more aggressive strategy over the last decade.
"For the stroke field this is a really big deal," Walter Koroshetz, deputy director of the National Institute of Neurological Disorders and Stroke, said of the findings, which were presented at the International Stroke Conference in Honolulu.
The institute paid for two of the trials, one of which cost $27 million. One study took eight years to complete because it was so difficult to enroll patients willing to take the chance they'd be randomly assigned to get the older treatment.
Practitioners hoped that "endovascular treatment," in which a catheter is threaded into a blocked artery and the clot pulled out, would do for stroke patients what it has done for heart attack patients. In them, going after clots with angioplasty balloons and stents is clearly more effective than giving clot-dissolving drugs through a vein in the arm.
"We did this study with the strong expectation that we would find a positive benefit. We were surprised," said Joseph P. Broderick of the University of Cincinnati Neuroscience Institute, who headed one of the studies.
Whether the findings will cause physicians to abandon the practice is uncertain.
Insurance companies and Medicare, the health insurer for the elderly, already cover the endovascular procedure. It costs about $23,000 compared with $11,000 for acute stroke treatment using intravenous clot-dissolving ("thrombolytic") drugs.
Further, many practitioners believe that newer clot-retrieving devices work better than the ones used in the three trials. Because endovascular procedures were shown to be no more dangerous than IV thrombolytics, physicians may continue to perform it and assume the outcomes can only get better.