Joseph Broderick, MD, Research Director at the UC Neuroscience Institute, was in the spotlight last week as the Principal Investigator of an international clinical trial that compared outcomes of stroke patients who received a clot-dissolving drug (tPA) through an IV and those who also received endovascular therapy. The endovascular treatment involved either delivering tPA directly to the clot via a catheter threaded up from the groin to the brain, or using a catheter and an FDA-approved device to actually retrieve the clot.
The clinical trial, the Interventional Management of Stroke III (IMS III), found that patients who received the high-tech endovascular treatment fared no better than those who received tPA through an IV, although the safety of the two approaches was very similar. The trial disappointed stroke specialists who had sought to provide a new solution to the problem of stroke caused by a blockage in major arteries supplying oxygen-rich blood to the brain.
Dr. Broderick, the Albert Barnes Voorheis Professor and Chair of UC’s Department of Neurology and Rehabilitation Medicine, authored the study, which appeared in the New England Journal of Medicine. He discussed the study and its ramifications with multiple media outlets, including the New York Times, the Los Angeles Times and the Washington Post, at the International Stroke Conference 2013 last week in Honolulu.
The study will likely change how some stroke patients are treated at the UC Neuroscience Institute, one of four institutes of the UC College of Medicine and UC Health. The majority of patients will continue to be treated with tPA through an IV, without additional endovascular care. However, a subset of patients — those with large clots in large arteries — will strongly be considered for treatment with endovascular methods.
“Our study found that patients who have occlusions of the distal internal carotid artery did poorly with IV tPA and better with an endovascular approach, although the number of patients in that particular subgroup was small,” Dr. Broderick said.
Stroke patients may also benefit from two additional developments. The first is the UC Stroke Team’s effort to start endovascular therapy sooner, so as to maximize its benefits. “We have made efforts to minimize the time to start endovascular therapy since patients treated earlier tended to do better,” Dr. Broderick said. “We need to do an even better job with this.”
The second development involves improvements in the clot-retrieval devices themselves. “I think the new generation of devices is clearly better in opening arteries than what we had for most of the IMS III study,” said Andrew Ringer, MD, Director of the Division of Cerebrovascular Surgery and Professor of Neurosurgery & Radiology at UC. “I’ve seen a big difference in my own cases.”
Dr. Ringer and his colleagues at the Endovascular Neurosurgery Research Group, whose 20-plus members include the Mayo Clinic, Cornell University and the University of California, San Diego, have collected data on the effectiveness of a new FDA-approved flow-restoration device known as the Solitaire. A multi-center retrospective analysis of the self-expanding stent retriever was recently accepted by a peer-reviewed neurosurgical journal.
Dr. Broderick agreed that the newer devices open arteries better than those studied in the IMS III trial. A lingering question, however, is whether these improvements “will translate into better clinical outcomes for patients compared to IV tPA or standard therapy in patients who are beyond the tPA treatment window of 3 to 4 ½ hours.”
One thing is certain: the UC Stroke Team will continue to be at the center of international research into the best methods for treating patients who suffer acute stroke. “We remain very eager to participate in trials that test the combined tPA/endovascular and IV tPA alone approaches,” Dr. Broderick said. “We are participating in the Therapy Trial, which uses one of the new stent-retriever devices as well as a device that aspirates the clot. “We are also working on our next trial designs to improve rapid opening of brain arteries in acute stroke. These trials will include a combination of medications and advances in new mechanical devices.”
Pooja Khatri, MD, Associate Professor of Neurology and a neurologist at the UC Neuroscience Institute, is the medical principal investigator for the Therapy Trial, a multi-site U.S. study.