When a blood clot blocks a blood vessel in the brain, the area of the brain it supplies is injured by the loss of oxygen and nutrients. This is called an ischemic stroke. One of the ways doctors treat ischemic stroke is by pulling the blood clot out of the blood vessel. They do this by threading a wire through blood vessels, starting at the leg or the arm until it gets to the clot in the brain. At that point the doctor either uses a snare or suction to grab the clot and pull it out of the body. This treatment is called endovascular thrombectomy (EVT).
EVT is one of the most effective treatments in the history of medicine. It reduces death and disability in two out of every five patients who have a stroke because of a blockage in a large blood vessel in the brain. However, the studies that led to FDA approval of these devices excluded patients who had an already existing disability before they had their stroke. Therefore, no one really knows what the benefits and risks of EVT are in people who have a preexisting disability at the time of their stroke, and doctors vary in their opinions. Because nearly 30 percent of patients with acute ischemic stroke have a preexisting disability, understanding the effects of EVT in this patient population is very important.
In this study, the research team will compare the risks and benefits of EVT to medical management (no EVT) in ischemic stroke patients who have a blockage in one of the large blood vessels in the brain and have a moderate-to-severe disability prior to their stroke. The study will be conducted at 12 sites across the United States and will enroll 1060 patients over 4 years. The patients will be selected for enrollment if they are admitted to the hospital for an ischemic stroke due to an occlusion in the large blood vessel in the brain. Treatment of this blockage with EVT or no EVT will be provided as routine medical care. Because doctors vary in their opinion about what works best, the doctors and the patients will decide together what treatment they would like before the researchers get involved. The type of treatment the patient receives will not be affected in any way by the research. After the treatment is completed, the patients or their legally authorized representative(s) will be asked if the study team can collect information on their ability to get around and function before their stroke and at 90-days after their stroke. When all of the data have been collected, the study team will compare the patients who got EVT to the patients who did not. They will also analyze the data to see if EVT works differently for some patients with certain preexisting disabilities than for others.
Throughout the study, the investigators will work closely with representatives of patients and representatives of the doctors and nurses who care for them to ensure that robust, patient-centered study results are generated.