Research Highlights:

  • Mechanical clot removal alone may be as effective as combining it with intravenous (IV) clot-busting medications for stroke patients.   
  • Mechanical clot removal alone reduced the risk of brain bleeding in this Japanese study.

Embargoed until 11:15 a.m. Pacific Time/2:15 p.m. Eastern Time, Friday, Feb. 21, 2020

LOS ANGELES, Feb. 21, 2020 – Skipping IV clot-busters and using mechanical clot removal alone for strokes may be just as good as the combination of both treatments, with less risk of brain bleeding, according to late breaking science presented today at the American Stroke Association’s International Stroke Conference 2020. The conference, Feb. 19-21 in Los Angeles, is a world premier meeting for researchers and clinicians dedicated to the science of stroke and brain health.

Using both therapies was previously reported to improve outcomes in acute stroke patients with large vessel occlusion. However, clot-busters could cause bleeding in the brain, and no studies have looked at mechanical clot removal alone without alteplase, the most commonly administered IV clot-busting medication, within 4.5 hours.

In a Japanese, multicenter, prospective, randomized trial, about 200 stroke patients (average age 74; 62% men) were assigned to either mechanical clot removal alone or the combination of IV clot-busters and mechanical clot removal. At 90 days, favorable outcomes, based on disability level, were similar: 59% for those who received clot removal alone and 57% for those who received the combination approach. There was no difference in death rates between the two groups. However, the rates of brain bleeding within 36 hours was significantly lower for the mechanical clot removal group than for the combination treatment group (34% vs. 50%, respectively).

“We feel that giving alteplase to dissolve clots is not necessary, and mechanical clot removal can be performed immediately,” said Kentaro Suzuki, M.D., Ph.D., lecturer in the department of neurology at Nippon Medical School Hospital in Japan. “If we skip alteplase, we can perform mechanical thrombectomy with low risk of bleeding.”

Suzuki noted that five ongoing trials including this study are investigating the optimal approach for stroke patients.

“Current recommendations from the American Heart Association/American Stroke Association recommend using intravenous therapy within the 4.5 hour-time window and then treating with mechanical clot removal, if appropriate,” said Mitchell S. V. Elkind, M.D., M.S., FAHA, FAAN, president elect of the American Heart Association, past chair of the Advisory Committee of the American Stroke Association — a division of the American Heart Association and professor of neurology and epidemiology at Columbia University New York and attending neurologist at Columbia University Medical Center of the New York-Presbyterian Hospital.

“The best strategy is usually to treat with [alteplase] . . . and then if the patient is eligible, the patient goes for endovascular therapy as well,” Elkind said. “But [we] don’t skip that initial step because sometimes the endovascular therapy gets delayed or doesn’t occur for some reason or another.”

The list of study authors and disclosures are available in the abstract. The study was partially funded by The Japanese Society for Neuroendovascular Therapy.

Additional Resources:

Statements and conclusions of study authors that are presented at American Stroke Association scientific meetings are solely those of the study authors and do not necessarily reflect Association policy or position. The Association makes no representation or warranty as to their accuracy or reliability. The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and device corporations are available at

The American Stroke Association’s International Stroke Conference (ISC) is the world’s premier meeting dedicated to the science of stroke and brain health. ISC 2020 will be held February 19-21 at the Los Angeles Convention Center in California. The 2 ½-day conference features more than 1,600 compelling scientific presentations in 21 categories that emphasize basic, clinical and translational science for health care professionals and researchers. These science and other clinical presentations will provide attendees with a better understanding of stroke and brain health to help improve prevention, treatment and outcomes for the more than 800,000 Americans who have a stroke each year. Stroke is the fifth leading cause of death and a leading cause of serious, long-term disability in the U.S. Worldwide, cerebrovascular accidents (stroke) are the second leading cause of death and the third leading cause of disability, according to the World Health Organization. Engage in the International Stroke Conference on social media via #ISC20.

About the American Stroke Association

The American Stroke Association is a relentless force for a world with fewer strokes and longer, healthier lives. We team with millions of volunteers and donors to ensure equitable health and stroke care in all communities. We work to prevent, treat and beat stroke by funding innovative research, fighting for the public’s health, and providing lifesaving resources. The Dallas-based association was created in 1998 as a division of the American Heart Association. To learn more or to get involved, call 1-888-4STROKE or visit Follow us on Facebook and Twitter.


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