MAYWOOD, IL – In 1993, neurologists Harold P. Adams Jr., MD, and Jose Biller, MD, and colleagues proposed a new way to classify strokes.

It became known as the TOAST classification.

Twenty-two years later, TOAST remains an effective and easy-to-use system that is routinely employed in stroke studies around the world, Drs. Adams and Biller write in an article in the journal Stroke, published online ahead of print.

Dr. Adams is a professor of neurology and director of Cerebrovascular Disease at the University of Iowa Carver College of Medicine. Dr. Biller is chair of the department of neurology of Loyola University Chicago Stritch School of Medicine.

The original article that Drs. Adams, Biller and colleagues wrote describing the TOAST classification has been cited more than 4,600 times, making it one of the most cited articles ever published in Stroke. Stroke is published by the American Heart Association/American Stroke Association, the leading medical journal on stroke care.

TOAST is used to classify ischemic strokes, which are caused by blood clots and account for about 85 percent of all strokes. A wide range of diseases can cause blood clots in the brain. Establishing the most likely cause influences both short-term and long-term prognoses. It also affects treatment decisions, especially treatments to prevent recurrent strokes.

In the late 1980s, Drs. Adams and Biller were colleagues at the University of Iowa. They needed to classify strokes for their multi-center clinical trial of a promising clot-busting drug known as Org 10172. The name of the trial, which also became the name of the stroke classification system, was TOAST (Trial of Org 10172 in Acute Stroke Treatment).

Drs. Adams and Biller aggregated groups of ischemic stroke patients into five broad categories representing the most common causes of ischemic stroke: atherosclerosis (hardening) of a large artery; blockage of a small artery; cardioembolism (blood clot that develops in the heart and travels to the brain); other demonstrated causes; and undetermined causes. These broad categories have subcategories.

The system is most useful for real-world stroke research, but it may not be as helpful when determining treatment for an individual patient, Drs. Adams and Biller write. Also, TOAST is not intended for classifying pediatric strokes, and it may not work well in emergency settings because vascular and cardiac imaging studies may not be readily available.

Despite its limitations and age, TOAST “remains a useful tool for clinicians and researchers,” Drs. Adams and Biller write. “It should not be considered as a static instrument. The system has been and can continue to be modified as advances in the diagnosis of the causes of stroke continue.”

The article is titled “Classification of Subtypes of Ischemic Stroke: History of the Trial of Org 10172 in Acute Stroke Treatment Classification.”

About Loyola Medicine

Loyola Medicine, a member of Trinity Health, is a nationally ranked academic, quaternary care system based in Chicago's western suburbs. The three-hospital system includes Loyola University Medical Center (LUMC), Gottlieb Memorial HospitalMacNeal Hospital, as well as convenient locations offering primary care, specialty care and immediate care services from nearly 2,000 physicians throughout Cook, Will and DuPage counties. LUMC is a 547-licensed-bed hospital in Maywood that includes the William G. and Mary A. Ryan Center for Heart & Vascular Medicine, the Cardinal Bernardin Cancer Center, the John L. Keeley, MD, Emergency Department, a Level 1 trauma center, Illinois's largest burn center, the Nancy W. Knowles Orthopaedic Institute, a certified comprehensive stroke centertransplant center and a children’s hospital. Having delivered compassionate care for over 50 years, Loyola also trains the next generation of caregivers through its academic affiliation with Loyola University Chicago’s Stritch School of Medicine and Marcella Niehoff School of Nursing.   

For more information, visit loyolamedicine.org. You can also follow Loyola Medicine on LinkedIn, Facebook, Instagram or X (formerly known as Twitter).

About Trinity Health

Trinity Health is one of the largest not-for-profit, faith-based health care systems in the nation. It is a family of 127,000 colleagues and more than 38,300 physicians and clinicians caring for diverse communities across 26 states. Nationally recognized for care and experience, the Trinity Health system includes 93 hospitals, 107 continuing care locations, the second largest PACE program in the country, 142 urgent care locations and many other health and well-being services. In fiscal year 2024, the Livonia, Michigan-based health system invested $1.3 billion in its communities in the form of charity care and other community benefit programs. For more information, visit us at www.trinity-health.org, or follow us on LinkedIn, Facebook, and X (formerly known as Twitter).