New AHA Statement Stresses Need for Rapid Evaluation of Transient Ischemic Attack

A new scientific statement from the American Heart Association (AHA) stresses the need for emergency assessment of transient ischemic attack (TIA), or stroke symptoms that disappear in under an hour, to help prevent a future stroke.

The statement provides a standardized approach on how to assess patients who experience a TIA and offers guidance for health care professionals and hospitals in rural areas without access to advanced imaging or an on-site neurologist.

“Confidently diagnosing a TIA is difficult since most patients are back to normal function by the time they arrive at the emergency room,” said Hardik P. Amin, MD, Associate Professor of Neurology and Medical Stroke Director, Yale New Haven Hospital, St. Raphael Campus, and chair of the scientific statement writing committee in a statement. “There also is variability across the country in the workup that TIA patients may receive. This may be due to geographic factors, limited resources at health care centers or varying levels of comfort, and experience among medical professionals.”

A temporary blockage of blood flow to the brain, approximately 240,000 people in the US experience a TIA each year. However, the estimate may be underreported due to symptoms disappearing within an hour. Although it does not cause permanent damage, nearly one in five people with suspected TIA will have a full-blown stroke within three months, almost half of which will happen within two days.

Thus, study authors suggest it is more accurate to refer to a TIA as a “warning stroke,” rather than the more commonly used “mini-stroke.”

TIA Symptoms

TIA symptoms are the same as stroke symptoms but temporary. Symptoms can begin suddenly and share any or all the noted characteristics: symptoms begin strong than fade; symptoms typically last less than an hour; facial droop; weakness on one side of the body; numbness on one side of the body; trouble finding the right words/slurred speech; dizziness, vision loss, or trouble walking.

The statement authors cited the use of the F.A.S.T. acronym for stroke symptoms in identifying a TIA: F – face drooping or numbness; A – arm weakness; S – speech difficulty; T – time to call 9-1-1, even if the symptoms go away.

The statement additionally provided guidance on clarifying the difference between a “TIA” and a “TIA mimic.” A mimic is a condition that shares some signs with TIA but is more often caused by other medical conditions such as low blood sugar, a seizure, or a migraine. The symptoms of a TIA mimic tend to spread to other parts of the body and builds in intensity over time.

Those most at risk for a TIA were indicated to have cardiovascular risk factors, including high blood pressure, diabetes, obesity, high cholesterol, and smoking. Other risk factors included peripheral artery disease, atrial fibrillation, obstructive sleep apnea, and coronary artery diseases, as well as history of stroke.

TIA Diagnosis

After symptoms and medical history, an important first assessment for TIA is imaging of the blood vessels in the head. The statement recommends initially performing a non-contrast head CT in the emergency department to rule out intracerebral hemorrhage and TIA mimics. As nearly half of people with TIA symptoms have narrowing of the large arteries that lead to the brain, CT angiography may additionally be performed.

Data suggest about 40% of patients presenting in the emergency room (ER) with TIA will be diagnosed with a stroke based on results from a magnetic resonance imaging (MRI) scan. Blood work in the ER may help rule out other conditions that may cause TIA-like symptoms and to check for cardiovascular risk factors.

After diagnosis, a cardiac work-up is advised due to the potential for heart-related factors to cause a TIA. The statement added the preference for a work-up is to be performed in the emergency department, but a follow-up can be coordinated within a week of having TIA.

An electrocardiogram can benefit screening of atrial fibrillation, which is detected in up to 7% of people with a stroke or TIA. The AHA recommends long-term heart monitoring within six months of TIA if the initial evaluation suggests a heart rhythm-related issue as the cause of a TIA or stroke.

Early neurology consultation is additionally recommended and is associated with lower death rates after a TIA. The statement recommends following up with a neurologist within 48 hours after a TIA, but not longer than one week, given the high risk of stroke in the days after a TIA. Research cited in the statement suggests that about 43% of people who had an ischemic stroke had a TIA within the week leading up to their stroke.

Importance of Collaboration

The statement noted the critical nature of collaboration among emergency room professionals, neurologists, and primary care patients, to ensure a patient receives a comprehensive evaluation and well-communicated outpatient plan for future stroke prevention.

“Incorporating these steps for people with suspected TIA may help identify which patients would benefit from hospital admission, versus those who might be safely discharged from the emergency room with close follow-up,” Amin said. “This guidance empowers physicians at both rural and urban academic settings with information to help reduce the risk of future stroke.”