Having a "mini stroke," known as a transient-ischemic attack (TIA), appears to double the risk for a heart attack later, according to Mayo Clinic researchers.
Although TIA symptoms may last only a few minutes, they are a warning of coronary heart disease that may be unrecognised, said Dr Larry B. Goldstein, a professor of medicine and director of the Duke Stroke Center at Duke University Medical Center, who was not involved in the study.
The study confirms that "people who have had a TIA or stroke should also be evaluated for coronary heart disease," said Goldstein.
TIAs usually occur when a blood clot temporarily blocks a blood vessel to the brain. TIA symptoms are similar to stroke symptoms, but they usually resolve in minutes or a few hours and don't cause long-term disability.
"They should be treated as a medical emergency warranting immediate evaluation," said Goldstein.
Increased risk in younger people
For the study, published online in Stroke, a team led by Dr Robert D. Brown, Jr., chair of the neurology department at the Mayo Clinic, collected data on 456 patients in Minnesota, average age 72, who had suffered a TIA between 1985 and 1994. Forty-three percent were men.
Almost 66% of these patients had high blood pressure, more than 50% were smokers and 75% were taking drugs such as aspirin to prevent blood clots.
During an average 10 years of follow-up, the researchers found the risk of having a heart attack was around 1% a year, which is double the rate for people who had never had a TIA. The increased risk lingered for years and was greatest among younger people, the researchers noted.
Those under 60 years old who had had a TIA were 15 times more likely to have a heart attack, compared with people who never had a TIA.
The average time between a TIA and a heart attack was five years, Brown's team found. In addition, TIA patients who had a heart attack were three times more likely to die than those who did not have a heart attack.
Factors linked to increased heart attack risk after a TIA included being male, older age, and use of cholesterol-lowering drugs, the researchers note.
Make doc aware if you have had TIA
"Physicians and other health care providers should be mindful of the increased risk for heart attack after TIA, just as they are about the increased occurrence of stroke," said Brown.
"In fact, coronary-artery disease is an even greater cause of death after transient-ischemic attack than stroke is, surprising as that may be," Brown said.
Commenting on the study, Dr Gregg C. Fonarow, a professor of cardiology at the University of California, Los Angeles, said that "cerebral vascular disease and coronary artery disease share common risk factors and frequently co-exist".
Patients with suspected TIA require immediate medical attention, Fonarow said.
"Along with rapid assessment and evidence-based management to prevent stroke, patients with TIA should receive comprehensive measures to prevent and treat coronary artery disease," he said.
Between 250,000 and 350,000 transient ischemic attacks occur each year in the United States, Fonarow said.
According to the American Heart Association, symptoms of a TIA include:
Sudden numbness or weakness of the face, arm or leg, especially on one side of the body.
Sudden confusion, trouble speaking or understanding.
Sudden trouble seeing in one or both eyes.
Sudden trouble walking, dizziness, loss of balance or coordination.
Sudden, severe headache with no known cause.
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