MONDAY, Nov. 12, 2007 (HealthDay News) -- Patients who've suffered a minor stroke -- called a transient ischemic attack, or TIA -- have a substantial risk of suffering a major stroke within seven days.
But that risk of a second, bigger stroke is lowest among TIA patients treated as emergency cases in specialist stroke units, says a new British review of previous studies that included a total of 10,126 patients.
The researchers concluded that there's a 5.2 percent risk of a major stroke within seven days of a TIA, meaning that about 1 in 20 TIA patients will have a major stroke within a week. But the risk among TIA patients who received emergency care in specialist stroke units ranged from 0 percent to 9 percent, while the highest risk -- 11 percent -- was for patients who didn't receive emergency care.
The findings were published online Nov. 11 in The Lancet Neurology, and will appear in the December print issue of the journal.
"The risk of stroke reported amongst patients treated urgently in specialist units was substantially lower than risks reported among other patients treated in alternative settings. These results support the argument that a TIA is a medical emergency and that urgent treatment in specialist units may reduce the risk of subsequent stroke," said the study authors, from Oxford University's Stroke Prevention Research Unit.
Studies of major stroke risk after TIA have produced conflicting findings, with seven-day stroke risk ranging from 0 percent to 12.8 percent. The inconsistent findings among the previous studies that were included in the new review could be explained by differences in study method, setting and treatment, the review authors said.
"Our study almost fully explains why the results of previous studies have been conflicting and illustrates the importance of methods used by a medical study when interpreting its results," they concluded.
The researchers said reliable estimates of major stroke risk following a TIA could maximize the benefits of early treatment, allow effective planning of service for patients, assist in the design of clinical trials, and justify investment in public education.
Another expert, Dr. Keith Siller, medical director of New York University Medical Center's Comprehensive Stroke Care Center, called the study important for several reasons.
"The significant recurrence rate of a second more serious stroke within only one week's time shows that a patient with a minor stroke or TIA is not 'out of the woods' just yet and still remains at risk for an even worse stroke that mandates urgent hospitalization to expedite their evaluation even though they may appear to be back to normal," Siller said. "This is analogous to a patient with chest pain who may be having angina as a warning for impending heart attack and is admitted for additional testing to avoid sending them home and having them suffer a fatal heart attack outside the hospital."
Siller, who's also an assistant professor at the NYU School of Medicine, added that the study also emphasizes that "patients with TIA or minor stroke should be treated in stroke centers with specialized units since the care provided is specifically targeted for stroke and does result in better outcomes compared to a general medical ward."
What's more, Siller said, "these results need to be understood by insurance companies and HMOs that have unofficially discouraged doctors from admitting these same patients and prefer them to be worked up electively as outpatients. The reality is that completing all of the necessary testing as an outpatient within one week is often not possible, during which time the patient may have the second more devastating stroke that might have been prevented had they been in the hospital setting."
The American Heart Association has more about TIA.