FINDING:
Researchers at Cedars-Sinai Medical Center have found that some strokes originating from blood clots due to abnormal heart rhythm (atrial fibrillation) occurred because patients were told to stop taking a common anti-clotting drug prior to undergoing an invasive surgical procedure. The findings, presented at the 55th Annual Meeting of the American Academy of Neurology, raise questions about the application of current guidelines recommending stoppage of anti-clotting medication prior to invasive procedures and may lead to new ways to manage treatment for these patients needing surgery.
BACKGROUND:
More than 2.2 million people in the United States are estimated to have atrial fibrillation (a-fib), a condition characterized by a very fast, uncontrolled heartbeat that occurs when the upper chambers of the heart "quiver" instead of beating regularly. Because of this rapid beating, the blood is not completely emptied from the heart's chambers causing it to pool and sometimes clot. When clotted blood escapes from the heart's chambers, it can result in a stroke, especially in patients with high blood pressure, heart valve problems or heart muscle damage. In the United States, a-fib and other strokes caused by blood clots originating in the heart are responsible forabout 146,000 strokes each year.
Since patients with A-fib have such a high risk of stroke, many are treated with anti-clotting drugs that thin the blood and reduce clotting. Currently, more than 1,000,000 patients take a drug called warfarin to lower the risk of blood clots. While some younger patients with A-Fib and few risk factors for stroke can have their blood thinned with aspirin, clinical studies have convincingly shown that the majority of patients with a-fib require warfarin to prevent stroke.
METHODS:
In the study, the medical records of 178 stroke patients with a-fib were evaluated over a one-year period. Among these patients, the investigators identified 12 patients (nearly seven percent) who had a stroke after discontinuing warfarin for a medical procedure. Patients ranged in age from 54 to 91, with 77 being the average age. All had been taking warfarin for more than one year, but had temporarily discontinued taking the drug for 3-7 days prior to surgery. All strokes occurred prior to the surgery or within 1-3 days after surgery. The majority of these patients had a previous history of a-fib related strokes and nine of the 12 patients were significantly disabled as a result.
IMPLICATIONS:
These findings indicate that many a-fib related strokes could be prevented if patients avoid discontinuing use of all anti-clotting drugs for a prolonged period prior to surgery and may lead to a new approach to managing the treatment of patients at the greatest risk for stroke.
"A majority of these strokes could be prevented each year if doctors adopt a more conservative approach to discontinuing anti-clotting medication prior to a procedure in patients at high risk for stroke," said Dr. Stanley Cohen, Director of the Stroke Program in the Division of Neurology at Cedars-Sinai Medical Center.
LEAD INVESTIGATORS:
Stanley Cohen, M.D., Senior Investigator
Sergey E. Akopov, Principal Investigator