A British research team at St. George's Hospital Medical School in London, have found that the addition of the anti-clotting drug Plavix to daily doses of aspirin helps prevent the risk of later strokes better than using aspirin alone.
In previous trials the drug was proven able to help prevent second heart attacks, strokes and death among patients who had suffered heart attacks.
This new study "Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic Carotid Stenosis" or CARESS, shows the Plavix/aspirin combination can also reduce the number of tiny blood clots that can predict the risk of stroke, including so-called mini-strokes, in stroke patients.
Dr. Hugh Markus, the study leader, says that the combination of clopidogrel and aspirin was seen to be significantly more effective at reducing blood clots than aspirin alone.
The team studied 107 stroke patients at 11 medical centers in France, Germany, Switzerland and Britain all of whom had at least 50 percent narrowing of the carotid artery, the main vessel carrying blood to the brain and each had suffered a stroke or a transient ischemic attack, (a mini-stroke ), within the last three months. Half the patients were given aspirin plus Plavix, generically known as clopidogrel, and half were given aspirin alone for a week.
The team then looked for little blood clots called microemboli in the brain by using transcranial Doppler ultrasound.
Microemboli were detected in 43.8 percent of the patients who got both drugs compared to 72.7 percent of the group treated with aspirin only.
Stroke patients are at risk of another stroke, especially within the first week, and Markus says the risk is particularly high in patients with narrowed carotid arteries, suggesting that more aggressive anti-clotting therapy may be indicated for patients in this group. He also says that the results 'demonstrate the power of the technique to detect treatment effects in relatively small groups of patients, far less than those required with the use of clinical end points such as stroke, and suggest this technique may help screen different drug combinations for further testing in large and expensive clinical trials'.
The study by Markus and colleagues is published in the journal Circulation, published by the American Heart Association.
Plavix is sold by Sanofi-Aventis and Bristol-Myers Squibb Co.