What is the best antiplatelet treatment after a stroke?

This review compared using two antiplatelet medications to aspirin (Bayer) alone following a stroke. It found that dual antiplatelet therapy (DAPT) reduced the risk of a second stroke, but led to more bleeding.

Stroke is a leading health challenge in developed countries. A stroke occurs when an area of the brain is deprived of blood and oxygen. Strokes can cause brain damage leading to loss of speech or movement and can be fatal. One type of stroke is an ischemic stroke, in which blood flow is slowed or blocked. A common cause of an ischemic stroke is a blood clot forming in the brain, or breaking off from an alternate location and traveling to the brain. Antiplatelet therapy is typically used after strokes potentially related to blood clots. These medications affect platelets, which are small components in the blood which facilitate blood clotting and wound healing.

At low doses, aspirin prevents platelets from releasing chemical signals which start the blood clotting process. At higher doses, aspirin also reduces inflammation and pain. While daily aspirin can be used alone to treat strokes, dual antiplatelet therapy (DAPT) combines aspirin with a second medication. This second medication can be clopidogrel (Plavix) or ticagrelor (Brilinta). These second medications block a protein that helps activate platelets, which is known as P2Y₁₂. Thus, DAPT uses two medications that work in different ways to prevent clotting.

Antiplatelet therapy is used following a stroke to prevent further blood clots. However, both aspirin alone and DAPT increase the risk of bleeding after an injury. It is not clear whether DAPT leads to better outcomes following a stroke than aspirin alone.

This review included 3 trials of 21,067 patients following a loss of blood flow to the brain. This was either an ischemic stroke or a briefer loss of blood flow known as a transient ischemic attack (TIA). Half of the patients received DAPT, and the other half received aspirin alone. Treatment was started within 12 to 24 hours of the stroke or TIA. The patients were followed for either 30 or 90 days, depending on the study.

Patients using DAPT had a 27% lower risk of a second stroke, which was significant. However, the risk of severe bleeding was significantly higher when using DAPT, with 2.48 times as many episodes of severe bleeding. There was a trend toward more deaths for patients using DAPT.

This review found that following a stroke or TIA, DAPT reduced the risk of a second stroke more than aspirin alone. However, DAPT also increased the risk of severe bleeding.

The authors suggest that most of the additional benefit from DAPT in preventing additional strokes was in the first 30 days, while the risk of bleeding continued for the entire 90 days studied.

Talk to your doctor about which kind of antiplatelet therapy, and for how long, is best given your history of stroke and risk of bleeding.