Platelets trigger inflammation that leads to organ damage after heart surgery

Heart surgery can save lives, but in some cases, it can also trigger lung and kidney damage and other serious problems for reasons that weren’t clear. Now, NHLBI-sponsored research published in Science Advances has revealed that platelets—blood cells that usually help form clots—set off widespread inflammation throughout the body that leads to the organ damage.

Using a rat model, researchers found that cardiac surgery activates platelets that in turn trigger mast cells, a type of immune cell that sets off allergic reactions, such as anaphylactic shock. Further research revealed a compound called platelet activating factor (PAF) triggered the mast cells. Genetically-altered animals that lacked the ability to produce PAF or had mast cells that could not be activated by PAF did not develop inflammation. 

Treating animals with the anti-platelet medication clopidogrel helped prevent the inflammation and related problems. However, this medication, which is usually used to prevent blood clots, can be risky to use during heart surgery because it can cause life-threatening bleeding. But the finding opens the door for the development of safer medications that could help prevent this problem in people undergoing heart surgery, the researchers say.