Can I take 81 mg baby aspirin just 3 times a week and still get the heart benefit. What is the aspirin half life.?

Reduce bleeding. When a patient on therapeutic Aspirin experiences excessive bleeding associated with minor trauma, we commonly reduce the dosing to every other day as a compromise, thereby shifting the risk/benefit ratio back to an acceptable level.
3-7 hours. The half life of Aspirin is short (3-7 hrs).The 81mg preparation used for it's antiplatelet properties(heart benefit) is already reduced considerably from the standard 325 & 500mg tabs used for pain and inflammation. Using it every other day may provide some benefit, but the studies reflecting it's benefit were done with daily use. A change in the pattern is likely to effect the level of benefit.