So you want something like Zelda?
The kind with just 3 hearts and you remove one for every hit?
I'd suggest you use a Tiled Background Sprite with one heart sprite within it, stretch it to 3 hearts.
When you get hit, set the event to set it's width to itself with .ImageWidth and minus off eg. 20px from it?
So Life.ImageWidth - X (X being the width of each Heart sprite)
If you want to regain one, simply add it back.
Also, you should set a limit by checking if imageWidth is already maxed or 0.
Hope this helps!