The most popular and important item on high elo is Cauterize. Maybe the second top is Rejuvenate. All of them are about the heals: increase our healer's and decrease the enemy's. I think these items needs nerf, becuse these are too important.
The ally heals are realy strong as well, this is why these items are so popular. So I suggest a buff for heal decreaseing with a nerf for Cauterize:

-Weapon shots decrease enemies heals by 30% for 1.5s by default.
-Cauterize decreases the enemies heals by 20% more per level. (the max level still garants 90%)
-Increase the cost of Rejuvenate from 200 to 250.

I think these simple changes could balance the items without make the heals OP.