Side effects after stent implanted in heart artery?

Generally none: Generally there are none if everything goes well. There can be a variety of complications however.

2 main ones: The 2 main problems with stents after placement are: 1) stent thrombosis where the stent clots off abruptly causing heart attack and risk of death, and 2) renarrowing of the stent. Renarrowing occurs in 5% of medicated stents and approximately 20% of unmedicated stents.