One major thing to note while heart stent placement is to check whether the stent helps dissolve the blockage and gets set with the blood vessel. This is the job of a cardiology doctor.
To ensure this there are recent advanced techniques called IVUS and OCD. Using these techniques, the cardiologist can surely know whether the heart stent fits the blood vessel properly.
If the stent is placed and fit properly, the chance of the clot happening again is very low.