Hello, The optimal way for checking if the stent is working is the stress test. I would recommend either the echo stress test or nuclear stress test in an experienced center. These two test have quite high accuracy in detecting the problems with vessels and stents. The other method is to repeat coronary angiography, but I wouldn t recommend it at this point, as it is an invasive procedure, and if we can gain as much information with a none invasive scan, the later is preferred. And in patients with previous stents we perform coronary angiography when there is a very high suspicion of stent blockage, which is not your case. Wishing you a good health. In case of any further questions don t hesitate to contact me. Regards, Dr. Baghdasaryan