Generally, you should continue taking nicorandil and ranolazine as prescribed both before and after your angiogram to keep your heart stable. However, always confirm this with your cardiologist. Regarding your mild kidney disease, the procedure is safe. While contrast dye carries a small risk, it is very low in mild cases. Your medical team will take routine precautions to protect your kidneys, such as keeping you well-hydrated before and after the procedure and using the minimum amount of dye necessary. Just ensure they are aware of your kidney history beforehand.