Heart Blockage, Stents Placed, Numbness, Weight Loss. What Is This A Sign Of?

My Grandfather is eighty years old. About three months ago, the doctor found two blockages and put one stent in, and then two weeks later they put the second one in. During the second one, the first one collapsed and he had to have it fixed at the same time, which meant that they had to put an excessive amount of the dye in. Well since then, my grandpa who has been a rock mason for the last seventy years of this life and worked everyday up until the day he had the stents put in, has lost all energy, he can barely make it to the couch and back to his bed. He has lost over twenty pounds, and has had numbness in his body. It started in his hand and feet . Now, tonight, his hands and feet are completely numb and numbness has also developed in his left knee and right side of chest . His heart doctor knows and keeps saying that it is unrelated and that his heart is fine. But none of this started until the second stent surgery. Please tell me what you think about this. What is this a sign of? And should he go to an ER? Please help