Coming down with pneumonia after stent removal would be very odd. Did this happen to you? I can't say I've ever heard of that happening, and would say that they are not related.
Sorry, I have no answer for you but I'm curious if by "stint" you meant "stent." I had 2 renal artery stents put in in my first angioplasty, but at a different hospital where I had my second, they were disturbed that I had stents, as they are contraindicated in cases of fibromuscular dysplasia, which basically the cause of my kidney disease. I was told by the same doctors that you can't have stents removed. Are you having stents removed?