F1 visa is approved for Fall this 2015 but i want to go to a different University in spring 2016.

I have the F1 visa for a different University but due to my health issues i can’t afford to go, i have applied for spring and im sure that i will be getting quiet a few offers. If i plan not to go and apply again for a different university for the spring session, will there be any risk involved? Are there greater chances of rejections?