No, there is no such score. However, in the current ACC/AHA guidelines, colonoscopy is considered a low risk procedure and low risk procedures do not require any form or invasive or non-invasive testing prior to the procedure.
No specific score as such. However in the UK we follow ESC guidelines on investigating and treating CVD prior to non-cardiac surgery - check out the ESC website for the most recent guideline (2014).
It is a very interesting question. In CRC screening, complications after colonoscopy are our main worries and it will useful to take in account guidelines