My father is 77 and has been reffered to a surgeon for Carotid Artery Surgery. He had a quadruple bypass in 1994 and another in 2000. He has a pacemaker/defibrilator since 2006. He went in for a carotid stent in 2004 and would up having pulminary edema and needing a stent in his heart instead. He has an EF of 25%. Is he too high risk to undergo this type of procedure?