daah,
I hope your Dad is well. I don't know where you live, but the Cleveland Clinic Foundation (CCF) is rated highest in the United States for cardiovascular care. Furthermore, the CCF has very good systems in place for facilitating timely visitation by international patients.
Typically, people can be seen on one day and have angiography the next -- if necessary. The risk of a major adverse event is approximately 1 per 1500 cases at CCF.
To find an interventional cardiologist, go to the CCF website: http://www.clevelandclinic.org/. The phone number is 1-800-CCF-CARE. Any of the interventional cardiologists are first rate.
Good luck.