Physician-owned cath labs exist in the US but are rare, and as reimbursements for cath and PCI have decreased it has become increasingly impractical from a financial standpoint.
It is not correct that a cath lab HAS to have CT surgery backup, not anymore. There are plenty of small community hospitals running cath labs without on-site surgery backup. Whether or not they should be doing so is controversial, but it is becoming a fairly widespread practice.