Have CAD. #2 tooth needs root canal. No visible infection. Pulpitis. Does delay have systemic effects ie speed up atherosclerosis, increase MI risk?

Risk. If root canal treatment is required it usually means that the nerve of the tooth is infected. "...itis" means inflammation, again with infection usually the cause. Any infection is a danger to other organ systems. Important that you have treatment ASAP. Infection can spread readily and do damage. If you have not as yet consulted with a root canal specialist, an Endodontist, please do so.