To my ears, somehow 'blood-rich oxygen' sounds very peculiar. I would write, or say, 'oxygen-rich blood' because oxygen is dissolved in blood. Does this 'blood-rich oxygen' sound fine to you? I visualize oxygen with vaporized blood flying around in it.
Your heart pumps blood-rich oxygen to your body's tissues - but the heart muscle needs oxygen itself. The coronary arteries are small vessels lining your heart's surface that do this job perfectly, in exact synchronization with the beats of the heart. ('How does angioplasty work?' in 'How it works' published by Imagine Publishing)