DMR? = Bypass grafts?
Open heart surgery is hell on the body. Anyone's body. Perhaps the heart needs some recovery time, so they put the balloon pump in to help it rest. Inotropes like Dobutamine may have been added as well as the vasopressors. A week on those supports is not unheard of, and will be weaned off as tolerated. Usually they try to wean the balloon pump first, get that out, then work on the drips. Some surgeons will hold off on extubation until the balloon pump is out. CVVH may be started instead of hemodialysis until vitals are more stable. While that's all very scary, it's also very common, unfortunately.
Thorough physical assessments are par for the course to make sure side effects are minimized.