You are correct in your observations. Having a spouse with several health problems who takes meds faithfully but resists diet and other easy keep well ideas, can understand your concerns. Husband needs to take ownership of HIS health, spousal nagging doesn't work.
Accompanying spouse on next appointment might be helpful----you can tell people things but until they actual HEAR and accept advice, little you can do to change their ways. Indvidual medical advice not provided at this website.
Great info here:
MedlinePlus Medical Encyclopedia: Heart Failure
The U.S. National Library of Medicine and the National Institutes of Health maintain this site. Here you'll find diagrams of the heart, definitions, and links to more information on causes, risk factors, symptoms, tests, complications, and treatment.
Best Wishes to both of you.