Can heart failure or low cardiac output be associated with protein deficiency and how to best recover? bnp=300 & protein 5.8g/dl

Can: Low protein due to protein loss, malnutrition, or breakdown of protein is common amongst many chronic diseases, heart failure included. Treat your heart failure aggressively, eat well, exercise.

Heart failure : Right sided hf can lead to swelling of intestines and then poor nutrient absorption. This can go along with abdominal bloating. If this is happening or if you have difficulty breathing with exercise, you need more water taken off. I like to use (lots of) Aldactone (spironolactone) for this. Also check to see if you are losing protein in your urine.