Exhaustion would be a key answer to this but they're others if needed.
A patient with coronary artery disease (CAD) necessitates to have a coronary artery bypass graft (CABG) if there’s too much plaque insider a patient’s coronary arteries. This is the case if the coronary heart disease is severe wherein too much plaque inside arteries prevents blood flow which can lead to heart attack. During CABG, a healthy artery is connected to a blocked artery to create a new pathway for blood to flow to the heart.
I think, 2. True 3. False 4. False.