If I quit smoking, will it significantly improve my heart health? Or is my heart condition already a done deal?

Help heart health. Any atherosclerosis caused by smoking is usually not reversible, but any blood vessel narrowing due to nicotine can be improved by stopping smoking.
Smoking and Heart Dz. This is a great quesion, because smoking and heart disease is an often under-covered topic in the media. With cigarette smoking, there is a whole host of damaging effects to the body within seconds of inhalation. Cigarette smoke alters the body's ability to regulate blood pressure control, respond to damage, and it causes cholesterol plaques to become unstable, creating a risk of heart attack.