Cigarette smoking and coronary artery disease
Quitting smoking is probably the most important step you can take to decrease your chance of coronary artery disease (CAD) and a heart attack. Although all types of tobacco smoking increase the risk of developing CAD, smoking cigarettes increases this risk more than pipe smoking or cigar smoking. Up to 30% of all deaths related to CAD are attributed to cigarette smoking.1 Smoking also increases the risk of sudden death from CAD.
Carbon monoxide, nicotine, and other substances in tobacco smoke can promote atherosclerosis and trigger symptoms of coronary artery disease. Smoking:
- Causes the platelets in your blood to clump together easily by making your blood cells more "sticky" and more likely to form clots. Clumping platelets can then block your coronary arteries and cause a heart attack.
- Can cause spasms in your coronary arteries, which can reduce the blood flow to your heart in a way similar to that of atherosclerosis.
- Can trigger irregular heartbeats (arrhythmias).
- Lowers "good" cholesterol (high-density lipoprotein, or HDL). Cholesterol-carrying lipoproteins also more easily enter the walls of your arteries, where they can develop into a hard plaque and atherosclerosis.
- Reduces the amount of oxygen that can be carried by red blood cells in the bloodstream.
People who smoke are more likely to develop angina, have a heart attack, and die from some form of heart disease.
Smoking also affects those around you. Secondhand smoke may increase other people's risk of coronary artery disease.
What are the benefits of quitting smoking?
Your risk of developing CAD drops relatively soon after you quit smoking. According to the World Health Organization, after 1 year of not smoking, the risk of coronary artery disease decreases by 50%.2 In addition, your risk of having a heart attack decreases when you stop smoking.
If you have had angioplasty or coronary artery bypass graft surgery to repair narrowed or blocked arteries, quitting smoking can decrease the risk of those arteries narrowing again. Studies show that if you continue to smoke after coronary artery bypass graft surgery or angioplasty, you may not receive the full benefit from these measures. Your risk of death is higher if you continue to smoke than if you quit.3
How do I quit smoking?
Quitting smoking is not easy. Many people have to try several times before they succeed. There are several methods for quitting smoking that have proven successful for thousands of people. Ask your doctor about nicotine replacement therapy (patches or gum that controls your nicotine craving), classes, and counseling. One of the secrets to quitting smoking is not to lose your determination to quit, even if you don't succeed right away.
For more information, see the topic Quitting Tobacco Use.
- Ockene IS, et al. (1997). Cigarette smoking, cardiovascular disease, and stroke: A statement for healthcare professionals from the American Heart Association. Circulation, 96(9): 3243–3247.
- American Heart Association (2006). Heart disease and stroke statistics—2006 update. Circulation, 113(6): e85–e151.
- Taira DA, et al. (2000). The impact of smoking on health-related quality of life following percutaneous coronary revascularization. Circulation, 102(12): 1369–1374.
Last Updated: May 29, 2008