Topic Overview

Quitting smoking is probably the most important step you can take to decrease your chance of coronary artery disease (CAD) and a heart attack. Smoking raises your risk of getting CAD and dying early 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.

Smoking also affects those around you. Second-hand smoke increases other people's risk of coronary artery disease.

What are the benefits of quitting smoking?

Your risk for CAD drops relatively soon after you quit smoking. After your first year of not smoking, your risk of heart disease decreases by half. Also, your risk of having a heart attack decreases when you stop smoking.^{footnote 1}

When you quit smoking, you cut your risk of death even more by staying away from cigarettes for good. After 15 years of not smoking, your risk of death from heart disease is the same as if you had never smoked at all.^{footnote 1}

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. Your doctor will urge you to quit smoking so you get the most benefit from these procedures.

How do I quit smoking?

Medicines and counselling can help you quit smoking. Talk with your doctor about ways to quit for good.

For more information, see the topic Quitting Smoking.