Heart Disease

About Heart Disease

Heart disease, also called coronary artery disease, is the narrowing or closure of arteries that supply blood to the heart.

The narrowing is caused by deposits of cholesterol and calcium that slowly build up along the artery wall. These deposits restrict blood flow. They can also break away from the artery wall and cause a blockage that prevents blood from reaching the heart muscle. This may result in a myocardial infarction, commonly known as a heart attack.

Heart disease is the leading cause of death among American men and women. Over 64 million Americans live with cardiovascular disease, which includes heart disease and also causes stroke. Cardiovascular disease is also the leading cause of permanent disability in the workforce.

The first signs of heart disease are most often heart attack or sudden death. This makes it challenging for doctors and patients to proactively diagnose and prevent it. Fortunately, there are tests that enable heart disease to be detected early, before it causes a heart attack and/or disability.

Facts About Heart Disease

There are widely available non-invasive stress tests, as well as invasive angiography, that show if there is a significant blockage in a coronary artery. However, the blockages leading to heart attacks are most often in vessels that are not particularly narrowed. More commonly, small plaques — the kinds that frequently are not seen by these tests — rupture and obstruct blood flow.

For many years, doctors thought that heart attacks were caused by the gradual narrowing of the coronary arteries because of atherosclerosis. This gradual narrowing would eventually prevent enough blood from reaching the heart muscle and cause a heart attack. Recently, however, researchers noticed that blockages leading to heart attacks were most often in fairly clear vessels. In fact, they found it impossible to predict which blood vessel will become blocked, even when they knew which vessels had been narrowed by atherosclerosis.

At the same time, researchers also discovered that atherosclerosis behaves like an inflammatory process. Cells of the immune system can interact with the fatty deposits in the artery walls and cause inflammation. Plaques with more inflammation tend to be less stable and prone to rupture. When the plaque ruptures, a blood clot forms and the involved blood vessel may become blocked. This explains why smaller plaques, which may not be visible by invasive angiography, are often the cause of fatal heart attacks. These inflamed plaques are referred to as vulnerable plaques.

Plaques with less inflammation tend to calcify and are less likely to rupture and cause a heart attack.

Here are some additional facts about heart disease:

• The American Heart Association cites that every year about 785,000 Americans have their first heart attack. Another 470,000 Americans who have already had a heart attack have another.
• On average, every 40 seconds, someone in the United States dies from heart disease.
• According to the American Heart Association, more than 2,400 Americans die of cardiovascular disease each day. That’s an average of one death every 37 seconds.
• Based on the Framington heart study, 5% of heart attacks occur in people under the age of 40 and 45% of heart attacks occur in people under the age of 65.
• The Centers for Disease Control and Prevention indicates that the age-adjusted mortality rates for coronary heart disease have declined steadily in the United States since the 1960’s. This is likely due to better control of risk factors and better treatments.
• About 50% of deaths occur within one hour of the heart attack –outside a hospital.
• According to a 2010 American Heart Association report, more women than men die from heart disease each year. Women are less likely than men to receive appropriate treatment after a heart attack.

Risk Factors and Symptoms

Risk Factors for Heart Disease

There are factors that can make a person more vulnerable to heart disease. Heart disease often shows no symptoms until a serious problem arises, so it’s important that you are aware of your level of risk. If you have two or more of the following factors, you have an increased risk of heart disease.

• Age 45 or older (men)
• Age 55 or older (women)
• Family history of premature heart disease
• High LDL (“bad”) cholesterol level and low HDL (“good”) cholesterol
• Current cigarette smoking
• High blood pressure, or currently taking blood pressure medication
• High stress lifestyle
• Lack of regular exercise
• Diabetes
• Overweight by 20 lbs. or more

Risk Categories

The above factors are used to place patients in high, moderate or low-risk categories. A high-risk person has a history of heart attack or known coronary artery disease. A person with high risk has two or more of the risk factors mentioned above and has greater than 2% per year risk of having a major coronary event (heart attack or sudden cardiac death). People at low risk are those with less than a 1% chance per year of a coronary event.

There is a significant degree of uncertainty when using risk factors alone to determine a risk category. For example, 50% of those suffering their first heart attack have normal cholesterol levels. Relying only on lifestyle and risk factors cannot adequately diagnose or predict heart disease.

Newer Risk Measurements

Recently, measurements of low-density lipo-protein (LDL), or ‘bad’ cholesterol, and C-reactive protein (CRP) have been added to help determine a person’s risk of heart attack. People with both high LDL and high CRP have more than five times the risk for a heart attack than those with the lowest LDL and CRP. Research is also looking into subcategories of LDL, particularly the size of the molecules, to help further classify patients and to identify who’s at risk.

However, none of these markers can tell if you definitely have heart disease. Coronary CTA is the only non-invasive means to exclude heart disease before it limits blood flow to the heart muscle.

Reducing the Risk

Heart disease is not an inevitable part of aging. In the case of heart disease, knowledge is power. By assessing your risk for heart disease, you can take the appropriate actions now to prevent heart disease in the future.

Imaging exams can help you and your doctor more accurately determine your risk. Talk to your primary care provider about ways you can determine and reduce your risk level.

Following are some of the ways you can reduce your risk of heart disease:

• Know your family history of heart disease and share it with your primary care provider
• Maintain a healthy body weight
• Get enough exercise
• Eat a healthy diet to prevent or reduce high blood pressure and high cholesterol
• Stop smoking
• Reduce your level of stress
• Follow your healthcare provider’s instructions for controlling diabetes
• Follow your healthcare provider’s instructions for stroke prevention

Diagnosis and Treatment

Diagnosing Heart Disease

Your risk for heart disease can be evaluated through imaging exams using computed tomography (CT scans).

Coronary Artery Calcium Scoring, also known as a Heartscreen CT, is a non-invasive CT scan to analyze the presence and amount of calcium in the coronary arteries. The higher the level of calcium that has been deposited in the arteries, the higher the risk of a heart attack.

Calcium scoring adds predictive value to the already known risk factors. For example, in a recent study, patients in the low-risk category who also had a low calcium score had almost no risk for a heart attack. It was those patients with no risk factors, but a high calcium score, who had a 1% risk of heart attack.

Patients with the highest calcium scores have been found to have up to a 14% annual risk of heart attack.

CT angiography (CTA) is a powerful tool that enables doctors to image the whole heart for the first time. Using this non-invasive CT scan, a radiologist can see both the lumen (the hole in the middle of the tube where the blood flows) and the vessel wall. This scan can show very small amounts of plaque building up in the walls of the coronary arteries, often before they can be seen by other non-invasive imaging or catheter angiography.

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