© Hongqi Zhang (aka Michael Zhang) | Dreamstime
Coronary artery disease (CAD) is the most common form of cardiovascular disease in the U.S., and claims the lives of almost 400,000 Americans each year. CAD develops when the arteries that supply blood to the heart become narrowed or blocked by a buildup of plaque: a waxy deposit made up of cholesterol, other fatty substances, calcium, and cell waste. Narrowed arteries reduce the flow of oxygen-rich blood to the heart, which can result in angina (chest pain), while heart blockage symptoms can result in a heart attack.
How CAD Happens
CAD is believed to originate from damage to the endothelium, a layer of specialized cells that lines the intima (the inner layer of an artery, which comes into direct contact with blood as it circulates). “Damaged areas make it easier for plaque to find a foothold in the endothelium, and then gradually accumulate,” says Mount Sinai cardiologist Bruce Darrow, MD, PhD. “The body responds by sending white blood cells to the plaque in an attempt to remove it and heal the damaged area.” Platelets (clotting agents present in the bloodstream) also begin to accumulate around the plaque, particularly if it cracks. “This may cause a blood clot to form, raising the risk for a heart attack,” says Dr. Darrow.
Possible causes of the artery damage that can jumpstart CAD include high blood pressure, high cholesterol and diabetes, along with smoking, obesity, and lack of physical activity. “Having a family history of CAD also makes you more vulnerable,” Dr. Darrow adds, “and older adults are at greater risk for CAD because their age makes them more likely to have damaged arteries.”
WHAT YOU CAN DO
- Heart-healthy eating is vital—prioritize fruits and vegetables; low-fat dairy; whole grains; healthy fats (for example, olive oil, walnuts, avocado, sunflower seeds); legumes, such as lentils, peas and beans; fatty fish, such as salmon, trout, and mackerel; and poultry. Cut back on red meat, trans-fat (found in baked goods), refined (white) grains, and sodium.
- Maintain a healthy weight Older adults are regarded as overweight if their body mass index (a relation of weight to height) is 27 or greater.
- Get plenty of exercise, since it can help lower cholesterol levels and aid in weight loss.
- Quit smoking It damages the lining of your arteries.
- Manage stress Stress can contribute to heart risk factors such as high blood pressure, and may trigger angina in people with CAD.
Medications to Treat CAD & Prevent Heart Blockage Symptoms
In early CAD, lifestyle measures that reduce your risk factors (see What You Can Do), along with medications such as statins and drugs that lower high blood pressure can be sufficient treatment options.
- Statins lower cholesterol levels, thereby reducing the risk for plaque build-up in the arteries. “These drugs have been shown to reduce the need for revascularization in people with CAD, particularly if they are combined with a healthful diet and increased physical activity,” Dr. Darrow notes. However, statins are associated with side effects, notably muscular aches and pains. “If muscle pain occurs, trying a different statin is advisable,” Dr. Darrow says. “Studies suggest that about three-quarters of people who switch to a different statin are able to tolerate the new drug.” More serious side effects are rare, but it is possible for statins to damage the liver—there also is evidence that the drugs may increase the risk for diabetes, particularly in elderly women.
- Non-statin options If statin side effects continue to be an issue even after trying a different drug, newer non-statin alternatives may be tried. While statins work by inhibiting the production of cholesterol in the liver, cholesterol absorption inhibitors such as ezetimibe (Zetia®) decrease the amount of cholesterol the body absorbs from food—however, ezetimibe is not as effective as statins when used alone. “Drugs called PCSK9 inhibitors are another option,” says Dr. Darrow. “Taken once every two to four weeks, they lower cholesterol by suppressing a protein that determines how much cholesterol the liver eliminates from the body.” Two PCSK9 inhibitors—alirocumab (Praluent®) and evolocumab (Repatha®)—have been approved by the Food and Drug Administration, and both are administered via injection.
- High blood pressure drugs CAD patients also will likely be prescribed blood pressure-lowering drugs that can help reduce their risk for heart attack. Angiotensin-converting enzyme (ACE) inhibitors and diuretics are the most commonly prescribed options.
- Nitroglycerin can help ease angina: chest pain that occurs when the flow of blood to an area of the heart is decreased.
For most people with CAD, lifestyle modifications and medications are sufficient when it comes to managing the condition. But if your coronary arteries are severely blocked, your doctor may recommend revascularization to re-establish the blood supply to your heart. Two approaches are available—percutaneous coronary intervention (PCI, which is also known as angioplasty), and coronary artery bypass surgery (CABG).
- PCI is carried out using “keyhole” surgery. A catheter is inserted into an artery through a small incision in the arm or groin. At the tip of the catheter is an inflatable balloon surrounded by a collapsed stent, which is essentially a tiny mesh scaffold. “The catheter is threaded through the artery to the blockage in your heart, and the balloon is expanded to compress plaque, thus clearing the blockage,” Dr. Darrow explains. “As the balloon expands, it opens the stent, which remains in place to keep the artery open when the balloon is deflated and the catheter is removed.”
- CABG In CABG, blood vessel grafts taken from veins in the patient’s legs or the internal thoracic arteries in their chest wall (or parts of both) are used to bypass blockages in the coronary arteries. CABG is major open surgery carried out through an incision in the middle of the chest—the procedure takes four or five hours, and usually involves being connected to a heart-lung machine so that the heart can be stopped while the grafts are placed. You’ll spend the night in the intensive care unit after the surgery, and about five days in the hospital.
“Which revascularization approach is best for you depends partly on the location of the blockage in your coronary arteries,” Dr. Darrow observes. “For example, if you have multiple diseased blood vessels, then CABG may be a better option than PCI.” He adds that your health status also matters. “Older adults are at increased risk for complications such as major bleeding and stroke both during and after revascularization procedures, and CABG is particularly risky due to the fact it is open surgery,” he explains. “Other possible complications with CABG include infection, kidney failure, and heart attack—so older, sicker patients may be advised to have the less-invasive PCI.” However, research suggests there may be a long-term survival advantage for CABG over PCI, and CABG patients also need repeat revascularization less frequently than patients who have PCI (although recurrent narrowing or blockage only occurs in about 10 percent of PCI patients). “Another thing to keep in mind is the blood-thinning medications you will need to take after PCI,” Dr. Darrow adds. “If you have bleeding problems that mean you can’t take these drugs, you may not be a good candidate for PCI.”