Medication for the long-term treatment of coronary artery disease

Photo of a woman taking a tablet (Elena Elisseeva / iStock / Thinkstock)

The long-term treatment of coronary artery disease (CAD) mainly involves taking medication. Various medications can relieve the symptoms and lower the risk of complications.

In order to prevent the development of related medical conditions, all people who have coronary artery disease (CAD) are advised to take two types of medication: Antiplatelets to prevent blood clots, and statins to protect the blood vessels.

Beta blockers are sometimes taken too, to reduce the heart's workload, particularly in people who have heart failure or high blood pressure.

Good-quality studies have proven that these medications can lower the risk of complications such as heart attacks or strokes. People who have certain other medical conditions too may take other medications such as ACE inhibitors. But even the very best treatment with medications will offer only limited protection from heart disease.

All medications can have side effects. Yet it is often possible to avoid them by adjusting the dose or by choosing a different medication in the same group of drugs. The side effects often go away after a while too, once the body has got used to the medication.

The risk of side effects may increase when two or more medications are taken together, because they may interact. It is therefore important to tell your doctor what medication you are already taking.

Generally speaking, the more risk factors someone has, the more likely it is that he or she will benefit from medication. The important thing is to continue to take your medication and to take it regularly – its protective effect lasts only as long as it is taken.

Antiplatelets

Blood platelets, also known as thrombocytes, help blood coagulate (clot). This is important to seal wounds and stop bleeding, for example. But they are also involved in the formation of blood clots (thrombus), which may end up blocking blood vessels. Antiplatelets inhibit this function of the platelets in the blood. They slow down the blood-clotting process and help prevent the platelets from sticking to blood vessel walls. Antiplatelets are also referred to as antiaggregants.

Two antiplatelet drugs have been approved for the long-term treatment of CAD in Germany and other countries: Acetylsalicylic acid (ASA) and clopidogrel.

  • ASA is the drug found in painkillers like Aspirin. Low-dose ASA has been used in the prevention of heart disease for many decades. People with CAD typically take one 100 mg tablet per day. Higher doses increase the risk of side effects but don't provide better protection from complications.
  • Clopidogrel is mostly used by people who don't tolerate ASA well or can't take it for other reasons. One 75 mg tablet of clopidogrel is taken per day.

Research on ASA and clopidogrel

ASA is a well-studied drug: Taking it regularly can prevent complications like heart attacks or strokes in people with CAD, and increase their life expectancy.

Expressed in numbers, studies that lasted five years came to the following conclusion

ASA prevents heart attacks or strokes in about 5 to 10 out 100 people who have CAD.  Just how much someone benefits from this medication will very much depend on their personal risk factors.

A large study compared ASA and clopidogrel directly. Both medications were found to be equally good at preventing complications.

Side effects

Antiplatelets reduce blood clotting. This means that people start bleeding more easily and it can take longer for bleeding to stop. So they are more likely to get bruises, for instance. Bruising and other minor bleeding events like nosebleeds are no cause for alarm, though. Dark red or black stool and vomit with blood in it, on the other hand, may be signs of bleeding in the stomach and need medical attention.

If 100 people with CAD take ASA over a period of five years, it leads to bleeding that requires treatment in about 2 to 3 of them. But most of these cases can be easily treated and do not have any long-term effects. Someone who has had stronger bleeding will often be prescribed a medication called a proton-pump inhibitor in addition to ASA. This drug protects the mucous lining of the stomach and helps to prevent stomach ulcers.

One very rare, but serious, side effect of antiplatelets is bleeding in the brain. A very strong and sudden headache is a sign of such bleeding, especially if it occurs together with other problems like impaired vision, dizziness, paralysis or numbness. If these kinds of symptoms occur, it is important to call an emergency number right away (112 in Germany and other countries, 911 in the U.S.).

The probability of dying from bleeding in the brain due to antiplatelets is low, though: Over a time period of five years, this happens in less than 1 out of 1,000 people.

Statins

Statins are medications that lower certain cholesterol levels in the blood (cholesterol-lowering drugs). The beneficial effects of statins aren't only due to their cholesterol-lowering effect, though. It is currently thought that they also protect the blood vessel walls, for instance by inhibiting inflammations. So they are given to everyone who has CAD – regardless of whether their cholesterol levels are too high.

The following statins have been licensed for use in Germany: atorvastatin, fluvastatin, lovastatin, pravastatin and simvastatin. So if someone doesn't tolerate a certain statin, they can switch to a different one. Simvastatin and atorvastatin are by far the most commonly used statins. Various doses are used. Simvastatin is often taken at a dose of 40 mg per day, and atorvastatin is often taken at a dose of 10 mg per day.

Research on statins

Statins have also been well-studied. They can lower the risk of CAD complications and increase life expectancy. Research on the use of statins for people known to have CAD has found the following:

If people with CAD take statins over a period of five years, medical conditions like heart attacks, strokes and other forms of blood vessel blockages are prevented in about 5 out of 100 of them. The positive effect may be bigger or smaller, depending on the person's individual risk factors.

Side effects

Statins are generally well tolerated. However, a few studies suggest that there is a small group of people who react more sensitively to these drugs, and who may get muscle pain when they use them.

Statins can increase people's blood sugar levels, making them more likely to get type 2 diabetes. But the risk of this happening is low: In studies, an additional 3 out of 1,000 people who used statins over several years were newly diagnosed with diabetes.

Rhabdomyolysis is an extremely rare but serious side effect where the muscle tissue in certain muscles gradually breaks down. This causes paralysis, and the breakdown products that are released from the muscles can severely damage the kidneys. In studies, this side effect occurred in 1 out of 10,000 people who had long-term treatment with statins. Signs of rhabdomyolysis include muscle pain and dark-colored urine. It is important to seek medical advice if you have these symptoms.

Beta blockers

Beta blockers lower your heart rate, which reduces the strain on your heart. They also reduce blood pressure. They are particularly suitable for people who have CAD as well as high blood pressure or heart failure. Taking beta blockers can increase their life expectancy. These medications have the advantage of relieving angina (chest pain) too. People who have both CAD and angina are routinely given beta blockers as well as antiplatelets and statins.

There are a number of different beta blockers. The most commonly used ones are bisoprolol and metoprolol. Because they work in slightly different ways, they are taken at different doses: The usual dose for bisoprolol is 2.5 to 5 mg per day, and the usual dose for metoprolol is 50 to 100 mg per day.

In people who already have heart failure, it's important to start treatment at a low dose and then gradually increase the dose. When people stop taking beta blockers, the dose is also reduced gradually because it might otherwise lead to a sudden increase in blood pressure and heart rate.

Side effects

If beta blockers lower people's heart rate or blood pressure too much, they may feel weak and exhausted. But this can often be avoided by adjusting the dose of the medication. Other possible side effects of beta blockers include reduced sexual desire and erection problems. But fewer than 1 out of 100 people have these problems as a result of taking this medication. Beta blockers are usually well-tolerated.

ACE inhibitors and angiotensin II antagonists

ACE inhibitors and angiotensin II antagonists (also known as sartans) are blood-pressure-lowering drugs. One thing they do is cause the blood vessels to widen and blood pressure to drop. This lowers the pressure on the heart’s chambers.

ACE inhibitors and angiotensin II antagonists are not part of standard treatment for coronary artery disease in Germany. For people with CAD who already have heart failure, though, these drugs can lower the risk of complications and improve life expectancy. Because of this, people who fall into this category sometimes use these medications in addition to a beta blocker. ACE inhibitors are typically used first because they are better established. But if someone doesn't tolerate them well, angiotensin II inhibitors are considered.

Side effects

ACE inhibitors and angiotensin II antagonists can cause side effects if they lower blood pressure too much. Signs that this has happened include tiredness and dizziness. In order to avoid these kinds of side effects, people are usually given a low dose to start off with, and the dose is then increased as needed. ACE inhibitors may also cause a dry cough. This side effect is less common with angiotensin II antagonists.

Treatment options for angina (chest pain)

There are other drugs besides beta blockers that can be used to relieve or prevent angina symptoms. The main ones are calcium channel blockers and nitrates.

Calcium channel blockers widen your blood vessels, and some also slow your heart rate. This lowers your blood pressure as well as the pressure in your heart’s chambers. Calcium channel blockers are mostly used by people who can't tolerate or take beta blockers, or who aren't getting enough relief from beta blockers. Calcium channel blockers can have a number of different side effects such as drowsiness, hot flashes, constipation and water retention in the legs.

Nitrates widen blood vessels too. These medications work quickly and can be used – as a spray, for instance – to treat acute attacks of angina. People who have CAD with angina often carry nitrate medication with them to be taken as needed. Nitrates can make you feel tired and sluggish.

Managing medication use over the long term

People who have CAD usually take several different medications over a long period of time. It can be hard to keep track of everything. Various things can help make it easier to take the medication, though. The following have proven especially useful:

  • Keeping your medicine schedule as simple as possible.
  • Using medicine dispensers with small compartments for each day, making it easy to see whether a tablet has been forgotten.
  • Seeing your doctor regularly so that questions about the treatment can be addressed.

Many people are afraid of taking medication regularly for a long period of time, for instance because they might worry about the build-up of medication in their body over time. But these worries are unfounded. Our bodies continuously break down medications and get rid of them with the help of various mechanisms. All of the medications described here have also been carefully tested in studies.

But it's still a good idea to talk with your doctor about all of the medications you are taking. This can help to avoid taking medications that you don't need (any more). It can also lower the risk of the different medications altering each other's effects.