Daily aspirin therapy for the heart: A user’s guide

by Tyrone M. Reyes, M.D.

Aspirin has long been known to relieve fevers, aches, and pains. But in recent years, it has also gained a reputation as a drug that can lower the risk of heart attack and clot-related stroke. As a result, millions of people around the world (50 million in the United States alone!) now take a daily dose of aspirin. So, if you’ve had heart problems or doctors have found evidence of atherosclerosis in your arteries, the advice today about aspirin is clear and gender neutral: A daily dose will reduce your chances of dying of heart attack or stroke. Although there are still some doubts about the optimal dose, most studies show that small doses are just as effective — and maybe even more so — than large doses, so the standard advice is to take 75 to 162mg daily. In the United States and the Philippines, low-dose aspirin comes in 81-mg pills, which is basically the amount found in a “baby aspirin” tablet. In Europe, a 75-mg pill is available.

It’s more confusing — and not so gender neutral — for people who haven’t had a heart problem. However, there is some agreement that age is important. When researchers broke down their results by age groups, they found aspirin did reduce the risk of heart attack and stroke for women 65 years and older. Thus, when the American Heart Association revised its prevention guidelines for women last year, it recommended that healthy women who are younger than 65 should not routinely take aspirin to lower their risk of heart attack but that women 65 years and older should consider doing so after weighing the risks and benefits (it’s best to do that with the help of your doctor).

Risky Business

If aspirin were a completely benign drug, who takes it — and at what dose — wouldn’t matter much. But it has unwanted side effects that can offset its benefits. This means aspirin isn’t the kind of drug to start taking on a whim without first talking with your doctor — just because you can buy it over-the-counter without a physician’s prescription.

By inhibiting the cyclooxygenase (COX) enzyme, aspirin blocks the production of thromboxane, a substance in blood platelets that helps them stick together. This helps prevent the formation of blood clots in the blood vessels supplying the heart and brain, but it also increases the risk of bleeding. In the stomach, aspirin exerts a different effect and has the potential to weaken the protective barrier between the stomach’s delicate tissues and caustic gastric acids, which may in turn lead to fatal ulcers. Aspirin use has also been linked to hemorrhagic stroke, which occurs when the wall of a weakened blood vessel burst. This sounds scary but the protective effects of aspirin therapy are so great and the risks are so relatively small for most people, that it remains an essential part of preventing cardiovascular complications.

Facts About Aspirin

Before taking aspiring for any condition, here are some important facts you should know:

• Time it right. Ibuprofen (Brufen, Motrin, Advil, Alaxan, and others) blocks aspirin’s entry into the COX-1 pocket. So if you take aspirin for your heart and ibuprofen for arthritis, take the aspirin first and wait for at least 30 minutes before taking ibuprofen. If that isn’t possible, hold off on the aspirin for eight hours or so before taking ibuprofen. Other non-steroidal anti-inflammatory drugs may have the same effects as ibuprofen.

• Aspirin’s effects aren’t universal. Some people’s platelets respond beautifully to aspirin; other people’s platelets don’t. Genes, other drugs, and whether aspirin is taken regularly, can all influence its platelet-unsticking effect.

• Be alert for an aspirin allergy. About five percent of people with asthma have an allergy to aspirin. It can cause a stuffy or runny nose, wheezing or other breathing problems, a flushed face, or swelling inside the nose.

• It isn’t for kids. Don’t give aspirin to a child or teenager, especially one recovering from chicken pox or flulike symptoms. In rare cases, aspirin can cause Reye’s syndrome, an illness that affects the blood, liver, and brain of someone who recently had a viral infection.

• It can interact with dietary supplements. A variety of herbal medicine and dietary supplements affect platelets or influence the body’s ability to absorb aspirin. Common ones include omega-3 fatty acids (such as those in fish oil capsules), vitamin E, garlic capsules, policosanol, ginkgo, and tamarind. If you take aspirin, or plan to, make sure your doctor knows all the medications, over-the-counter remedies such as Kaopectate, and herbs and supplements you are taking.

Decisions, Decisions

So, if you have no problems in taking aspirin, here are some pointers that should help you decide whether you should be taking a low-dose aspirin regularly.

• First, talk with your doctor. Even in the low doses needed for cardiovascular protection, aspirin can cause gastrointestinal bleeding and increases the risk of hemorrhagic (“bleeding”) stroke. An informed doctor can help you balance these risks — which in absolute terms are pretty small — against the benefits.

• There’s no controversy if you’ve had a heart attack or some other major cardiovascular event. There’s solid evidence for both men and women that taking aspirin regularly lowers the risk of having a second heart attack or stroke.

• The greater the cardiovascular risk, the greater the benefit. The men and women who had the most to gain from taking aspirin are those with major cardiovascular risk factors.

• Men should consider taking aspirin at a younger age. Men with risk factors for cardiovascular disease need to start thinking about taking aspirin when they turn 40.

• No need for high doses. Low doses (e.g. 81mg daily) are just as effective as higher ones, and they’re also less likely to cause gastrointestinal bleeding.

Recommendations

So that you would have an idea of where you stand with aspirin use before going to your doctor, here’s a summary of the recommendations for the use of aspirin in various situations, from being in the midst of a heart attack to being healthy with no sign of heart disease.

• Heart attack in progress. If you think you are having a heart attack, take one plain, regular-strength (325mg) aspirin, or four baby aspirins if that’s all you have on hand. Chewing the tablet(s) gets the aspirin into your bloodstream faster than just swallowing the aspirin whole.

• Prior heart attack or stroke. Having had a heart attack, ischemic stroke, or transient ischemic attack (TIA) means you are prone to having another one. Virtually everyone in this camp should be taking aspirin every day — unless, of course, there is reason not to, such as an allergy to aspirin or the use of medications that might interact with it.

• Existing cardiovascular disease. If you have been diagnosed with angina (chest pain brought on by exertion or stress), peripheral artery disease, an abdominal aortic aneurysm, or cholesterol-narrowed coronary or carotid arteries, the latest recommendations encourage you to take aspirin daily.

• No diagnosed cardiovascular disease. This is where things start to get fuzzy. Here, you need to consult your doctor who can help you weigh the benefits and risks of aspirin therapy for you.

• Diabetes. When it comes to the circulatory system, diabetes is on a par with angina or artery clogging atherosclerosis as a risk factor for heart disease. The American Diabetes Association recommends a daily low-dose aspirin for all individuals with type 1 or type 2 diabetes who are over age 40, as well as those ages 30 to 40 who have other risk factors, such as high blood pressure, high cholesterol, a family history of heart disease, or protein in the urine.

• Kidney disease. Chronic kidney disease is also strongly linked to heart disease. Although there isn’t nearly as much information on this as there is for diabetes, the National Kidney Foundation recommends that people with kidney disease, especially those who require dialysis, take a daily aspirin.

• At risk for heart disease. A variety of factors can predispose you to atherosclerosis, the disease that underlies heart attacks and most strokes. These include having a parent or sibling who had a heart attack at a young age (under 55 for a man and under 65 for a woman), smoking, having high blood pressure or cholesterol, being substantially overweight, or not exercising. One or more of these plus older age – over 55 for men or over 65 for women – tips the balance toward taking aspirin. The more risk factors you have, the more you stand to benefit from aspirin.

• Low risk for heart disease. If you are healthy, haven’t been diagnosed with cardiovascular disease, and don’t have risk factors for it, aspirin probably isn’t for you. You’ll reap little good from it while exposing yourself to its risks.

Source: Philippine Star