A Valentine’s Day Primer…Making Sense of the New Cholesterol Guidelines
The American Heart Association and American College of Cardiology recently released new guidelines about treatment with cholesterol lowering medications to reduce heart attack or stroke. The experts who developed these guidelines reviewed and interpreted more than one hundred studies related to lowering blood cholesterol and noted several things.
First, the only cholesterol lowering drugs that have been shown to consistently reduce the risk of heart attack or stroke are medications called “statins”. These include Pravachol (pravastatin), Zocor (simvastatin), Lescol (fluvstatin), Lipitor (atorvastin), and Crestor (rosuvastatin).
Second, studies have shown that because the dose of the medication used correlates with the reduction in cardiovascular risk, for people at high risk to develop heart disease or stroke, using the highest tolerated dose of a statin medication is recommended.
Third, not everyone needs to be treated with a cholesterol lowering medication, and more than just the blood cholesterol value goes into the decision about whether a statin medication is necessary. Previous guidelines recommended that people with specific LDL-C cholesterol levels, such as more than 100, 130 or 160 be treated with a cholesterol lowering medication. However, the new guidelines recommend that the decision about whether to prescribe or take a medication should be based on a person’s likelihood of developing heart disease or stroke over the next ten years, not just on a blood cholesterol level. Risk for developing heart disease or stroke over ten years is calculated using a formula that is based on evidence from following a large number of different patients over many years to learn about factors that can predict the likelihood of developing cardiovascular disease.
When the guidelines writing group members reviewed the scientific studies they found that that there are four groups of people who benefit the most from taking a statin medication to lower cardiovascular risk. These groups are:
People who have already had a cardiovascular event, such as stroke, TIA, heart attack, CABG, stent, or have angina or peripheral artery disease
People with a blood LDL cholesterol greater than or equal to 190 mg/dl
People with diabetes who are age 40 to 75 with a blood LDL cholesterol 70 to 189 mg/dl
People with an estimated ten-year cardiovascular risk greater than or equal to 7.5% who also have a LDL cholesterol between 70 ad 189 mg/dl.
Side effects from statin medications can be muscle discomfort and abnormal liver function tests that go away when the drug is stopped. The frequency of these side effects is very low. However, because side effects do exist, people who are not in the four groups listed above are not encouraged to take statins. Their risk for cardiovascular events is low and the risk of a side effect from taking the drug may be higher than the risk of developing a heart attack or stroke. Statin medications only work if they are taken every day and need to be used over many years, which is why they are not generally recommended for young people or for those with low risk for cardiovascular events.
Obviously, the foundation for cardiovascular risk reduction is lifestyle – adhering to a heart healthy diet, regular exercise habits, avoiding tobacco products, and maintaining a healthy weight. However, for people at highest risk, adding statin medications to lower cholesterol has been shown to decrease their chances of having a heart attack or stroke. These new guidelines offer a framework for doctors and patients to use to make educated and reasonable decisions about prescribing and taking cholesterol lowering medications.
For those interested in more information, refer to the American College of Cardiology’s CardioSmart website at https://www.cardiosmart.org/Heart-Conditions/Guidelines/Cholesterol
- Marjorie King, MD, FACC, MAACVPR
- Director of Cardiac Rehabilitation Services