High cholesterol is a key contributor toward an individual’s cardiovascular disease risk. Health care providers are now using a new set of guidelines published in November 2018 that may change diagnosis and treatment of “high” cholesterol in people of all ages. This new set of guidelines, issued by the American Heart Association, American College of Cardiology and other medical societies, has important implications for your cholesterol levels and for your heart.
Here is a breakdown of how cholesterol affects you, when you should receive treatment, what kinds of treatment you may need and the top 10 key points from the new guidelines.
What is cholesterol, and why is it dangerous?
Cholesterol is a waxy, fat-like substance found in all cells in the body. The body naturally produces cholesterol, or it’s ingested from food in the diet. Some cholesterol is necessary, as your body needs cholesterol to make important hormones and bile acids, which help absorb fat during digestion. But, too much cholesterol in the bloodstream can deposit into the lining of the arteries, causing plaques to build up — a condition called atherosclerosis.
These cholesterol-rich deposits eventually attract inflammatory cells and calcium, and over time, plaque grows into blockages that can obstruct blood flow. Symptoms occur when plaque prevents oxygen-rich blood from passing through blood vessels. Even more dangerous, occasionally plaque can break off or be disrupted, causing a blood clot to form suddenly and obstruct an artery. If this happens in one of the arteries supplying blood to the heart or brain, the person may suffer a heart attack or stroke. Fortunately, since cholesterol is so critical to the process of cardiovascular disease formation, lowering your cholesterol can also prevent many different types of cardiovascular disease. Low-density lipoprotein cholesterol is the “bad” form of cholesterol most likely to contribute to heart disease, which is why it is the primary focus of cholesterol management in the new and prior guidelines.
How should I monitor and treat my cholesterol?
The AHA/ACC guidelines recommend evaluating cholesterol levels every four to six years starting at age 20. In older adults who have risk factors for cardiovascular disease or are on cholesterol therapy, these levels should be checked more frequently.
The decision to treat cholesterol with medication depends on one’s overall risk for heart attacks and strokes, and generally isn’t based on any specific LDL cholesterol value unless it is very elevated (more than 190 milligrams per deciliter). It’s important to note that while cholesterol is one major driver of atherosclerosis, other factors such as age, smoking, blood pressure, elevated blood sugar, inflammation and family history (genetics) also play key roles in atherosclerosis formation.
For people 40 to 75 years old who don’t already have known cardiovascular disease, calculators from the AHA/ACC are available to determine one’s 10-year heart attack or stroke risk. Using this calculator, people’s 10-year risk of cardiovascular disease can be classified as low (less than 5 percent), borderline (5 to 7.5 percent), intermediate (7.5 to 20 percent) or high (20 percent or more). One’s risk level guides treatment decisions for this age group (see below).
For adults older than 75, decisions to treat with cholesterol medication depend on the patient’s overall health condition and their life expectancy, as part of a shared decision-making process between the patient and their health care provider.
Younger individuals, ages 20 to 39, are encouraged to follow lifestyle changes for their primary management. However, younger adults would be strongly recommended for drug therapy if they have established cardiovascular disease or severely elevated cholesterol of 190 milligrams per deciliter or higher. They also may be considered for drug therapy if they have a strong family history of early heart disease or if their LDL cholesterol levels are more than 160 milligrams per deciliter.
What medications treat elevated cholesterol?
Statins are medications that reduce the liver’s production of LDL cholesterol. Different statins may have different tolerability and side effects. Similarly, the cholesterol-lowering effects of statins vary with statin type and dosage. Given the established benefit of statins in reducing heart attacks and strokes, health care providers recommend them as first-line medications to be used in patients at elevated cardiovascular risk.
However, in some individuals, cholesterol levels remain high despite adding maximal strength statins and lifestyle changes. In other people, statins can’t be tolerated due to side effects. The guidelines then recommend turning to second-line therapies in both these situations.
One of these second-line medications is ezetimibe, which reduces gut absorption of cholesterol. Ezetimibe doesn’t have as strong an effect as high-dose statins (it typically lowers LDL cholesterol by approximately 20 percent); therefore, it’s usually used as an additional therapy instead of as initial therapy.
When a statin and ezetimibe together fail to lower cholesterol levels appropriately, or can’t be tolerated, PCSK9 inhibitors are a third type of medication that may be used, but this therapy currently is reserved for only the highest risk patients or those with a severe LDL cholesterol abnormality. PCSK9 inhibitors are injectable medications that work by allowing the body to clear LDL on its own. Currently, given high costs for this drug, burdensome pre-authorization paperwork for PCSK9 inhibitors is often a barrier for many patients to access this therapy.
Here’s what’s new: The top 10 take-away messages from the 2018 AHA/ACC cholesterol guidelines.
1) Lifestyle changes are the first step for everyone.
A healthy lifestyle will not only reduce cardiovascular risk, but will also reduce high cholesterol. No matter your current age or medical history, you can still change your cholesterol levels and overall cardiovascular risk by adopting healthy habits. Recommendations for a healthy lifestyle include quitting smoking, exercising at a moderate pace for 150 to 300 minutes per week, eating a heart-healthy diet and maintaining a healthy weight and waist circumference.
2) If you have established cardiovascular disease, clinicians recommend statins.
If you already have known cardiovascular disease — already had a heart attack, stenting of heart arteries, a stroke or peripheral artery disease — then you’re considered a “high risk” patient. In these cases, patients are recommended to take statins because this treats the plaque in the arteries even if the LDL cholesterol value isn’t that high. The goal of taking statins in these patients is to reduce the blood LDL cholesterol levels by at least 50 percent using the maximally tolerated dose to prevent another cardiovascular event.
3) If you’re at very high risk of cardiovascular disease, consider adding another cholesterol lowering medication to your statin.
“Very high risk” patients are those who have had a heart attack or stroke within the past 12 months, multiple past heart attacks or a prior heart attack with other high-risk conditions such as a history of peripheral artery disease. Among these individuals, for an LDL cholesterol level above the threshold of 70 milligrams per deciliter despite taking the maximally tolerated dose of statin, it’s reasonable to add another proven medication such as ezetimibe and/or PCSK9 inhibitors as mentioned above.
Is there an LDL cholesterol level that is “too low”? The answer is probably no; we now know that lower LDL cholesterol levels lead to better outcomes, though there’s probably no need to keep LDL cholesterol levels less than 20 milligrams per deciliter.
4) If you have severely elevated cholesterol, treat with one of the more potent statins at the maximum tolerated dose.
Those with LDL cholesterol levels at 190 milligrams per deciliter or more (which is usually the result of a genetic condition) have a significantly elevated lifetime risk of developing cardiovascular disease. Thus, regardless of one’s estimated 10-year risk, it’s recommended to treat with the maximally tolerated statin dose to reduce lifetime risk of cardiovascular diseases.
5) If you have diabetes, treat with a moderate intensity statin.
Patients with diabetes have a significant burden of cardiovascular and peripheral artery disease. Cardiovascular disease is the number one cause of death in patients with diabetes. Thus, health care providers recommend statins. A moderate intensity (dose) of statin is recommended, but patients with diabetes who also have significant risk factors for heart disease might benefit from a more intensive statin dosing.
6) If you don’t already have diabetes or heart disease, discuss whether statins are right for you with your health care provider.
If your physician determines that you’re at intermediate risk for cardiovascular disease and are between ages 40 and 75, your doctor should discuss the benefits and risks of starting a statin with you. If you only have mildly elevated cholesterol levels, it can be unclear whether a statin would be beneficial, or whether lifestyle adjustments would be sufficient. In these cases, it’s important to consider your individual risk factors prior to making a shared decision with your health care provider. This conversation should go over potential benefits of statins versus adverse side effects or drug interactions with other medications. Statins have a well-established safety record. For most intermediate and high-risk patients, the benefits of statins largely outweigh any potential risks.
7) An intermediate or high 10-year heart attack and stroke risk favors statin therapy.
For those without known cardiovascular disease or diabetes, an estimated 10-year heart attack or stroke risk of 7.5 percent or more is usually the tipping point that favors using statins for many individuals. However, this is a personalized decision and requires discussion with your doctor. Sometimes you need more information to make this decision.
8) Consider other risk-enhancing factors.
In adults with a borderline elevated 10-year heart attack or stroke risk of 5 to 7.5 percent, considering additional risk factors may support the decision to start statin therapy. Some of these factors include having a family history of early heart disease, having chronic kidney disease or an autoimmune disorder such as lupus or rheumatoid arthritis, or having a history of premature menopause or HIV infection. Also, having elevated levels of triglycerides, lipoprotein (a) or C-reactive protein, all of which your health care provider may test for, could provide evidence that a stain would be beneficial.
In those people with an intermediate 10-year risk of 7.5 to 20 percent, the presence of those factors might strengthen the decision to start a statin or prompt intensifying statin therapy to a higher dose for additional LDL cholesterol reduction.
9) If risk is still uncertain, a coronary artery calcium scan may help.
In adults with a calculated 10-year heart attack or stroke risk of 5 to 20 percent, even after considering other health factors, more information may be desired to help better understand an individual’s risk and the benefits to be gained with statin therapy. This is where a coronary artery calcium scan can help guide decision-making.
A coronary calcium score is an imaging test assessed by CT scan that calculates whether or not someone has hardened plaque deposits in the blood vessels of the heart. If the coronary artery calcium score is zero, a statin may not be needed. If the coronary artery calcium score is above zero, the guidelines recommend adding a statin, particularly for scores higher than 100 or if above the 75th percentile compared with other individuals of the same age and gender.
10) Monitor responses to medication and lifestyle changes.
Your health care provider should follow your response to drug therapy and lifestyle changes by evaluating what percentage your LDL cholesterol decreases from your baseline. After first starting a statin, follow-up cholesterol measurement should take place in four to 12 weeks. After that, there can be periodic monitoring every three to 12 months as needed, depending on dose adjustment. In “very high” risk patients, having a persistently elevated LDL cholesterol greater than 70 milligrams per deciliter might prompt consideration of those additional drug therapies mentioned above on top of your statin.
The 2018 guidelines are a major advancement from prior guidelines, emphasizing a more personalized approach to making decisions regarding cholesterol treatment. The new guidelines recommend considering not only estimated 10-year risk but also the individual’s additional health factors, and support evaluating for calcified plaque by CT imaging test when decisions remain uncertain.
In addition, there are new LDL cholesterol treatment targets, especially if the person already has heart disease. In intermediate-risk adults, health care providers should strive for an LDL cholesterol reduction of at least 30 percent when prescribed statins. In high-risk patients, cholesterol therapy should aim to reduce LDL cholesterol levels at least by 50 percent to an ideal LDL level below 70 milligrams per deciliter.
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