The American Heart Association and American College of Cardiology recently released new guidelines that call for sweeping changes in the way cholesterol-lowering statin medications are prescribed. These new guidelines have caused much controversy, as physicians across the country debate the science behind the new recommendations, the merits of changing decades-old practices, and the idea of placing even more of their patients on statin therapy.
Dr. Eric Lieberman, Suburban Hospital's chief of the Division of Cardiology, sheds some light on the new guidelines and the use of statins to prevent and treat cardiovascular disease.
What do patients need to know about the new guidelines?
The biggest change with the new guidelines involves how physicians will calculate risk. Previously, statin therapy was recommended for patients whose 10-year risk of a cardiac event was determined to be 10 percent or higher. This number was determined using a risk calculator that weighed such factors as an individual’s age, gender, cholesterol levels, blood pressure and blood pressure medications, and smoking habits. The new guidelines incorporate a revised risk calculator that some critics claim will overestimate risk. According to the new guidelines, the population of patients now deemed to be appropriate candidates for statin therapy has been redefined to include individuals whose 10-year risk of a cardiac event or stroke is 7.5 percent or higher. Because this is a lower threshold than the previous guidelines, there is the potential that millions more Americans will now be advised to begin statin therapy.
There are positive aspects to the 2013 guideline revisions. For the first time, recommendations are based upon studies that include ethnic minorities, so the new guidelines may be more applicable to people of color. In addition, previous guidelines considered only the risk of heart attack while these guidelines include estimates of stroke risk in addition to the risk of cardiac problems.
Why have the new guidelines caused so much controversy?
While there are some good aspects to the guidelines, such as the factors mentioned above, they also have significant shortcomings. Overall, I believe they are a step back from the progress that has been made in this area.
The new guidelines abandon hard number targets for LDL (or "bad") cholesterol, stating instead that the goal of treatment should be to lower LDL cholesterol between 30 percent and 50 percent. I believe this does a disservice to patients. Numerous studies have shown that achieving an LDL of 70 mg/dl or below may delay or reverse the progression of atherosclerotic coronary disease.
The new guidelines also fail to consider the advancements that have been made in the area of cardiac imaging. For example, the coronary calcium score tells us how much calcium is in the walls of the coronary arteries. Calcium deposits are associated with the presence of atherosclerotic plaque. A calcium score of zero indicates a much lower risk than a calcium score of 200, even when comparing individuals with the same cholesterol level. The higher the calcium score, the higher the risk of developing heart disease and experiencing a cardiac event.
Another imaging test, carotid ultrasound, assesses the risk of a heart attack or stroke by determining the thickness of the walls of the carotid arteries. The new guidelines discount the value of these imaging tests, whereas there had been hope that the new guidelines would recognize their value in enhancing our ability to detect cardiac risk. In the end, individual physician judgment should supersede any new recommendations.
How do you determine who needs to be on statin medication?
A review of the patient’s medical history is always the first step in my evaluation, followed by a review of a complete family history. I then examine the patient’s lipid profile. For instance, if a patient has a normal LDL-cholesterol but his father had a heart attack at age 50, the family history confers an increased risk of future heart attack even in the setting of a normal lipid panel. This patient may require a more in-depth evaluation, and in this situation I will often obtain a coronary calcium score.
What hasn't changed is the recommendation that patients who have been diagnosed with coronary disease or diabetes, or those with a history of prior stroke, should be on statin medication. This highlights the importance of obtaining a detailed review of the patient’s medical history.
I have just been diagnosed with high cholesterol. Will my doctor put me on a statin immediately?
In a patient with newly diagnosed high cholesterol, it’s important to rule out any underlying cause for the increase in cholesterol level. For example, some medications, such as birth control pills, may raise cholesterol levels. Similarly, other illnesses may be to blame for a rise in cholesterol levels. These include thyroid and kidney disease. Your physician should take a look at your other medications and illnesses before making a recommendation regarding statin therapy. Any decision about the use of statins should be based on a detailed discussion with your physician.
I am on statin therapy. How often should I have blood tests?
In stable patients, a lipid panel should be performed annually. If a statin has just been introduced or a dose change has been made, then the lipid panel should be repeated four to six weeks later, and then annually. Last year the FDA removed the recommendation to check liver enzymes every six months for stable asymptomatic patients because the risk of developing drug-induced liver abnormalities is so very low.
Are statins safe for long-term use?
The good news about statin drugs is that they are very safe, have no cumulative toxicity, and don’t become less effective over time. Statins are the cornerstone of the cholesterol-lowering drugs. While other drugs can lower cholesterol, only statins have been proven to lower cholesterol and reduce the risk of heart attack or stroke.
There are some instances where statins may cause inflammation of the liver, which is reversible once the drug is discontinued. They may also cause muscle soreness. Those individuals who develop achy muscles while on one statin may respond well to a lower dose of the same statin or to a different statin. Muscle damage is a very rare complication.
Physicians will weigh the benefits and risks of statin therapy against the risk of a cardiac event or stroke. For patients who cannot tolerate statin therapy, we will consider the use of another drug to lower cholesterol while re-emphasizing lifestyle changes that include a heart-healthy diet and physical activity.
What lifestyle changes should I make to avoid statin therapy or in addition to statin therapy?
A Mediterranean diet reduces the risk of developing cardiovascular disease. This diet is rich in fish, vegetables, whole grains, olive oil and nuts, and very low in red meat. In fact, red meat should be limited to once per month.
It’s also extremely important to be physically active for at least 30 minutes per day at least five days per week. This activity can include walking, biking, swimming, or another form of aerobic exercise. In addition to maintaining a healthy diet and exercising, don’t smoke and control your weight and blood sugar, especially if you have diabetes.
There is a risk with these new guidelines that it will be too easy for some people who are put on statin therapy to think that all they need to do to avoid a heart attack or stroke is to take a pill. While taking a pill to lower your risk is convenient, I can’t overemphasize the importance of lifestyle changes. Even for those patients who are already on statin therapy, maintaining a healthy lifestyle is critical to ensuring your long-term health.
About Dr. Eric Lieberman
Dr. Lieberman graduated with high distinction from the University of Virginia. He received his medical degree from Emory University School of Medicine. He performed his internship and residency at the Johns Hopkins Hospital and completed a fellowship in cardiovascular disease at Duke University. After serving as a cardiologist and major in the U.S. Air Force, Dr. Lieberman returned to his native state of Maryland. He is board certified in cardiovascular disease and interventional cardiology.
Dr. Lieberman is affiliated with Johns Hopkins Community Physicians Heart Care, located at 15005 Shady Grove Road, Suite 340, in Rockville. The phone number is 240-238-3760.