Last fall, the American College of Cardiology (ACC) and the American Heart Association (AHA) released new guidelines for the treatment of cholesterol to prevent heart attacks and strokes, amid a continuing rise in the rate of heart disease in the United States.
Though the guidelines were years in the making and have received a large amount of media attention, questions and confusion about certain aspects of the guidelines remain. Some new research shows that the guidelines measure heart disease risk in a way that makes nearly all seniors eligible for cholesterol-lowering statin drugs.
Rules Do Away with Cholesterol Targets
One of the biggest changes from the previous standards is that cholesterol targets — specifically, a numeric goal for levels of LDL, or “bad,” cholesterol — were eliminated.
“Our guidelines did not endorse specific, arbitrary targets,” said Dr. Neil J. Stone, chair of the expert panel that finalized the new guidelines in 2013. “This was the big paradigm shift, and some clinicians still have difficulty understanding why we did it. We simply couldn’t find the hard evidence that having a fixed target made a difference.”
One reason for ditching those targets is the somewhat arbitrary nature of the cut-off point — set at a blood LDL level of less than 100 mg/dL or the optional goal of less than 70 mg/dL. While the best treatment course for people with very high LDL levels is clear, clinical decisions become more challenging the closer you get to the cut-off. People with a low-risk condition but an LDL level just above the target might receive unnecessary therapy, while high-risk patients just below the cut-off might not receive beneficial treatment.
While the lack of specific targets in the new guidelines bothers some doctors, subsequent research supports the guideline committee’s decision.
“Our stance was supported by a study that looked at successive patients who had CT angiograms” to measure heart and blood vessel function, said Stone, “and this showed that our risk-based guidelines more accurately assigned those with heavy plaque [buildup in their blood vessels] to statins, and avoided statins for those without plaque — compared to the previous guidelines with LDL thresholds.”
Other doctors agree that though having targets provided something to shoot for, there are better ways to improve heart health.
“We need to focus on treating high risk, not high cholesterol,” said Dr. Adam M. Cohen, a noninvasive cardiologist and director of the preventive cardiology and dyslipidemia program at Abington Medical Specialists in Abington, Pennsylvania. “I think these guidelines are in a lot of ways trying to say the same thing a little more practically.”
Risk management, rather than focusing solely on lowering cholesterol, means looking at someone’s entire risk profile, which includes whether they have high blood pressure or established heart disease, are current or former smokers, or have a strong family history of the disease.
“Based on that,” said Cohen, “you decide how aggressive you want to try to treat their [cholesterol].”
Statins Should Go Only to ‘High-Risk’ Patients
Instead of LDL targets, the guidelines identify groups of people who are at high risk of having a heart attack or stroke. These are the people most likely to benefit from medications or lifestyle changes.
- people with existing heart disease
- people with an LDL level of 190 mg/dL or higher
- people between 40 and 75 years of age who have type 2 diabetes
- people between 40 and 75 years of age who have a 10-year risk of heart disease that is 7.5 percent or higher
In the first three groups, doctors do not need to estimate the risk of cardiovascular events. These people automatically qualify for statins.
“I think for three of these groups, there’s been widespread consensus,” said Cohen. “Where most of the discussion is occurring is in that fourth group, which is basically based on the risk calculator.”
For the fourth group, which includes people without any strong symptoms of heart disease, the guidelines committee used data from the latest scientific studies to develop a risk calculator. This tool allows doctors and patients to determine both their 10-year and lifetime risk of cardiovascular disease, including heart attack or stroke and death from either of those causes.
In spite of its strong basis in science, the risk estimator has drawn criticism from some doctors.
One risk factor that isn’t accounted for in the ACC/AHA risk calculator is family history, mainly because it is difficult to translate into a number, although it’s something doctors keep in mind when discussing cholesterol treatment with patients.
“It’s kind of a one-size-fits-all risk calculator, and it overemphasizes some aspects of risk and it ignores others,” said Cohen. “Age tends to be a very big predictor there, so almost any very elderly patient is going to meet criteria on the basis of that alone, or that plus hypertension or other factors. That was a source of confusion for a lot of people.”
In fact, a recent study in JAMA Internal Medicine found that up to 97 percent of people between the ages of 66 and 90 qualify for statins under the new guidelines and according to the accompanying risk calculator.
This highlights one major area of debate — the apparently large increase in the number of people, especially asymptomatic people, who will be prescribed statins. Statins are not without side effects. These include muscle pain, confusion, flushing, and rarely liver damage or memory loss.
The guidelines are clear about which groups of people could benefit most from therapy — both medications like statins and lifestyle changes like eating better and exercising more — but in the fourth group, the guidelines leave room for doctors and patients decide together how best to lower cholesterol levels.
“One of the key parts of the guidelines is that a clinician-patient discussion should occur before initiating statin therapy for lower risk primary prevention,” Stone said. “What that means is, in certain cases, the patient and clinician may decide not to use a statin.”
Of course, that is the very nature of guidelines, something that has been lost in the media shuffle over the past year.
“You have to use information provided by guidelines,” said Cohen, “but also use the information that you have as a physician, based on looking at other risk factors that are not included.”
The risk estimator, because it triggers a conversation between a patient and doctor, also serves as an excellent reminder to take a look at a patient’s current lifestyle and risk factors for heart disease. If the 10-year risk is high enough, the doctor and patient can talk about the benefits and side effects of medications like statins, with the ultimate decision in the patient’s hands.
Doctors Still Need to Monitor Patients Long-Term
Another aspect of the guidelines that has created some confusion is the belief that, because there are no more LDL targets, doctors no longer need to do ongoing monitoring of LDL blood levels after a patient starts taking a statin. This is not the case.
“Ongoing monitoring is required,” Stone said. “Even though we don’t have fixed targets, we do have goals. And the goal is to maintain the optimal intensity of proven therapy in order to keep LDL lower in groups that are shown to benefit.”
Hitting the LDL target was just one reason for monitoring. “I think having your cholesterol checked is a good reinforcement to patients,” Cohen said. Some patients may not respond well to statins or they may have bad side effects. And some patients don’t take their medication as prescribed, which may warrant a conversation with their doctor about the importance of lifestyle changes.
Eating well and exercising have always been part of maintaining healthy cholesterol levels. However, because the new guidelines go into such depth about the use of statins to control cholesterol, some people feel that discussions about lifestyle have fallen by the wayside.
However, in addition to the risk estimator providing an icebreaker between doctor and patient to talk about diet and exercise, the ACC/AHA committee also released other guidelines last year focused on lifestyle and obesity. The guidelines include therapies supported by many doctors.
“I make sure that with all my patients when we’re even considering drug therapy, they have to understand that statin use is on the backdrop of aggressive lifestyle modification,” Cohen said. “That you can’t just take a statin and sit on your butt and eat cheesecake.”