Many doctors already prescribe statins to people who have not yet had a heart problem, but figuring out who might benefit most from the drugs is a challenge.
The U.S. Preventive Services Task Force (USPSTF), a panel of experts that is commissioned to comb through existing studies of health issues and come up with recommendations, attempts to address that question with its latest advice. The group says that the weight of evidence suggests that statins can help middle-aged people who have not yet had heart problems avoid them if they have a greater than 10% risk of having a heart attack or stroke in the next 10 years.
But some people think the recommendations do little to clarify the situation.
Doctors can calculate their 10-year risk by plugging certain information into a web-based calculator formulated by the American Heart Association (AHA) and the American College of Cardiology (ACC). In 2013, the two groups debuted this revised algorithm, along with their recommendation that people with a 7.5% or greater risk of heart events in the next 10 years consider taking a statin to reduce that risk. In their previous advice, based primarily on the so-called Framingham risk factors that emerged from a decades-long study of what contributed to heart disease, the experts set the statin threshold at a 10% or greater risk. The lower cutoff made millions more people eligible to take a statin and created controversy, as some heart doctors questioned whether all of those people would actually benefit—especially since the drugs carry some side effects, including muscle problems and a possibly higher risk of diabetes. Some cardiologists argue that those risks aren't worth it for people who do not yet have any symptoms of heart disease.
The USPSTF recommendation suggests that some of that skepticism might be warranted. Based on its review of the studies, the task force concluded that people with a 10% or greater risk of heart problems in the next 10 years, based on the 2013 AHA-ACC calculator, and who have diabetes, high cholesterol, high blood pressure or who smoke, can lower their risk of having a heart attack or stroke by a “moderate amount” by taking a statin.
They decided that people with a 10-year risk that falls between 7.5% and 10% could also benefit from the drugs, but perhaps not as much as those with 10% or greater risk. The panel found that these people could reduce their heart risk by “a small amount.”
In other words, the group found that everyone whose risk is 7.5% or greater would benefit, but, “the magnitude of the benefit is different the greater the risk," says Dr. Douglas Owens, a member of the USPSTF panel and professor of medicine at Stanford University. "Heart disease risk is a continuum, so the higher your risk, the more likely you will benefit from taking a statin.”
Even though the previous AHA-ACC guidelines recommended statin discussions start at a lower threshold, "these recommendations are absolutely consistent with the ACC and AHA guidelines,” says Dr. Mark Creager, president of the AHA. “They give a little more discretion to doctors for people with 7.5% risk, which is perfectly appropriate. But the two statements are really quite consistent with each other. They don’t conflict.”
Not everyone will agree. The two statements might seem especially confusing to the health-conscious public trying to protect themselves from a heart event. Does the new advice mean that people whose risk falls between 7.5% and 10% should wait, in some sort of heart-health limbo, until their risk rises to 10% before seriously considering a statin? Or does it mean that anyone with a risk 7.5% or higher should just take a statin?
“What we have here is another opportunity for confusion,” says Dr. Steven Nissen, chair of cardiovascular medicine at Cleveland Clinic. “These recommendations leave as many questions as they give answers, and it just doesn’t help. It doesn’t clarify for prescribers and for patients what they should do. I find that exasperating.”
Nissen notes that the USPSTF risk is calculated based on the controversial 2013 AHA-ACC formula, which does not include family history in its algorithm. Other than age, he says, family history is a major contributor to heart disease risk.
The USPSTF panel also concluded that there is insufficient evidence to recommend statin use to prevent first heart problems among people over age 75. Given that the risk of heart disease goes up consistently with age, “we should be offering the same treatments to people over 75 as we do to people who are younger,” says Nissen. “To do less in a society where more and more people are living to advanced age, I believe that’s the wrong thing to do.”
In a separate analysis, the panel also looked at evidence for using statins in young children, and concluded that there isn’t strong enough scientific data to support prescribing the drugs in children and adolescents. That’s counter to the strong push by the American Academy of Pediatrics to screen more young children for high cholesterol levels and consider statins for those with genetic mutations that put them at higher risk for excessively high cholesterol levels.
Owens says that the task force’s intention was to “give additional guidance to clinicians and patients. The main message is that people with elevated risk can benefit from taking a statin.”
But the question of when those people should start their therapy remains just as unsettled as it was before. Creager says that the AHA and ACC are in the process of convening its next guidelines panel that will take another look at all the evidence, including any new information published since their 2013 advice, and revise their guidelines if necessary. “Science is iterative, and as new information comes in, we look carefully at it, consider it, and our recommendations and guidelines may change,” he says. In other words, stay tuned for more news about statins.