Recently, the American College of Cardiology and American Heart Association (ACC/AHA) updated guidelines in the United States for treating cholesterol, shifting the recommendations to allocate statins to those with a high absolute risk for cardiovascular disease (CVD). “The guidelines recommend using statins for people with CVD, diabetes, or high cholesterol levels,” explains Michael D. Miedema, MD, MPH. “They also advise clinicians to use these medications in patients without these conditions but with a higher than 7.5% risk of heart attack or stroke in the next 10 years based on risk calculator data.”
The updated guidelines represent a paradigm shift from the Adult Treatment Panel (ATP) III recommendations. The ATP III guidelines relied heavily on levels of LDL cholesterol to determine who to treat. The ACC/AHA guidelines recommend using statin therapy on patients who are at highest risk for heart attack and stroke, even if their cholesterol levels are within normal limits.
Examining the Impact of New Statin Guidelines
A recent study estimated that the ACC/AHA guidelines will lead to significant increases in statin use, largely because more adults aged 60 and older without CVD or diabetes will be eligible for these medications. Dr. Miedema says it is important to look at the effect that the ACC/AHA guidelines will have on older patients because they may be prone to adverse effects with statin use. “It can be challenging for clinicians to determine whether or not statins should be used in older, healthy patients,” he says.
In a research letter published in JAMA Internal Medicine, Dr. Miedema and colleagues analyzed the potential effect of the updated ACC/AHA guidelines and contemporary use of statins in older patients from the Atherosclerosis Risk in Communities (ARIC) study. The cross-sectional analysis involved more than 6,000 African Americans and Caucasian Americans between the ages of 66 and 90. The prevalence of indications for statin therapy was then analyzed according to ACC/AHA guidelines and ATP III guidelines, the latter of which were the most relevant guidelines at the time ARIC participants made their fifth study visit.
Greater Eligibility for Statin Use
According to the results, many ARIC participants used medications to lower their lipid levels, but uncontrolled hyperlipidemia was still common according to the ATP III guidelines that were then in place (Table 1). Patients with a high absolute risk for coronary heart disease (CHD)—defined as greater than 20% for 10 years—were the least likely to be at their LDL cholesterol goal. Those with one or zero risk factors for CHD were most likely to be at goal. Full implementation of ATP III guidelines should have resulted in treatment of about 70% of the study sample.
Conversely, using the ACC/AHA guidelines, 97% of ARIC participants aged 75 and younger met one of the four major indications for statin therapy, which included CVD, diabetes, LDL cholesterol levels above 190 mg/dL, and an absolute 10-year CVD risk of 7.5% or higher (Table 2). Among these patients, nearly half were taking a statin, but only 9% were taking a high-intensity statin. “There definitely will be an increase in statin eligibility for patients aged 65 to 75,” Dr. Miedema says. “However, the guidelines make it clear that being eligible for a statin should stimulate a discussion about the risks and benefits of these drugs as opposed to a strict mandate to take them.”
Importantly, the ACC/AHA guidelines do not offer a recommendation for or against statin therapy in people older than 75 because of a lack of evidence in this age group, says Dr. Miedema. “That said, more than half of the study participants in that age group were taking statins,” he says. “We need more data on the safety and efficacy of statins in patients who fall into this age range.”
Important Implications With CVD Risk Factors
Older individuals will likely cross the 7.5% threshold based on age alone, even if they have normal cholesterol levels and no other CVD risk factors, according to the study. Dr. Miedema and colleagues noted that the 7.5% CVD risk threshold is aggressive in that it creates a nearly universal recommendation for statin use among patients between the ages of 65 and 75. “Although older people are naturally at higher risk for heart attacks and strokes, it’s still important to assess the risks and benefits of statins in these patients.”
Dr. Miedema says it is encouraging that older patients are taking statins more often than other medications to lower their lipid levels but notes that the optimal role for statin therapy in the elderly must be further explored. “We need more research to help define ideal older candidates for statin therapy,” he says. “This research may enhance our ability to reduce the risk of heart attacks and strokes in older patients while simultaneously avoiding treatment in individuals who are unlikely to benefit from a preventive medication.”
TimH
