March 25, 2015
Statin Undertreatment for Middle-Aged, Overtreatment for Older Patients?

Durham, NC—Based on new statin guidelines issued in 2013, the cholesterol-lowering therapy was recommended for about 13 million additional Americans, including nearly everyone over 60. A new study finds, however, that those recommendations may have excluded too many middle-aged adults who could benefit from the drugs while creating over-prescribing in older adults.

The study, published recently in the Journal of the American College of Cardiology, suggests that small adjustments to the guidelines could mean more patients between ages 40 to 55 with premature heart disease would be treated, while unnecessary medication for many people over 65 would be avoided.

“The recommendations appear to be one-size-fits-all for patients in a variety of groups,” said senior author Michael Pencina, PhD, of the Duke Clinical Research Institute. “We were interested in how tailoring the guidelines could get beneficial treatment to those who really need it, and avoid over-treating patients whose risk may only be their sex and age.”

The sometimes controversial guidelines, issued by the American Heart Association and the American College of Cardiology, use age, sex, race, cholesterol and blood pressure levels, past treatments of hypertension, and smoking history to calculate a person’s risk of developing heart disease in the next 10 years. The guidelines recommend that any patient whose 10-year risk is calculated at 7.5% or higher should be treated with statins.

After applying the new guidelines to 3,685 participants in a leg of the Framingham Heart Study that began in 1975, Duke researchers found that basing treatment on a risk of 7.5% would have missed more than half of participants ages 40 to 55 who ended up with heart disease and may have benefited from statins.

At the other extreme, meanwhile, current guidelines would have over-recommended statins for many adults over age 60; a large portion of those patients continued to be tracked for the next 10 years and never developed heart disease.

The study found that basing statin therapy recommendations on a 10-year fixed risk threshold of 7.5% results in lower statin consideration among women than men (63% vs. 33%), while recommending the overwhelming majority of those aged 66 to 75 years (90.3%) for treatment.

“The fixed 7.5% threshold also had relatively low sensitivity for capturing 10-year events in younger women and men (aged 40-55 years). Sensitivity of the recommendations were substantially improved when the treatment threshold was reduced to 5% in those aged 40-55 years (changing sensitivity from 36% to 61% in women, and 49% to 71% in men),” the authors note.

At the same time, when the treatment threshold was raised to 10% in women and 15% in men for those aged 66 to 75, specificity significantly improved, with only a small to no loss in sensitivity, they add.

While current statin guidelines offer little flexibility, shifting the treatment targets could create better outcomes, said lead author Ann Marie Navar-Boggan, MD.

“The guidelines don't perform particularly well in younger people,” Navar-Boggan said, suggesting that lowering the treatment threshold for patients ages 40 to 55 to those with a 5% risk or greater could capture more middle-aged adults who develop heart disease early. Yet, that might not be enough, she cautioned, because factors such as family history are not taken into consideration.

“We found that by raising that threshold to 15%, the guidelines could identify the same proportion of men who will go on to have heart disease, but would reduce treatment for those who will not. This would help eliminate unnecessary drug treatment for many patients,” she said.
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