Statin adherence remains low in post-MI, high-risk patients

A study published Jan. 8 in the Journal of the American Heart Association suggests patient adherence to statin therapy in the U.S. remains low, particularly among younger individuals, minorities and those recommended for high-intensity regimens.

Lead author Lisandro D. Colantonio, MD, PhD, and colleagues wrote that following persistent evidence that statins reduced the risk of coronary heart disease (CHD) in certain patients, the American College of Cardiology and American Heart Association included the drugs in their 2013 recommendations for reducing atherosclerotic cardiovascular disease (ASCVD) risk in adults. The ACC and AHA encouraged patients with CHD to take statins, as well as those with dangerously high LDL cholesterol levels, diabetes or a high 10-year predicted risk of ASCVD.

“Adults who have low adherence or who discontinue statin therapy have an increased risk of CHD events compared with their counterparts with high adherence to statins,” Colantonio, of the University of Alabama at Birmingham, and co-authors wrote. “Observational studies have suggested that a high proportion of adults initiating statins have low adherence or discontinue treatment.”

But most of those studies used data collected before 2005, the authors said, and the prevalence of statin therapy has increased significantly since then.

Colantonio et al. undertook a retrospective study of millions of statin users with commercial or government health insurance who initiated treatment between 2007 and 2014. The team tracked 201,573 patients who began using statins after an MI; 610,049 patients who had diabetes but no CHD; and more than 2.2 million who had neither CHD nor diabetes. Researchers assessed adherence according to patients’ pharmacy fills in the year following their initiation of statin therapy.

In 2007 and 2014, respectively, 78.1 percent and 79.1 percent of patients in the post-MI cohort demonstrated persistence in taking their statins. Those same years 66.5 percent and 67.3 percent of diabetics, respectively, showed adherence, while 64.3 percent and 63.9 percent of those free from diabetes and CHD demonstrated adherence.

Between 2007 and 2014, Colantonio and colleagues said high adherence to statin therapy increased from 57.9 percent to 63.8 percent in the post-MI group and from 34.9 percent to 37.6 percent in the diabetes group, but there was no improvement in patients without CHD or diabetes.

In 2014, adherence was lowest among young patients, black and Hispanic patients, and those initiating a high-intensity dosage. It was highest among men and patients who received cardiologist care after they began taking the drugs.

“Prior studies have suggested improvements in adherence to statin therapy following an MI over the past 25 years,” the authors wrote. “Results from the current analysis highlight the need to improve persistence with and adherence to statin therapy if the CHD risk reduction benefits of statins demonstrated in clinical trials are to be translated into clinical practice.”

Colantonio et al. said patients with a low adherence to statins were also likely to have a worse track record with taking their antihypertensives and other medications. Cost issues, cultural beliefs, fear of toxicity and apprehension about adverse side effects might also contribute to low persistence.

The authors wrote clinician-led interventions, like nurse-administered risk factor counseling, drug-regimen simplification, reminders and phone calls could help improve statin adherence across the country.

“Low persistence with and adherence to statin therapy constitute major concerns because they are associated with substantial residual risk for CHD events,” they said. “Healthcare providers should monitor statin use following initiation of treatment and work with patients to identify barriers to taking this medication with high adherence.”