Peripheral Artery Disease Statin Adherence Near 20% at 5 Years

Peter Toth, MD

Wavering long-term statin adherence rates continue to be a headache for clinicians.

In a new study presented at the 2019 American College of Cardiology (ACC) 2019 Annual Meeting in New Orleans, LA, investigators reported five-year statin persistence rates of just more than 21% among patients with and without baseline peripheral artery disease (PAD) and/or elevated triglyceride levels.

The study—led by Peter Toth, MD, PhD, director of Preventive Cardiology at CGH Medical Center and a clinical professor at the University of Illinois—adds to a decades-long trend of analyses showing that prescription statin adherence is essentially a coin flip among patients after just 1 year.

“This is fascinating, because if you look back to a JAMA study in 2002, it shows the same thing—at 6 months only 50% are adhering,” Toth said. “It hasn’t improved. Since 2013, the incidence of cardiovascular mortality has been on the rise, despite al l the things we do, all the things we know, and all the resources we have.”

Using a research database from health services company Optum, Toth and colleagues conducted a retrospective longitudinal administrative claims analysis of long-term statin persistence among patients with PAD. Their assessment, which extended to 5 years, is unprecedented in study length for real-world statin adherence, Toth said.

The patient population included those at least 45 years old with diabetes and/or atherosclerotic cardiovascular disease with an index date and statin prescription filled in 2010. Investigators propensity-matched patients with triglyceride levels of at least 150 mg/dL to a comparator cohort with levels below 150 mg/dL and high-density lipoprotein cholesterol levels of more than 40 mg/dL (n= 23,181 each).

Among the 2 cohorts, mean patient age was 62.2 and 62.6 years, respectively; 49.7% and 49.5% were female, and mean follow-up was 41.4 and 42.5 months, respectively.

Investigators reported a statin adherence of ≤21% in patients with and without baseline PAD and/or elevated triglyceride at 5 years. In the years prior to year 5, adherence rates continually dropped—having started at about 60% in just year 1. Toth called the adherence rates “appalling.”

“The role of statins is highly established in reducing risk of cardiovascular events,” he explained. “It seems pretty fundamental that if you’re at high risk of events and have PAD, you’d want to adhere to statins to stay out of risk. We found that it couldn’t be less of the case.”

Toth also expressed frustration with the approximate 2% to 3% worsened rate of adherence observed in women, noting the commonly-held perception that female patients are more frequently in contact with prescribing physicians than men.

That said, many factors play into inadherence. Toth noted patients commonly misperceive statins as a harmful drug due to word-of-mouth and illegitimate information from “Dr. Google.” He disregarded the idea of drug costs, noting the 30-year-old therapy is even offered as a free, when-necessary prescription as part of local grocery store offers.

He advised that physicians better—and more frequently—address the significantly greater benefits to adhering to statins than the risks. Though other therapies carry similar rates of faltering adherence, statin prescription a regimen which should be discussed at every physician-patient appointment.

“These are life-saving drugs, hence why we need to take them lifelong,” Toth said.

The study, "Long-Term Statin Persistence Is Poor Among High-Risk Patients With Baseline Peripheral Artery Disease: A Real-World Administrative Claims Analysis of the Optum Research Database," was published online in JACC.