Geography determines high-intensity statin use after MI

A study published in JAMA Cardiology July 24 suggests high-intensity statin use after MI depends on where patients live in the U.S., with 66% higher use in New England than in the country’s West South Central region.

In a retrospective analysis of 139,643 fee-for-service Medicare beneficiaries, Vera Bittner, MD, MSPH, of the University of Alabama and Birmingham, and colleagues studied Medicare claims and enrollment data to evaluate patients aged 66 and up who were hospitalized for a heart attack between Jan. 1, 2011, and June 30, 2015. All patients were prescribed statins within a month of their index admission.

High-intensity statin use is a class IA indication for MI victims who are 75 years or younger, the authors explained, with moderate-intensity therapy preferred for patients older than 75. Recent studies have found that, although the proportion of American adults taking statins has risen over the years, the therapy remains underused.

“For many years, regional variation in care processes and health outcomes across the United States have been documented for cardiovascular diseases and many other health conditions,” Bittner and co-authors wrote. “Between-facility variation in statin use has been found within hospital registries such as the Get with the Guidelines Registry, among Veterans Administration hospitals and in registries of clinical outpatient practices.”

The authors extracted beneficiary characteristics from Medicare data, hospital characteristics from the 2014 American Hospital Association Survey and defined nine regions of study according to the U.S. Census. High-intensity statins were considered 40-80 mg of atorvastatin calcium per day or 20-40 mg of rosuvastatin calcium each day; low- to moderate-intensity drugs were described as all other statin types and doses.

Bittner et al. found that high-intensity statin use increased between 2011 and 2015 among their pool of subjects, most of whom were in their seventies at the time of the study. Use increased from 23.4% in 2011 to 55.6% in 2015, but major treatment gaps were apparent across different regions.

New England saw 66% higher use of high-intensity statins following an MI compared to the U.S.’s West South Central region, according to the team’s findings. Patients were 15% more likely to receive a high-intensity prescription if they were admitted to a hospital with more than 500 beds; 11% more likely if the hospital was affiliated with a medical school; 10% more likely if they were men; and 35% more likely if they received a stent during their stay.

For-profit hospital ownership, patient age over 75 years, prior coronary disease and other comorbidities were linked to lower use of high-intensity statins.

In an editor’s note, Ann Marie Navar, MD, PhD, and Gregg C. Fonarow, MD, noted rates of high-intensity statin use varied nearly twofold from the poorest-performing region to the highest-performing region in the U.S. (41% and 73.5%, respectively), correlating with known geographic differences in CV mortality.

“Of the four states in the West South Central region, three were ranked in the top five for heart disease mortality in 2016,” Navar and Fonarow wrote.

They said a slew of socioeconomic factors likely feed into the disparities Bittner et al. discovered—factors that are “beyond the immediate control of physicians.” They include things like access to employment, health insurance, healthy food and affordable housing, but not use of high-intensity statins.

“High-intensity statins, including generic atorvastatin and rosuvastatin, are readily available at low cost at pharmacies across the United States,” the editors wrote. “Improvements in systems of care for patients seen in hospitals and outpatient care settings that underuse high-intensity statins in eligible patients with athersclerotic cardiovascular disease should be undertaken immediately to address this modifiable cause of geographic disparities in cardiovascular disease care quality and outcomes.”