Study Details Effect of 2013 Guidelines on Statin Use, MACE Trends among US Adults

Chih-Lin Chi, PhD, MBA
Credit: University of Minnesota

Results of a new study underline the impact of the American College of Cardiology’s (ACC) and American Heart Association’s (AHA) 2013 guideline update on the cardiovascular risk and uptake of statin therapy among adults in the US.

An interrupted time series analysis of data from the Optum Labs Database Warehouse, results of the study suggest the release of the 2013 ACC/AHA Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults, which emphasized the role of higher-intensity statins to reduce atherosclerotic cardiovascular disease (ASCVD) risk, was associated with immediate improvement in optimal statin use in patients with ASCVD and improved 5-year major adverse cardiovascular event (MACE) survival for patient populations with ASCVD or diabetes.¹

“To the authors’ knowledge, no nationally representative studies have investigated the association of the 2013 ACC/AHA Guideline release with trend changes in MACE survival and other statin-related outcomes while controlling for the confounding effect from generic atorvastatin availability,” wrote investigators.¹

The efficacy and safety of statin therapies, combined with their generic status increasing affordability, statins have become one of the most widely used and impactful medications in the last century. Still, since the turn of the 21st century, optimized use of this decades-old class was still the subject of debate. In the 2013 ACC/AHA guidelines, the organization’s stance on statin therapy in patients with ASCVD underwent a significant shift away from targeting specific LDL-C targets to focusing on the most appropriate statin intensity given the ASCVD risk of a patient.^{1 ,2}

A team led by Chih-Lin Chi, PhD, MBA, a biomedical informatician at the Institute of Health Informatics at the University of Minnesota, and colleagues launched the current study with an interest in exploring the impact of this guidance on care in real-world settings. Of note, Chi and colleagues pointed out many previous studies have assessed the guidelines impact on statin prescription, but few had endeavored to understand the effect on MACE, which was the goal of their study.¹

With this in mind, the study was designed as a retrospective study of claims and electronic health records Optum Labs Database Warehouse, with the intent of assessing the association of the guideline’s release with the trend changes in 5-year MACE survival as well as statin use, optimal statin use, and statin adherence using interrupted time series analysis. Investigators pointed out their intent to control their analyses for generic atorvastatin availability, which they purport has been ignored in similar studies.¹

For inclusion int he study, patients needed to have met one of 4 benefit group cities in the 2013 guideline between 2002 and 2018, but had not started statin treatment. After limiting this cohort to those with index dates between December 2011 and May 2016 and those without 180 days or more of continuous enrollment after the index date, 197,021 patients were identified for inclusion. The statin benefit groups outlined in the guideline and included in the current study were defined as ASCVD, high-LDL, diabetes, and high ASCVD risk. Of the 197,021 patients included in the study, 19,060 had ASCVD, 33,907 had elevated LDL, 138,159 had diabetes, and 5895 had an elevated ASCVD risk.¹

Upon analysis, results indicated long-term trend of 5-year MACE Survival for the diabetes group improved significantly (P = .002) and trends were consistent over the evaluation window across all other groups. Assessments of outcomes of interest related to statin use revealed trend changes and statin adherence remained unchanged in all statin-benefit groups except for optimal statin use in the ASCVD, which experienced immediate improvement and long-term positive changes after the release (P <.001).¹

Investigators underlined several limitations within their study to consider. These included a relatively small sample size for the high-risk ASCVD group as a result of the availability of laboratory test results in the Optum database, the assumption trends were linear, optimal statin use and statin adherence were evaluated on statin initiators only, and reliance on diagnosis codes to determine cardiovascular death or sudden death.¹

“While our study evaluated the associations of the 2013 ACC/AHA Guideline with statin-related outcomes that may indicate the guideline’s potential impact, this study cannot infer the causal effect of the guideline,” investigators wrote.¹ “Observed changes in outcome trends could be partially attributable to changes in the underlying risk profile of the study population; how to disentangle such systematic changes from the effects of the guidelines and generic statin availability requires further investigation.”

References:

1. _{^{Yew PY, Loth M, Adam TJ, et al. Potential impact of blood cholesterol guidelines on statin treatment in the U.S. population using interrupted time series analysis. BMC Cardiovasc Disord. 2024;24(1):245. Published 2024 May 10. doi:10.1186/s12872-024-03921-z}}
2. _{^{Stone NJ, Robinson JG, Lichtenstein AH, et al. 2013 ACC/AHA guideline on the treatment of blood cholesterol to reduce atherosclerotic cardiovascular risk in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines [published correction appears in J Am Coll Cardiol. 2014 Jul 1;63(25 Pt B):3024-3025] [published correction appears in J Am Coll Cardiol. 2015 Dec 22;66(24):2812]. J Am Coll Cardiol. 2014;63(25 Pt B):2889-2934. doi:10.1016/j.jacc.2013.11.002}}