Factors associated with lipid lowering therapy in the multi-ethnic study of atherosclerosis

Background: Lipid-lowering therapy (LLT) plays a central role in managing atherosclerotic cardiovascular disease (ASCVD) risk, but its underuse is reported in over 40% of the qualified population in the United States. Studies on factors, particularly actionable factors associated with guideline-directed LLT are limited. Methods: This study evaluated participants from the Multi-Ethnic Study of Atherosclerosis (MESA) on their qualification for LLT at exam 5 (2010–2012) according to the 2013 American College of Cardiology (ACC)/American Heart Association (AHA) guideline on cholesterol management. Participants were categorized as on-LLT or off-LLT at the following exam (2016–2018). Multi-variable relative risk (RR) models were used to analyze between LLT usage and factors prior to 2013, including age, gender, race/ethnicity, education level and medical insurance, income, smoking, body mass index (BMI), diabetes, hypertension, and presence of coronary artery calcium (CAC). Results: Among the 2114 participants qualified for LLT at exam 5 with an average age of 70.7, 1,129 (53.4%) were on LLT while 985 (46.6%) were off LLT at exam 6. Black participants were less likely to be on LLT compared to the reference white participants (RR 0.80, 95% confidence interval CI 0.71–0.90). Higher BMI showed borderline significant association with LLT. Comorbidities of diabetes and hypertension were positively associated with LLT use (RR 1.39 and 1.23, 95% CI 1.27–1.52 and 1.10–1.36, respectively). CAC score > 0 as an indicator of subclinical ASCVD was strongly associated with LLT too, independent of other demographic or comorbidity factors (RR 1.38, 95% CI 1.21–1.56). Conclusions: This study identifies key factors influencing LLT use among MESA participants. Black participants were less likely to be on LLT, highlighting healthcare disparities. CAC presence was strongly associated with LLT use, suggesting that CAC measurement could be an actionable factor to improve adherence to LLT guidelines.