Prescribing Patterns of Evolocumab and Alirocumab in Patients With Familial Hypercholesterolemia: A Cross-Sectional Study Using the National Ambulatory Medical Care Survey, 2018–2019

BACKGROUND: Familial hypercholesterolemia (FH) is a hereditary lipid disorder that substantially elevates cardiovascular risk. Despite strong evidence and guideline recommendations, the real-world use of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors in FH remains uncertain. OBJECTIVE: This study aimed to evaluate national trends in PCSK9 inhibitor prescribing during ambulatory visits for adults with FH in the United States from 2018 to 2019. METHODS: Revision, Clinical Modification (ICD-10-CM) code E78.0). The primary outcome was prescription of a PCSK9 inhibitor (evolocumab or alirocumab), identified through medication codes. Patient demographics, insurance type, and physician specialty were examined. Survey weights were applied to generate national estimates, and logistic regression was used to explore the association between age and prescribing. RESULTS: Among the weighted total of 20,414,210 visits for adults with FH, only 69,672 visits (0.3%) included a prescription for a PCSK9 inhibitor. Prescribing was observed exclusively among female, White patients and occurred almost entirely in primary care settings. Patients receiving PCSK9 therapy were older than those not prescribed (mean 71.0 vs. 66.5 years, p=0.004). No prescribing was observed among males, racial/ethnic minority groups, or patients seen in surgical or medical specialties. In survey-weighted logistic regression, each additional year of age was associated with a 4% higher odds of PCSK9 prescribing (OR 1.04, 95% CI: 1.02-1.07, p=0.002). CONCLUSION: PCSK9 inhibitor use in FH patients during U.S. ambulatory visits was rare, highlighting a persistent gap between evidence-based guidelines and clinical practice. Broader adoption strategies are needed to optimize lipid management and reduce cardiovascular risk in FH.