Factors Associated With PCSK9 Inhibitor Initiation Among US Veterans

Background Few adults at high risk for atherosclerotic cardiovascular disease events use a PCSK9i (proprotein convertase subtilisin/kexin type 9 inhibitor). Methods and Results Using data from the US Veterans Health Administration, we identified veterans who initiated a PCSK9i between January 2018 and December 2019, matched 1:4 to veterans who did not initiate this medication over this time period (case‐cohort study). Two cohorts of veterans were analyzed: (1) atherosclerotic cardiovascular disease, with a most recent low‐density lipoprotein cholesterol (LDL‐C) ≥70 mg/dL; and (2) severe hypercholesterolemia (ie, familial hypercholesterolemia or any prior LDL‐C ≥190 mg/dL, with most recent LDL‐C ≥100 mg/dL). Conditional logistic regression was used to analyze factors associated with PCSK9i initiation, adjusting for all factors, simultaneously. There were 2394 initiators and 9576 noninitiators in the atherosclerotic cardiovascular disease cohort (median LDL‐C, 141 and 96 mg/dL, respectively; P