This prospective longitudinal study evaluated how hydroxychloroquine (HCQ) blood levels and long-term intake (measured by proportion of days covered, PDC) relate to 10-year ASCVD risk at baseline and after 1 year in 248 adults with SLE from the Wisconsin cohort.
Patients with very low HCQ blood levels (<200 ng/mL) AND low long-term intake (PDC <80%) had significantly higher baseline ASCVD risk (+2.1%, mean 6.6%). Those who stayed in or moved into low-exposure categories had the highest follow-up ASCVD risk (5.7%).
Single-center cohort (Wisconsin) limits generalizability; ASCVD risk was estimated using the PREVENT calculator rather than measured hard outcomes; 1-year follow-up is short for a cardiovascular endpoint study.
Monitor whole-blood HCQ levels and adherence (PDC) in SLE patients — those with levels <200 ng/mL and PDC <80% carry meaningfully higher cardiovascular risk. Supporting sustained HCQ adherence may reduce ASCVD risk and limit the need for additional preventive therapies.
