The impact of HCQ blood levels and intake on ASCVD risk in SLE

Results from a prospective, longitudinal cohort study assessing the impact of hydroxychloroquine (HCQ) blood levels and long-term HCQ intake on atherosclerotic cardiovascular disease (ASCVD) risk in 248 patients with systemic lupus erythematosus (SLE) were published in Arthritis Care & Research by Garg et al.  

Key data: In a multivariable model, patients with HCQ blood levels <200 ng/mL and low long-term HCQ intake (proportion of days covered [PDC] <80%) had a 2.18% higher baseline ASCVD risk (95% confidence interval [CI], 0.26–4.11; p = 0.027) vs those with therapeutic HCQ levels ≥750 ng/mL and high long-term intake (PDC ≥80%). The greatest predicted risk of ASCVD was in patients with HCQ blood levels <200 ng/mL and PDC <80% (6.6%), while risk was lowest in patients with HCQ blood levels within 200–749 ng/mL and PDC <80% (3.0%). At 1-year follow-up, patients who transitioned to or remained in low-exposure categories had the highest predicted mean ASCVD risk (5.7%). 

Key learning: Low exposure to HCQ increased the risk of ASCVD in patients with SLE, highlighting the importance of monitoring long-term HCQ intake and achieving therapeutic blood levels (≥750 ng/mL) to reduce cardiovascular risk.