Both low long-term hydroxychloroquine (HCQ) intake and very low HCQ blood levels increase 10-year atherosclerotic cardiovascular disease (ASCVD) risk in patients with systemic lupus erythematosus (SLE), according to study results published in Arthritis Care & Research.
Mean 10-year PREVENT ASCVD risk was 3.3%±4.2%.
Patients with both very low HCQ levels (<200 ng/mL) and low long-term intake (proportion of days covered, <80%) had a 2.1% higher risk predicted ASCVD risk at baseline vs those with therapeutic HCQ levels and 100% proportion of days covered.
This group also had the highest predicted 10-year ASCVD risk at baseline (6.6%), indicative of borderline-intermediate ASCVD risk.
At 1 year, patients with lower HCQ blood levels and lower long-term intake, or who persistently maintained very low levels and low intake, had the highest predicted ASCVD risk (5.7%).
Both low long-term hydroxychloroquine (HCQ) intake and very low HCQ blood levels increase 10-year atherosclerotic cardiovascular disease (ASCVD) risk in patients with systemic lupus erythematosus (SLE), according to study results published in Arthritis Care & Research.
In a prospective longitudinal study of patients with established SLE receiving HCQ, researchers sought to evaluate how changes in HCQ blood levels and long-term intake predicted ASCVD risk at study baseline and 1-year follow-up.
The study cohort included 248 adults with SLE (mean age, 47±17 years; 90% women). At baseline, median HCQ blood level was 786 ng/mL (IQR, 510–1,120), median HCQ dose was 4.3 mg/kg/day (IQR, 3.6–4.9), and mean proportion of days covered was 87%±25%. Mean 10-year PREVENT ASCVD risk was 3.3%±4.2%. Within the cohort, 6.5% had very low HCQ levels (<200 ng/mL) with a mean proportion of days covered of 66%; 114 patients had HCQ blood levels greater than 750 ng/mL with a mean proportion of days covered of 100%.
Patients with both very low HCQ levels (<200 ng/mL) and low long-term intake (proportion of days covered, <80%) had a 2.1% higher risk predicted ASCVD risk at baseline vs those with therapeutic HCQ levels and 100% proportion of days covered. This group also had the highest predicted 10-year ASCVD risk at baseline (6.6%), indicative of borderline-intermediate ASCVD risk.
Future multicenter studies are warranted to validate these results and to develop and test interventions targeting this longitudinal interaction in SLE.
Conversely, very low HCQ levels accompanied by a high proportion of days covered were not significantly associated with increased ASCVD risk (mean difference, −0.62%), highlighting the importance of considering both measures of HCQ exposure.
At 1 year, patients with lower HCQ blood levels and lower long-term intake, or who persistently maintained very low levels and low intake, had the highest predicted ASCVD risk (5.7%). All other HCQ exposure and intake categories had predicted mean ASCVD risks of less than 5%.
Study limitations include the 1-year follow-up, which may be insufficient to capture longer-term changes in adherence and ASCVD risk; high baseline HCQ adherence and the small number of patients in the highest-risk category (n=7), which limit generalizability and statistical precision; and potential underestimation of ASCVD risk because some patients were receiving statins and high-risk antiphospholipid antibody profiles were unavailable.
“Future multicenter studies are warranted to validate these results and to develop and test interventions targeting this longitudinal interaction in SLE and potential clinical significance and impact on clinical practice and health outcomes in SLE,” the researchers concluded.
