Background/Purpose: Rheumatic diseases such as autoimmune myopathy (AIM), systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA) confer an increased risk for atherosclerotic disease. The 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) inhibitors, or statins, play an important role in cardiovascular (CV) protection. However, concerns for muscle-related adverse effects may deter statin use in patients with AIM.
 
We evaluated the prevalence of statin use in patients with AIM and a statin-indicated condition and compared it to patients with SLE, RA, and noninflammatory conditions followed at a single centre.

Methods: We conducted an electronic chart review of patients seen between January 2016 and June 2023 at The Arthritis Centre (TAC) in Winnipeg, the primary rheumatology referral centre for Manitoba, Canada. Patients diagnosed by a rheumatologist with an AIM and ≥1 statin-indicated condition as per the 2021 Canadian Cardiovascular Society Guidelines were included. Those with necrotising autoimmune myositis (NAM) associated with statin use or anti-HMGCR antibodies were excluded. Age and sex-matched comparator groups were identified at a 1:1 ratio for SLE, RA, and non-inflammatory conditions (predominantly osteoarthritis). Categorical group differences were analyzed by chi-square test. Multivariable regression models were constructed to assess whether these conditions and other clinical factors are associated with current statin use (prescription fill within 4 months of last follow-up in the provincial prescription database).

Results: Of the 201 patients with AIM followed at TAC, 40 met study criteria: 62% female, mean age 68+/-11 (range 41-86) years. Statin indication reflected secondary prevention (e.g. coronary artery disease) in 19 of the AIM patients versus 14 of the non-inflammatory group. Only 40% (16/40) with AIM were on a statin (additional 3 on alternative lipid-lowering agent) compared with 70% (28/40) of the non-inflammatory group (p = 0.007). Compared to the noninflammatory group, the odds of current statin use was significantly lower in patients with AIM [adjusted OR 0.27 (95% Confidence Interval 0.10-0.68)] and SLE [0.28 (0.10-0.69)], but not RA [0.56 (0.22-1.41)], whereas age, sex, and number of statin-indicated conditions (1 vs. >1) were not associated with statin use. Within the AIM cohort, serum CK, disease duration (≤3 vs. >3y), DMARD use, prednisone use, and concurrent cancer were not significantly associated with statin use.

Conclusion: Despite a clinical indication, statin use was significantly lower among patients with AIM and SLE versus non-inflammatory conditions. Future studies should evaluate other deterrents to statin use in these high CV risk populations including comorbidities, pill burden, and primary care access.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/reduced-statin-use-in-patients-with-autoimmune-myopathies-and-systemic-lupus-erythematosus-compared-to-rheumatoid-arthritis-and-non-inflammatory-diseases/