Myasthenia Gravis Outcomes After Use of Statins and Other Contraindicated Treatments: Results From the French National Insurance Database.

BACKGROUND

Clinical guidelines for treating myasthenia gravis (MG) recommend avoiding certain therapies because of a risk of exacerbating MG. We evaluated use of statins and other classically contraindicated therapies and their impact on healthcare outcomes among patients with MG in France.

METHODS

This was an observational, retrospective, longitudinal cohort study using data from the French national health insurance database. Adult patients with MG-related claims from 2013 to 2020 were included. The first MG claim date was the index date, with follow-up until end-of-study or death. Multivariable regression models evaluated the risk of intensive care unit (ICU) admission for MG or death during periods of exposure versus nonexposure to contraindicated treatments.

RESULTS

Of 14,459 individuals with MG, 12,954 (89.6%) received a contraindicated treatment during follow-up, and 4160 (28.8%) received statins. In multivariable regression analyses, exposure to any contraindicated treatment was not significantly associated with risk of ICU admission for MG (hazard ratio [HR] 1.038; 95% confidence interval [CI] 0.968-1.113; p = not significant) but was associated with significantly higher risk of death (HR 1.167; 95% CI 1.075-1.266; p < 0.001) versus nonexposure. In contrast, statins were associated with a greater risk of ICU admission (HR 1.133; 95% CI 1.065-1.205; p < 0.001) but lower risk of death (HR 0.626; 95% CI 0.565-0.694; p < 0.001).

CONCLUSION

This large, real-world study suggests that for some contraindicated medications, including statins, longer-term mortality benefits are likely to outweigh short-term risks of exacerbating MG.