Systemic sclerosis medications and risk of scleroderma renal crisis

Background: Scleroderma Renal Crisis (SRC) is associated with significant morbidity and mortality. While prednisone is strongly associated with SRC, there are no previous large cohort studies that have evaluated ace inhibitor (ACEi) calcium channel blocker (CCB), angiotensin receptor blocker (ARB), endothelin receptor blocker (ERB), non-steroidal anti-inflammatory drug (NSAID), fluticasone, or mycophenolate mofetil (MMF) use in systemic sclerosis (SSc) and the risk of SRC. Methods: In this retrospective cohort study of the entire military electronic medical record between 2005 and 2016, we compared the use of ACEi, ARB, CCB, NSAID, ERB, fluticasone, and MMF after SSc diagnosis for 31 cases who subsequently developed SRC to 322 SSc without SRC disease controls. Results: ACEi was associated with an increased risk for SRC adjusted for age, race, and prednisone use [odds ratio (OR) 4.1, 95% confidence interval (CI) 1.6-10.2, P = 0.003]. On stratified analyses, ACEi was only associated with SRC in the presence [OR 5.3, 95% CI 1.1-29.2, p = 0.03], and not the absence of proteinuria. In addition, a doubling of ACEi dose [61% vs. 12%, p < 0.001) and achieving maximum ACEi dose [45% vs. 4%, p < 0.001] after SSc diagnosis was associated with future SRC. CCB, ARB, NSAIDs, ERB, fluticasone, and MMF use were not significantly associated with SRC. Conclusion: ACEi use at SSC diagnosis was associated with an increased risk for SRC. Results suggest that it may be a passive marker of known SRC risk factors, such as proteinuria, or evolving disease. SSC patients that require ACEi should be more closely monitored for SRC.