Comparison of RANKL expression, inflammatory markers, and cardiovascular risk in patients with acute coronary syndrome with and without rheumatoid arthritis

The mechanisms responsible for increased cardiovascular risk in patients with rheumatoid arthritis (RA) involve local and systemic inflammatory processes. We aimed to compare inflammatory markers and mortality risk in patients with acute coronary syndrome (ACS) with and without RA. The study involved 95 ACS patients (46 with RA and 49 without RA) and 40 healthy controls. Serum levels of Receptor Activator of Nuclear Factor Kappa B Ligand (sRANKL), Osteoprotegerin (sOPG), high-sensitivity C-reactive protein (hs-CRP) and high-sensitivity Tropinin I (hs-TnI) were tested in all participants. Additionally, ACS patients were assessed on RANKL expression (exRANKL) on coronary arteries and mortality risk on the Global Registry of Acute Coronary Events scale (GRACE). exRANKL was established in 35 (76%) ACS patients with RA, vs. 19 (39%) patients without RA, p < 0.001. RA patients had significantly higher levels of sRANKL and sOPG at 24 h and 48 h compared to ACS patients without RA and healthy controls (sRANKL 24 h: 121.33 vs. 51.67 vs. 36.94, p = 0.019; sRANKL 48 h: 89.21 vs. 36.95 vs. 36.94, p = 0.004; sOPG 24 h: 207.71 vs. 69.39 vs. 111.91, p < 0.001; sOPG 48 h: 143.36 vs. 69.38 vs. 111.91, p < 0.001). RA patients had significantly higher RANKL:OPG ratio at 48 h (0.062 vs. 0.53 vs. 0.33, p < 0.001), hs-CRP (28.82 vs. 23.67 vs. 2.60, p < 0.001) and hs-TnI (0.90 vs. 0.76 vs. 0.012). GRACE risk score was significantly higher in RA patients vs. those without RA (140.45 vs. 125.50, p = 0.030) and correlated with exRANKL, RANKL:OPG, hs-CRP, and hs-TnI. Our results indicate that exRANKL, inflammatory markers and mortality risk are amplified in ACS patients with RA compared to ACS patients without RA.