The aim of our pilot study was to prospectively evaluate the effect of inhibiting interleukin 6 on the left ventricular (LV) structure and function in patients with rheumatoid arthritis (RA) without cardiac symptoms, using cardiac magnetic resonance (CMR).
Female patients with RA with active disease and healthy controls were enrolled. Cardiac symptoms were absent in all subjects. Tocilizumab (TCZ; 8 mg/kg IV every 4 weeks) was prescribed for patients with RA with an inadequate clinical response to methotrexate. All subjects underwent baseline evaluation of LV function and structure measured by CMR. We compared measures of LV geometry and function between patients with RA and patients without RA controls at baseline, and changes in the same variables between baseline and after 52 weeks of treatment among the group with RA.
Twenty women with RA were compared with 20 women without RA of similar mean age. In patients with RA at baseline, ejection fraction (EF) was significantly lower (-3.7%) and LV mass index (LVMI) significantly higher (+9.2%) compared with controls. TCZ treatment resulted in a significant decrease in the Simplified Disease Activity Index (SDAI) after 52 weeks of treatment, paralleling a significant increase in EF (+8.2%) and a significant decrease in LVMI (-24.4%) over the same period. The percentage change in LVMI correlated strongly with the percentage change in SDAI (r = -0.63, p = 0.0028). LV geometry in the group with RA at baseline showed eccentric hyper-trophy compared with the group without RA, a condition that normalized after TCZ treatment.
TCZ treatment significantly increased EF and decreased LVMI associated with disease activity.