Abstract
BACKGROUND: Cardiovascular magnetic resonance (CMR) imaging with contrast enhancement (CE) of the coronary artery wall has been proven effective for detecting coronary involvement in IgG4-related disease (IgG4-RD). This study seeks to further investigate the value of coronary wall CE on CMR in assessing treatment response. METHODS: We prospectively enrolled 30 IgG4-RD patients with coronary involvement and conducted follow-up evaluations. All participants underwent coronary wall imaging with CMR, both before and after treatment with a combination of glucocorticoids and steroid-sparing immunosuppression. Concurrently, inflammatory-related laboratory markers and IgG4-RD Responder Index (RI) scores were collected and analyzed. RESULTS: Most patients (87% [26/30]) exhibited a significant monthly reduction in total coronary wall CE area (ΔCE area/months = 0.32 [interquartile range (IQR): 0.03-0.88] cm²/month) and contrast-to-noise ratio (CNR) (ΔCNR/months = 0.09 [IQR: 0.01-0.41]/month). Both parameters were positively correlated with monthly changes in inflammatory markers, including ΔIgG4/months (r = 0.366 and 0.388, respectively), Δ erythrocyte sedimentation rate/months (r = 0.617 and 0.539), ΔIgG/months (r = 0.565 and 0.578), and ΔIgE/months (r = 0.512 and 0.499) (all P < 0.05). In the "heart/pericardium" organ-specific domain of the IgG4-RD RI, the rate of change in the modified index (RI') incorporating coronary wall CE was significantly greater than that of the standard RI (ΔRI'/months vs ΔRI/months: 0.1 vs 0, P = 0.006). Similarly, in the overall multi-organ assessment, ΔRI'/months showed a significant improvement over ΔRI/months (0.68 vs 0.67, P = 0.006). Moreover, ΔCE area/months correlated positively with both ΔRI/months (r = 0.627, P < 0.001) and ΔRI'/months (r = 0.683, P < 0.001). ΔCNR/months also correlated positively with ΔRI/months (r = 0.500, P = 0.005) and ΔRI'/months (r = 0.548, P = 0.002). CONCLUSION: Glucocorticoid combined with steroid-sparing immunosuppression therapy is effective in treating IgG4-RD with coronary involvement. Coronary wall CE on CMR emerges as a valuable imaging biomarker that complements serological markers in assessing treatment response. Incorporating coronary wall CE enhances RI scoring, aiding therapeutic decisions and disease monitoring.