Determinants of myocardial fibrosis in patients with immune-mediated inflammatory diseases

Background

Myocardial fibrosis is an important adverse prognostic marker, however; determinants of myocardial fibrosis in immune-mediated inflammatory diseases (IMIDs) remain poorly defined.

Objectives

To identify determinants of myocardial fibrosis in patients with IMIDs, as measured by cardiovascular magnetic resonance (CMR) extracellular volume (ECV).

Methods

Cross-sectional study of 116 patients with IMIDs undergoing clinical CMR at Manchester University NHS Foundation Trust. CMR included pre- and post-contrast T1 mapping to measure myocardial ECV, with same day blood sampling. Determinants of ECV were investigated with univariable and multivariable linear regression.

Results

ECV varied significantly according to IMID diagnosis (ANOVA F statistic 2.80, P = 0.015); ECV was higher in patients with systemic sclerosis or scleroderma (SSc) compared to other IMIDs. Major determinants of ECV were SSc, smoking and body mass index (BMI); regression coefficients 3.33 (95% confidence interval 0.82 – 5.84), 3.08 (0.73 – 5.43), and -0.19 (-0.29 – -0.09) respectively, P < 0.01. Approximately a quarter of the variability in ECV could be explained by these predictors (optimism adjusted R2 0.265).

Conclusion

SSc is associated with a higher burden of myocardial fibrosis compared to other IMIDs. In patients with IMIDs, independent determinants of myocardial fibrosis were presence of SSc, smoking and BMI. Smoking and BMI are modifiable, thus lifestyle interventions could reduce myocardial fibrosis and improve cardiovascular outcomes.

Conflict of Interest

None