Pulmonary fibrosis in systemic sclerosis: association with myocardial fibrosis

To evaluate the relationship between pulmonary and myocardial fibrosis in patients with systemic sclerosis (SS).

Eighteen patients with SS prospectively underwent cardiac magnetic resonance imaging (CMR) and high-resolution computed tomography (HRCT) of the chest. Cardiac biomarkers (N-terminal pro B-type natriuretic peptide) and quality-of-life measures (SF-36 and SS health assessment questionnaires) were assessed. Two readers blinded to other test results evaluated the CMRs in consensus for functional left and right ventricular parameters and for myocardial late enhancement. HRCT images were reviewed at 5 levels and scored for total disease extent, extent of reticulation, proportion of ground-glass opacities (GGO), and coarseness of reticulation.

Right ventricular ejection fraction correlated significantly with the percentage of late enhancement of the myocardium (R=0.63, P<0.01), extent of pulmonary fibrosis (R=0.57, P<0.01), and extent of GGO (R=0.53, P<0.05). Significant correlations were also found between the percentage of late enhancement of the myocardium and the extent of overall pulmonary fibrosis (R=0.59, P<0.05) and the extent of the ground-glass subcomponent (R=0.58, P<0.05). N-terminal pro B-type natriuretic peptide correlated significantly with the number of myocardial segments with late enhancement (R=0.64, P<0.05). Stepwise multiple linear regression revealed the extent of pulmonary GGO to be the only independent predictor of the percentage of myocardial enhancement (R2=0.61, P<0.0001).

In patients with SS with pulmonary fibrosis on HRCT images, CMR may be a useful test to detect early-stage myocardial fibrosis.