Myocardial extracellular volume fraction by cardiac magnetic resonance for early detection of left ventricular involvement in systemic sclerosis

Abstract

Background: Systemic sclerosis (SSc) is associated with progressive myocardial fibrosis leading to impaired function. Cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) poorly detects early interstitial diffuse fibrosis, but CMR T1-mapping can quantify extracellular volume fraction (EVF,%) which is dependent upon the collagen content in the myocardium. We sought to detect left ventricular (LV) structural abnormalities using EVF quantification in SSc patients. Methods: 16 controls and 33 SSc patients without resting pulmonary hypertension and normal LGE-CMR were prospectively enrolled in the study and underwent both CMR with T1-mapping for EVF quantification and circumferential strain assessment and echocardiography exam for LV diastolic function evaluation. Results: SSc patients had a significantly higher global EVF than controls (30.0 (28.0-31.9) vs 26,8 (25,4-29,1)%, P<0.01). Of note, EVF was found higher within the basal and mid-ventricular LV segments than in the apical segments (P<0.01). SSc patients had also larger left atrial volume (44 (38-55) vs 29 (23-38) mL/m2, p<0.01) and lower circumferential strain (-18.3 vs -20,2%, p<0.05) than controls. Moreover, global EVF correlated with the severity of diastolic dysfunction (Figure 1). ![Figure][1] Figure 1. EVF according to diastolic dysfunction Conclusion: In SSc patients, CMR T1-mapping shows an increased EVF which might be indicative of diffuse interstitial myocardial fibrosis associated with diastolic LV dysfunction. [1]: pending:yes