Cardiac Tissue Characterization and the Diagnostic Value of Cardiovascular Magnetic Resonance in Systemic Connective Tissue Diseases

Abstract

Accurate diagnosis of cardiovascular involvement in connective tissue diseases (CTDs) remains challenging. We hypothesized that cardiovascular magnetic resonance (CMR) demonstrates cardiac lesions in symptomatic CTD patients with normal echocardiography. CMR from 246 CTD patients with typical cardiac symptoms (TCS; n = 146, group A) or atypical cardiac symptoms (ATCS; n = 100, group B) was retrospectively evaluated. Group A included 9 patients with inflammatory myopathy (IM), 35 with sarcoidosis, 30 with systemic sclerosis (SSc), 14 with systemic lupus erythematosus (SLE), 10 with rheumatoid arthritis (RA), and 48 with small vessel vasculitis. Group B included 25 patients with RA, 20 with SLE, 20 with sarcoidosis, 15 with SSc, 10 with IM, and 10 with small vessel vasculitis. CMR was performed by 1.5T; left ventricular ejection fraction, T2 ratio (edema imaging), and late gadolinium enhancement (LGE; fibrosis imaging) were evaluated. Acute and chronic lesions were characterized as LGE positive plus T2 ratio >2 and T2 ratio ≤2, respectively. According to LGE, lesions were characterized as diffuse subendocardial, subepicardial, and subendocardial/transmural due to vasculitis, myocarditis, and myocardial infarction, respectively. A stress study by dobutamine echocardiography or stress, nuclear, or adenosine CMR was performed in CTD patients with negative rest CMR. Abnormal CMR was identified in 32% (27% chronic) and 15% (12% chronic) of patients with TCS and ATCS, respectively. Lesions due to vasculitis, myocarditis, and myocardial infarction were evident in 27.4%, 62.6%, and 9.6% of CTD patients, respectively. Stress studies in CTD patients with negative CMR revealed coronary artery disease in 20%. CMR in symptomatic CTD patients with normal echocardiography can assess disease acuity and identify vasculitis, myocarditis, and myocardial infarction.