Early diagnosis of cardiac involvement in idiopathic inflammatory myopathy by cardiac magnetic resonance tomography.

The aim of this study was to investigate cardiac involvement in patients with idiopathic inflammatory myopathies excluding inclusion body myositis with cardiac magnetic resonance tomography (CMR). A case series of 53 patients with polymyositis, dermatomyositis, or non-specific myositis underwent CMR including functional imaging, T1-weighted, and late gadolinium enhancement (LGE) imaging. T1-weighted and LGE images were analyzed for myocardial enhancement. Reduced left ventricular function (LVF) was found in 9 (7%) patients. Patients with reduced LVF more often presented with early and late myocardial enhancement (p = 0.014 and p = 0.001). In 33 (62.3%) patients, LGE was observed by CMR. These patients had significantly lower left ventricular ejection fractions (p < 0.001) compared to patients without LGE. LGE was mainly present in the lateral (p < 0.01) and inferior (p < 0.02) segments. No correlations of LGE presence or reduced LVF to cardiovascular risk factors were found. Myocardial inflammation is very frequent in polymyositis, dermatomyositis, and non-specific myositis. In our patient, cohort CMR demonstrated signs of myocardial inflammation in 62.3%. CMR seems to offer a measurable and quantifiable diagnostic tool for cardiac involvement of idiopathic inflammatory myopathies and can thus be used to monitor disease progress and therapeutic success in these patients.