Early cardiac involvement detected by cardiac magnetic resonance feature tracking in idiopathic inflammatory myopathy with preserved ejection fraction.

Cardiac involvement is common in idiopathic inflammatory myopathy (IIM) but often subclinical. Cardiac magnetic resonance (CMR) is a promising tool in detecting cardiac involvement in patients with IIM. The aim of this study was to assess cardiac involvement in IIM patients by CMR feature tracking (CMR-FT). Thirty-seven IIM patients and 25 controls were enrolled in this retrospective study. The left ventricular (LV) functional parameters such as volume and ejection fraction were measured. Global and regional LV peak strain (PS) in radial, circumferential and longitudinal directions were derived from cine images. Left atrial (LA) volume, longitudinal strain and strain rate (SR) parameters and LA reservoir function, conduit function and booster pump function were assessed, respectively. IIM patients with preserved LVEF showed significantly reduced global and regional LV PS in longitudinal direction (all p < 0.05). Compared with controls, LA reservoir and conduit function were significantly impaired in IIM patients (all p < 0.05). The global LV longitudinal PS, LAVpre-ac and SRe were independent predictors of IIM. By Pearson's correlation analysis, the LV global radial, circumferential and longitudinal PS were all correlated to LVEF in IIM patients (r = 0.526, p < 0.001 vs. r = - 0.514, p < 0.001 vs. r = - 0.288, p = 0.023). CMR-FT based LV and LA deformation performance could early detect cardiac involvement in IIM patients with preserved LVEF.