Assessment of myocardial deformation with cardiac magnetic resonance strain imaging improves risk stratification in patients with dilated cardiomyopathy.

Abstract

To investigate the prognostic impact of left-ventricular (LV) cardiac magnetic resonance (CMR) deformation imaging in patients with non-ischaemic dilated cardiomyopathy (DCM) compared with late-gadolinium enhancement (LGE) quantification and LV ejection fraction (EF). A total of 210 subjects with DCM were examined prospectively with standard CMR including measurement of LGE for quantification of myocardial fibrosis and feature tracking strain imaging for assessment of LV deformation. The predefined primary endpoint, a combination of cardiac death, heart transplantation, and aborted sudden cardiac death, occurred in 26 subjects during the median follow-up period of 5.3 years. LV radial, circumferential, and longitudinal strains were significantly associated with outcome. Using separate multivariate analysis models, global longitudinal strain (average of peak negative strain values) and mean longitudinal strain (negative peak of the mean curve of all segments) were independent prognostic parameters surpassing the value of global and mean LV radial and circumferential strain, as well as NT-proBNP, EF, and LGE mass. A global longitudinal strain greater than -12.5% predicted outcome even in patients with EF < 35% (P < 0.01) and in those with presence of LGE (P < 0.001). Mean longitudinal strain was further investigated using a clinical model with predefined cut-offs (EF < 35%, presence of LGE, NYHA class, mean longitudinal strain greater than -10%). Mean longitudinal strain exhibited an independent prognostic value surpassing that provided by NYHA, EF, and LGE (HR = 5.4, P < 0.01). LV longitudinal strain assessed with CMR is an independent predictor of survival in DCM and offers incremental information for risk stratification beyond clinical parameters, biomarker, and standard CMR.