Circumferential Strain Analysis Identifies Strata of Cardiomyopathy in Duchenne Muscular Dystrophy

Abstract

Objectives This study sought to evaluate the natural history of occult cardiac dysfunction in Duchenne Muscular Dystrophy (DMD). Background DMD is characterized by progressive cardiac dysfunction and myocardial fibrosis late in the disease process. We hypothesized that left ventricular myocardial peak circumferential strain (εcc) would decrease in DMD prior to global systolic functional abnormalities regardless of age or ventricular ejection fraction (EF). Methods We evaluated cardiac magnetic resonance image (CMR) data from 70 DMD patients and 16 aged-matched control subjects. Standard imaging data included steady-state free precession (SSFP) short-axis cine stack images, cine myocardial tagged images and myocardial delayed enhancement (MDE, an indicator of myocardial fibrosis) sequences. Analysis was performed using QMASS® and HARP® softwares. DMD patient data was subdivided by age (< 10 years or > 10 years), EF (> 55% or <55%) and the presence or absence of MDE. Results DMD patients with normal EF had reduced εcc at an early age (<10 years) compared to control subjects (p< 0.01). DMD patients >10 years with normal EF had further decline in εcc compared to younger DMD patients (p<0.01). There was further decline in εcc with age in patients with reduced EF (p<0.01) without MDE. The oldest patients, with both reduced EF and positive MDE, exhibited the lowest εcc. None of the patients had ventricular hypertrophy. Conclusions Myocardial strain abnormalities are prevalent in young DMD patients despite normal EF, and these strain values continue to decline with advancing age. Strain analysis in combination with standard CMR and MDE imaging provides a means to stratify DMD cardiomyopathy.

Occult Cardiotoxicity in Childhood Cancer Survivors Exposed to Anthracycline Therapy

“…32 The presence of myocardial strain abnormalities, as well as a serial decline in myocardial strain magnitude without a change in ejection fraction, has been previously reported in other forms of nonischemic cardiomyopathy. 14,[33][34][35] Our data provide evidence of similar findings in AIC subjects with reductions in regional performance in these subjects as demonstrated by low peak longitudinal (ε ιι ) and circumferential strain (ε cc ) magnitude in all segments of the myocardium. In contrast to the widespread segmental involvement demonstrated by CMR, speckle-tracking techniques by TTE demonstrated reductions limited to the anteroseptal and inferoseptal segments.…”

Magnetic Resonance Imaging of Myocardial Deformation and Scarring in Coronary Artery Disease.

“…In this study, 100% of the SSFP images were of good quality, which is similar to previous studies in which 95% of the scans were of high quali-ty [150]. Those studies used a single mid-ventricular slice, which might have concealed low image quality at the base and the apex, as has been shown for tagging [151,152]. The effects of reduced image quality at the basal and apical levels might have contributed to the failure of HARP analysis in 8% of the patients.…”

“…It was shown previously that strain from HARP has a relatively low reproducibility in the basal and apical regions [151,152]. That problem could be related to partial volume effects, especially exaggerated displacement in the radial direction in apical segments and in the longitudinal direction in basal segments.…”

Cardiac Management of Ventilator-Assisted Individuals with Duchenne Muscular Dystrophy

“…However, despite the clinical challenges, CMR imaging has been shown to be sensitive for early findings of cardiac disease prior to systolic dysfunction including reduced myocardial circumferential strain and areas of fibrosis identified with the use of late gadolinium enhancement. [26][27][28] CMR has also been used to characterize the pattern of remodelling and changes in LV geometry that occur with cardiac disease in DMD as a unique process not fully explained by the traditional thinking of progressive dilated cardiomyopathy. 29 CMR is not currently included in clinical guidelines for DMD, but it is a promising area of research to further understand the development and progression of cardiac disease in this population.…”