Rare Disease: Cardiac Risk Assessment With MRI in Patients With Myotonic Dystrophy Type 1

Abstract

Introduction: To evaluate myocardial strain and extracellular volume in myotonic dystrophy type 1 (DM1) patients as potential imaging biomarkers of subclinical cardiac pathology. Materials and methods:We retrospectively analyzed 9 DM1 patients without apparent cardiac disease who had undergone cardiac magnetic resonance at our center. Patients were age-and sex-matched with healthy controls. The Mann-Whitney U test was used to compare cardiac strain between the two groups. The t-test was used to compare the extracellular volume obtained in DM1 patients with that in healthy subject. Spearman's ρ was used for studying the associations among imaging parameters.Results: Global cardiac strain (median −19.1%; IQR −20.5%, −16.5%) in DM1 patients was lower (p = 0.011) than that in controls (median−21.7%; IQR−22.7%,-21.3%). Global extracellular volume in DM1 patients (median 32.3%; IQR 29.3%,36.8%) was significantly (p = 0.008) higher than that reported in literature in healthy subjects (median 25.6%; IQR 19.9%,31.9%). Global cardiac strain showed a strong, positive correlation with septal strain (ρ = 0.767, p = 0.016) and with both global (ρ = 0.733 p = 0.025) and septal extracellular volume (ρ = 0.767, p = 0.016). Discussion:The increase in cardiac extracellular volume and decrease in strain are signs of early cardiac pathology in DM1. Physicians dealing with DM1 may take into consideration cardiac magnetic resonance as a screening tool to identify early cardiac involvement in this condition.

Cardiac Pathology in Myotonic Dystrophy Type 1

“…Luetkens et al studied a cohort of DM1 patients without known cardiovascular disease and found CMR evidence of diffuse fibrosis (i.e., increased T1 and ECV values; patchy and extensive increased LGE uptake) in about 35–40% of patients, decreased LV-ejection fraction, and decreased myocardial strain measurements [ 91 ]. Similar findings of increased ECV and decreased cardiac strain were reported in a smaller cohort of DM1 patients without evidence of cardiac disease [ 87 ].…”

“…The last decade has seen multiple studies documenting cardiac magnetic resonance imaging (CMR) changes in the heart of individuals with DM1. Many investigators commented on the frequency of cardiac fibrosis and the possibility that CMR could be a valuable biomarker for DM1 [ 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 ]. CMR can be used to assess the structural and functional parameters seen by echocardiography, and in addition, it provides a means for assessing fatty infiltration, edema and diffuse and focal fibrosis.…”

Prognostic Utility of Cardiovascular Magnetic Resonance–Based Phenotyping in Patients With Muscular Dystrophy

“… 17 , 23 , 24 Several studies have examined the role of myocardial strain in patients with MD. 25 , 26 , 27 , 28 , 29 Of particular relevance, a recent study also applied a 3D strain analysis technique to study conventional, geometry‐dependent measures in 111 patients with a broad range of neuromuscular diseases inclusive of, but not limited, to MD. 29 Similar to our study, they observed both 3D‐GCS and 3D‐GRS are associated with the presence of replacement fibrosis.…”

Cardiac magnetic resonance findings and prognosis in type 1 myotonic dystrophy

“…Mid-wall late gadolinium enhancement (LGE) has been reported, most often in the septal/ inferolateral segments, 16,18,[26][27][28][29][30][31] and an enlarged extracellular volume has been demonstrated through mapping techniques. 16,17,28,30,32 The link between CMR findings and electrical disturbances in DM1 is controversial [16][17][18][27][28][29][30][31][32][33][34] and their prognostic significance is unclear.…”