Global, segmental and layer specific analysis of myocardial involvement in Duchenne muscular dystrophy by cardiovascular magnetic resonance native T1 mapping

Association Between Myocardial Oxygenation and Fibrosis in Duchenne Muscular Dystrophy: Analysis by Rest Oxygenation-Sensitive Magnetic Resonance Imaging

BACKGROUND

Myocardial hypoxia has been demonstrated in many cardiomyopathies and is related to development of myocardial fibrosis. However, myocardial hypoxia and its association with myocardial fibrosis are understudied in Duchenne muscular dystrophy (DMD)-associated cardiomyopathy.

PURPOSE

To evaluate myocardial hypoxia by oxygenation-sensitive (OS) cardiac magnetic resonance imaging, and further explore its association with fibrosis.

STUDY TYPE

Prospective.

SUBJECTS

Ninety-one DMD boys (8.78 ± 2.32) and 30 healthy boys (9.07 ± 2.30).

FIELD STRENGTH/SEQUENCE

3 T, Balanced steady-state free procession, Modified Look-Locker inversion recovery sequence and Single-shot phase-sensitive inversion recovery sequence.

ASSESSMENT

Cardiac MRI data, including left ventricular functional, segmental native T1, and oxygenation signal-intensity (SI) according to AHA 17-segment model, were acquired. Patients were divided into LGE+ and LGE- groups. In patients with LGE, all segments were further classified as positive or negative segments by segmentally presence/absence of LGE.

STATISTICAL TESTS

Variables were compared using Student's t, Wilcoxon, Kruskal-Wallis test and one-way analysis of variance. Bivariate Pearson or Spearman correlation were calculated to determine association between oxygenation SI and native T1. Variables with P < 0.10 in the univariable analysis were included in multivariable model. Receiver operating characteristic analysis was used to assess the performance of OS in diagnosing myocardial hypoxia.

RESULTS

The myocardial oxygenation SI of DMD was significantly decreased in all segments compared with normal controls, and more obvious in the LGE+ segments (0.46 ± 0.03 vs. 0.52 ± 0.03). For patients with and without LGE, myocardial oxygenation SI were significantly negatively correlated with native T1 in all segments (r = -0.23 to -0.42). The inferolateral oxygenation SI was a significant independent associator of LGE presence (adjusted OR = 0.900).

DATA CONCLUSION

Myocardial hypoxia evaluated by the OS-Cardiac-MRI indeed occurs in DMD and associate with myocardial fibrosis, which might be used as a biomarker in assessing myocardial damage in DMD.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 1.

Evaluation of cardiac remodeling in pediatric chronic kidney disease by cardiovascular magnetic resonance

BACKGROUND

Children with chronic kidney disease (CKD) are at high risk of cardiovascular disease. Cardiovascular magnetic resonance (CMR) is the reference method for assessing cardiac remodeling. To our knowledge, no study has reported a comprehensive analysis of left ventricular(LV) cardiac remodeling using CMR in different stages of pediatric CKD. This prospective case-control study aimed to investigate cardiac remodeling in pediatric CKD, using CMR, and determine its relationship with risk factors.

METHOD

CMR was performed in 124 children with CKD and 50 controls. The cardiac remodeling parameters included left ventricular mass index (LVMI), LV remodeling index (LVRI), and LV wall thickness. Univariable and multivariable analyses were performed to assess the cardiac remodeling risk factors.

RESULTS

Cardiac remodeling was observed in 35.5% (44/124) of children with CKD. The LVMI, LVRI, and LV wall thickness were higher in advanced stages of CKD (P < 0.05). In the CKD stage 1-2 group, a lower in the estimated glomerular filtration rate was an independent determinant of impaired LVMI (β = -0.425, P = 0.019) and LVRI (β = -0.319, P = 0.044). A higher protein to creatinine ratio(PCR) was independently associated with impaired LVRI (β = 0.429, P = 0.022). In the CKD stage 3-5 group, higher in systolic blood pressure (SBP) (β = 0.464, P = 0.005) and PCR (β = 0.852, P = 0.031) were independent determinants of impaired LVMI. Additionally, higher SBP was positively correlated with impaired LVRI(r = 0.599, P < 0.001). There was a trend toward more abnormal cardiac remodeling in the CKD stage 3-5 group with hypertension than those without.

CONCLUSION

Cardiac remodeling is prevalent in children with CKD, from an early stage. kidney markers are independently associated with cardiac remodeling. Hypertension increases the risk of cardiac remodeling in CKD stages 3-5. Strict BP control may help reverse or prevent remodeling.

Case Report: Acute myocarditis in a patient with Duchenne muscular dystrophy

Background

Cardiovascular complications are the leading cause of death among individuals with Duchenne muscular dystrophy (DMD). However, due to the difficulty in evaluating individuals with inactive DMD, acute myocardial injury may be overlooked.

Case presentation

An 11-year-old boy with DMD presented to the emergency department with a 5-day history of persistent nasal congestion, runny nose, and cough. He was regularly taking prednisolone acetate, angiotensin-converting enzyme (ACE) inhibitors, and β-blockers for suspected DMD-associated cardiomyopathy. Upon presentation, a substantially elevated cardiac troponin I (cTnI) level of 19.8 μg/L and abnormal electrocardiogram (ECG) results were detected. Further cardiac magnetic resonance imaging (CMR) showed myocardial inflammation with localized T2 hyperintensity from the basal to middle lateral and inferior walls, as well as late gadolinium enhancement (LGE) from the basal to apical inferior lateral walls, supporting a diagnosis of acute myocarditis. Subsequently, the patient showed clinical improvement in response to combination treatment with intravenous immunoglobulin, oral prednisolone acetate, potassium chloride sustained-release tablets, anti-heart failure medication, and broad-spectrum antibiotics.

Conclusions

We report a rare case of acute myocarditis in a patient with DMD, potentially due to upper respiratory tract infection. This case highlights the importance of early myocarditis recognition and treatment in patients with DMD.

Derivation and validation of diagnostic models for myocardial fibrosis in duchenne muscular dystrophy: assessed by multi-parameter cardiovascular magnetic resonance

BACKGROUND

Gadolinium-enhanced cardiovascular magnetic resonance (CMR) is the most widely used approach for diagnosing myocardial fibrosis with late gadolinium enhancement (LGE) in cardiomyopathy associated with Duchenne muscular dystrophy. Given the limitations and safety of gadolinium use, we wanted to develop and evaluate multi-parametric pre-contrast CMR models for the diagnosis of LGE and investigate whether they could be utilised as surrogates for LGE in DMD patients.

METHODS

A total of 136 DMD patients were prospectively recruited and separated into LGE - and LGE + groups. In the first subset of patients (derivation cohort), regression models for the diagnosis of LGE were built by logistic regression using pre-contrast sequence parameters. In a validation cohort of other patients, the models' performances were evaluated.

RESULTS

EF, native T1 and longitudinal strain alone, as well as their combinations form seven models. The model that included EF, native T1 and longitudinal strain had the best diagnostic value, but there was no significant difference in diagnostic accuracy among the other models except EF. In the validation cohort, the diagnosis outcomes of models were moderate consistent with the existence of LGE. The longitudinal strain outperformed the other models in terms of diagnostic value (sensitivity: 83.33%, specificity: 54.55%).

CONCLUSIONS

Pre-contrast sequences have a moderate predictive value for LGE. Thus, pre-contrast parameters may be considered only in a specific subset of DMD patients who cannot cooperate for long-time examinations and have contradiction of contrast agent to help predict the presence of LGE.

TRIAL REGISTRATION NUMBER (TRN)

ChiCTR1800018340 DATE OF REGISTRATION: 20180107.

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

Background The prognostic utility of cardiovascular magnetic resonance imaging, including strain analysis and tissue characterization, has not been comprehensively investigated in adult patients with muscular dystrophy. Methods and Results We prospectively enrolled 148 patients with dystrophinopathies (including heterozygotes), limb-girdle muscular dystrophy, and type 1 myotonic dystrophy (median age, 36.0 [interquartile range, 23.0-50.0] years; 51 [34.5%] women) over 7.7 years in addition to an age- and sex-matched healthy control cohort (n=50). Cardiovascular magnetic resonance markers, including 3-dimensional strain and fibrosis, were assessed for their respective association with major adverse cardiac events. Our results showed that markers of contractile performance were reduced across all muscular dystrophy groups. In particular, the dystrophinopathies cohort experienced reduced left ventricular (LV) ejection fraction and high burden of replacement fibrosis. Patients with type 1 myotonic dystrophy showed a 26.8% relative reduction in LV mass with corresponding reduction in chamber volumes. Eighty-two major adverse cardiac events occurred over a median follow-up of 5.2 years. Although LV ejection fraction was significantly associated with major adverse cardiac events (adjusted hazard ratio [aHR], 3.0 [95% CI, 1.4-6.4]) after adjusting for covariates, peak 3-dimensional strain amplitude demonstrated greater predictive value (minimum principal amplitude: aHR, 5.5 [95% CI, 2.5-11.9]; maximum principal amplitude: aHR, 3.3 [95% CI, 1.6-6.8]; circumferential amplitude: aHR, 3.4 [95% CI, 1.6-7.2]; longitudinal amplitude: aHR, 3.4 [95% CI, 1.7-6.9]; and radial strain amplitude: aHR, 3.0 [95% CI, 1.4-6.1]). Minimum principal strain yielded incremental prognostic value beyond LV ejection fraction for association with major adverse cardiac events (change in χ2=13.8; P<0.001). Conclusions Cardiac dysfunction is observed across all muscular dystrophy subtypes; however, the subtypes demonstrate distinct phenotypic profiles. Myocardial deformation analysis highlights unique markers of principal strain that improve risk assessment over other strain markers, LV ejection fraction, and late gadolinium enhancement in this vulnerable patient population.

Myocardial native T1 mapping and extracellular volume quantification in asymptomatic female carriers of Duchenne muscular dystrophy gene mutations

BACKGROUND

Female carriers of dystrophin gene mutations (DMD-FC) were previously considered non-manifesting, but in recent decades, cardiomyopathy associated with muscular dystrophy and myocardial fibrosis has been described. Our study aimed to assess prospectively myocardial fibrosis in asymptomatic DMD-FC compared to a sex-matched control group (CG) with similar age distribution using native T1 mapping and extracellular volume (ECV) quantification by cardiovascular magnetic resonance (CMR) imaging.

MATERIALS AND METHODS

38 DMD-FC with verified genetic mutation and 22 healthy volunteers were included. Using CMR, native T1 relaxation time and ECV quantification were determined in each group. Late gadolinium enhancement (LGE) was assessed in all cases.

RESULTS

There were 38 DMD-FC (mean age 39.1 ± 8.8 years) and 22 healthy volunteers (mean age 39.9 ± 12.6 years) imagined by CMR. The mean global native T1 relaxation time was similar for DMD-FC and CG (1005.1 ± 26.3 ms vs. 1003.5 ± 25.0 ms; p-value = 0.81). Likewise, the mean global ECV value was also similar between the groups (27.92 ± 2.02% vs. 27.10 ± 2.89%; p-value = 0.20). The segmental analysis of mean ECV values according to the American Heart Association classification did not show any differences between DMD-FC and CG. There was a non-significant trend towards higher mean ECV values of DMD-FC in the inferior and inferolateral segments of the myocardium (p-value = 0.075 and 0.070 respectively).

CONCLUSION

There were no statistically significant differences in the mean global and segmental native T1 relaxation times and the mean global or segmental ECV values. There was a trend towards higher segmental mean ECV values of DMD-FC in the inferior and inferolateral walls of the myocardium.