For many neuromuscular diseases (NMDs), cardiac disease represents a major cause of morbidity and mortality. The management of cardiac disease in NMDs is made challenging by the broad clinical ...heterogeneity that exists among many NMDs and by limited knowledge about disease-specific cardiovascular pathogenesis and course-modifying interventions. The overlay of compromise in peripheral muscle function and other organ systems, such as the lungs, also makes the simple application of endorsed adult or pediatric heart failure guidelines to the NMD population problematic. In this statement, we provide background on several NMDs in which there is cardiac involvement, highlighting unique features of NMD-associated myocardial disease that require clinicians to tailor their approach to prevention and treatment of heart failure. Undoubtedly, further investigations are required to best inform future guidelines on NMD-specific cardiovascular health risks, treatments, and outcomes.
Management of Kawasaki disease in adults Denby, Kara J; Clark, Daniel E; Markham, Larry W
Heart (British Cardiac Society),
11/2017, Volume:
103, Issue:
22
Journal Article
Peer reviewed
Kawasaki disease is the most common childhood vasculitis in the USA and the most common cause of acquired cardiac disease in children in developed countries. Since the vast majority of Kawasaki ...disease initially presents at <5 years of age, many adult cardiologists are unfamiliar with the pathophysiology of this disease. This vasculitis has a predilection for coronary arteries with a high complication rate across the lifespan for those with medium to large coronary artery aneurysms. An inflammatory cascade produces endothelial dysfunction and damage to the vascular wall, leading to aneurysmal dilatation. Later, pseudonormalisation of the vascular lumen occurs through vascular remodelling and layering thrombus, but this does not necessarily indicate resolution of disease or reduction of risk for future complications. There is a growing prevalence of Kawasaki disease, making it increasingly relevant for adult cardiologists as this population transitions into adulthood. As the 2017 American Heart Association (AHA) and 2014 Japanese Circulation Society (JCS) guidelines emphasise, Kawasaki disease requires rigorous follow-up with cardiac stress testing and non-invasive imaging to detect progressive stenosis, thrombosis and luminal occlusion that may lead to myocardial ischaemia and infarction. Due to differences in disease mechanisms, coronary disease due to Kawasaki disease should be managed with different pharmacological and non-pharmacological treatment algorithms than atherosclerotic coronary disease. This review addresses gaps in the current knowledge of the disease and its optimal treatment, differences in the AHA and JCS guidelines, targets for future research and obstacles to transition of care from adolescence into adulthood.
Thoracic aortic aneurysm and dissection (TAAD) is typically inherited in an autosomal dominant manner, but rare X-linked families have been described. So far, the only known X-linked gene is FLNA, ...which is associated with the periventricular nodular heterotopia type of Ehlers-Danlos syndrome. However, mutations in this gene explain only a small number of X-linked TAAD families.
We performed targeted resequencing of 368 candidate genes in a cohort of 11 molecularly unexplained Marfan probands. Subsequently, Sanger sequencing of BGN in 360 male and 155 female molecularly unexplained TAAD probands was performed.
We found five individuals with loss-of-function mutations in BGN encoding the small leucine-rich proteoglycan biglycan. The clinical phenotype is characterized by early-onset aortic aneurysm and dissection. Other recurrent findings include hypertelorism, pectus deformity, joint hypermobility, contractures, and mild skeletal dysplasia. Fluorescent staining revealed an increase in TGF-β signaling, evidenced by an increase in nuclear pSMAD2 in the aortic wall. Our results are in line with those of prior reports demonstrating that Bgn-deficient male BALB/cA mice die from aortic rupture.
In conclusion, BGN gene defects in humans cause an X-linked syndromic form of severe TAAD that is associated with preservation of elastic fibers and increased TGF-β signaling.
Genet Med19 4, 386–395.
Cardiomyopathy is the leading cause of death in Duchenne muscular dystrophy (DMD), but studies suggest heart failure biomarkers correlate poorly with cardiomyopathy severity. DMD clinical trials have ...used troponin I (cTnI) as a biomarker of toxicity, but it is unclear if asymptomatic DMD patients have elevated cTnI. We longitudinally evaluated cTnI, brain natriuretic peptide (BNP), and N-terminal pro-BNP (NT-proBNP) in a DMD cohort.
DMD patients were prospectively enrolled and followed for 3 years. Serum was drawn at the time of cardiac magnetic resonance (CMR). Normal biomarker values were derived from healthy subjects. Biomarkers were correlated with CMR markers.
All subjects were asymptomatic at the time of enrollment. Several DMD subjects had transiently elevated cTnI. Those with elevated cTnI were more likely to have late gadolinium enhancement on baseline CMR. NT-proBNP correlated with indexed left ventricular end diastolic and maximum left atrial volumes. Otherwise, standard cardiac biomarkers did not correlate with CMR markers of cardiomyopathy.
CTnI, BNP, and NT-proBNP do not correlate with CMR assessment of cardiomyopathy progression. A subset of DMD patients have asymptomatic cTnI leak of uncertain clinical significance, though of critical importance if cTnI is used to assess for cardiac toxicity in future drug trials.
Asymptomatic patients with Duchenne muscular dystrophy (DMD) exhibit transient troponin I leak. NT-proBNP correlated with indexed left ventricular end diastolic volume and indexed maximum left atrial volume. Other cardiac biomarkers did not correlate with cardiac magnetic resonance (CMR) markers of cardiomyopathy.
Patients with Duchenne muscular dystrophy (DMD) require frequent imaging to assess left ventricular (LV) function. Poor imaging windows can limit the diagnostic utility of echocardiography. Cardiac ...magnetic resonance imaging (CMR) is the gold standard for the assessment of LV function but has not been universally adopted in patients with DMD. The study objectives were (1) to evaluate the reproducibility of echocardiographic measures of LV function, (2) to evaluate which echocardiographic methods correlate best with CMR LV ejection fraction (LVEF), and (3) to evaluate whether CMR provides additional value compared with echocardiography.
Twenty-eight participants with DMD prospectively underwent echocardiography and CMR. Two blinded readers measured fractional shortening from M-mode and two-dimensional images and LVEF using four-chamber, biplane Simpson, 5/6 area-length, and three-dimensional methods. Speckle-tracking echocardiography was used to analyze circumferential strain. Readers subjectively rated function and segmental wall motion. Agreement was assessed using intraclass correlation coefficients, Bland-Altman plots, Spearman correlation, and weighted κ.
Two-dimensional fractional shortening and 5/6 area-length LVEF had the best combination of reproducibility and correlation with CMR LVEF, though both misclassified approximately 20% as either normal or abnormal function. Other measures of LV function were less reproducible, with worse correlations with CMR LVEF. Thirty-seven percent of segments not visible on echocardiography were believed to have wall motion abnormalities by CMR.
Two-dimensional fractional shortening and 5/6 area-length LVEF represent the most accurate and reproducible echocardiographic measures of LV function in patients with DMD. CMR should be considered when neither of these techniques is measurable or when it is necessary to detect more subtle cardiovascular changes.
Cardiomyopathy is the leading cause of death in Duchenne muscular dystrophy (DMD). Cardiac magnetic resonance (CMR) parametric mapping sequences offer insights into disease pathophysiology. We ...propose a novel approach by leveraging T2 mapping in conjunction with T1 and extracellular volume (ECV) mapping to perform a virtual myocardial biopsy. While previous work has attempted to describe myocardial changes in DMD, our inclusion of T2 mapping enables comprehensive categorization of myocardial tissue characteristics of fibrosis, edema, and fat to better understand the pathological composition of the myocardium with disease progression.
DMD patients (n = 49; median: 12 years-old) underwent CMR, including T1, T2, and ECV. Categories were defined as normal, isolated high T1 (normal ECV, high T1, normal T2), fibrosis (high ECV, normal or high T1, normal T2), edema (normal or high ECV, normal or high T1, high T2), fat (normal ECV, low T1, high T2) or fibrofatty (high ECV, low T1, high T2).
Median left ventricular ejection fraction (LVEF) was 59% with 27% having LVEF < 55%. Those with normal LVEF and no late gadolinium enhancement (37%) were younger in age (10.5 ± 2.6 vs. 15.0 ± 4.3 years-old, p < 0.001). Native T1 was elevated in at least one slice in 82% of patients. Those with high T2 at any slice (27%) were older (p = 0.005) and had lower LVEF (p = 0.005) compared with subjects with normal T2 (73%). The most common myocardial characterization was fibrosis (43%) followed by isolated high T1 (24%). Of the 13 with high T2, ten were categorized as edema, two as fibrofatty, and one as fat.
CMR parametric mapping sequences offer insights into Duchenne cardiomyopathy pathophysiology, which should drive development of therapeutic interventions aimed at these targets. Myocardial fibrosis is common in DMD. Patients with elevated T2 were older and had lower LVEF. Though fat infiltration was present, the majority of subjects with elevated T2 met criteria for myocardial edema.
Duchenne muscular dystrophy (DMD) leads to progressive cardiomyopathy. Detection of myocardial fibrosis with late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) is critical ...for clinical management. Due to concerns of brain deposition of gadolinium, non-contrast methods for detecting and monitoring myocardial fibrosis would be beneficial.
We hypothesized that native T1 mapping and/or circumferential (ε
) and longitudinal (ε
) strain can detect myocardial fibrosis.
156 CMRs with gadolinium were performed in 66 DMD boys and included: (1) left ventricular ejection fraction (LVEF), (2) LGE, (3) native T1 mapping and myocardial tagging (ε
measured using harmonic phase analysis). LGE was graded as: (1) presence/absence by segment, slice, and globally; (2) global severity from 0 (no LGE) to 4 (severe); (3) percent LGE using full width half maximum (FWHM). ε
and ε
measured using feature tracking. Regression models to predict LGE included native T1 and either ε
or ε
and ε
measured at each segment, slice, and globally.
Mean age and LVEF at first CMR were 14 years and 54%, respectively. Global ε
and ε
strongly predicted presence or absence of LGE (OR 2.6 1.1, 6.0, p = 0.029, and OR 2.3 1.0, 5.1, p = 0.049, respectively) while global native T1 did not. Global ε
, ε
, and native T1 predicted global severity score (OR 2.6 1.4, 4.8, p = 0.002, OR 2.6 1.4, 6.0, p = 0.002, and OR 1.8 1.1, 3.1, p = 0.025, respectively). ε
correlated with change in LGE by severity score (n = 33, 3.8 1.0, 14.2, p = 0.048) and ε
correlated with change in percent LGE by FWHM (n = 34, OR 0.2 0.1, 0.9, p = 0.01).
Pre-contrast sequences predict presence and severity of LGE, with ε
and ε
being more predictive in most models, but there was not an observable advantage over using LVEF as a predictor. Change in LGE was predicted by ε
(global severity score) and ε
(FWHM). While statistically significant, our results suggest these sequences are currently not a replacement for LGE and may only have utility in a very limited subset of DMD patients.
Cardiomyopathy (CMP) is the most common cause of mortality in Duchenne muscular dystrophy (DMD), though the age of onset and clinical progression vary. We applied a novel 4D (3D + time) strain ...analysis method using cine cardiovascular magnetic resonance (CMR) imaging data to determine if localized strain metrics derived from 4D image analysis would be sensitive and specific for characterizing DMD CMP.
We analyzed short-axis cine CMR image stacks from 43 DMD patients (median age: 12.23 yrs 10.6–16.5; interquartile range) and 25 male healthy controls (median age: 16.2 yrs 13.3–20.7). A subset of 25 male DMD patients age-matched to the controls (median age: 15.7 yrs 14.0-17.8) was used for comparative metrics. CMR images were compiled into 4D sequences for feature-tracking strain analysis using custom-built software. Unpaired t-test and receiver operator characteristic area under the curve (AUC) analysis were used to determine statistical significance. Spearman's rho was used to determine correlation.
DMD patients had a range of CMP severity: 15 (35% of total) had left ventricular ejection fraction (LVEF) > 55% with no findings of myocardial late gadolinium enhancement (LGE), 15 (35%) had findings of LGE with LVEF > 55% and 13 (30%) had LGE with LVEF < 55%. The magnitude of the peak basal circumferential strain, basal radial strain, and basal surface area strain were all significantly decreased in DMD patients relative to healthy controls (p < 0.001) with AUC values of 0.80, 0.89, and 0.84 respectively for peak strain and 0.96, 0.91, and 0.98 respectively for systolic strain rate. Peak basal radial strain, basal radial systolic strain rate, and basal circumferential systolic strain rate magnitude values were also significantly decreased in mild CMP (No LGE, LVEF > 55%) compared to a healthy control group (p< 0.001 for all). Surface area strain significantly correlated with LVEF and extracellular volume (ECV) respectively in the basal (rho = − 0.45, 0.40), mid (rho = − 0.46, 0.46), and apical (rho = − 0.42, 0.47) regions.
Strain analysis of 3D cine CMR images in DMD CMP patients generates localized kinematic parameters that strongly differentiate disease from control and correlate with LVEF and ECV.
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