Cardiac mesenchymal stromal cells are a source of adipocytes in arrhythmogenic cardiomyopathy

AIM

Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder mainly due to mutations in desmosomal genes, characterized by progressive fibro-adipose replacement of the myocardium, arrhythmias, and sudden death. It is still unclear which cell type is responsible for fibro-adipose substitution and which molecular mechanisms lead to this structural change. Cardiac mesenchymal stromal cells (C-MSC) are the most abundant cells in the heart, with propensity to differentiate into several cell types, including adipocytes, and their role in ACM is unknown. The aim of the present study was to investigate whether C-MSC contributed to excess adipocytes in patients with ACM.

METHODS AND RESULTS

We found that, in ACM patients' explanted heart sections, cells actively differentiating into adipocytes are of mesenchymal origin. Therefore, we isolated C-MSC from endomyocardial biopsies of ACM and from not affected by arrhythmogenic cardiomyopathy (NON-ACM) (control) patients. We found that both ACM and control C-MSC express desmosomal genes, with ACM C-MSC showing lower expression of plakophilin (PKP2) protein vs.

CONTROLS

Arrhythmogenic cardiomyopathy C-MSC cultured in adipogenic medium accumulated more lipid droplets than controls. Accordingly, the expression of adipogenic genes was higher in ACM vs. NON-ACM C-MSC, while expression of cell cycle and anti-adipogenic genes was lower. Both lipid accumulation and transcription reprogramming were dependent on PKP2 deficiency.

CONCLUSIONS

Cardiac mesenchymal stromal cells contribute to the adipogenic substitution observed in ACM patients' hearts. Moreover, C-MSC from ACM patients recapitulate the features of ACM adipogenesis, representing a novel, scalable, patient-specific in vitro tool for future mechanistic studies.

Measurements of growth hormone and insulin-like growth factor 1 in cats with diabetes mellitus

Serum concentrations of insulin-like growth factor 1 (IGF-1) and growth hormone were measured in 25 cats with untreated diabetes mellitus (11 of which were used for follow-up measurements, one to three, four to eight, nine to 12 and 13 to 16 weeks after their treatment with insulin began), 14 diabetic cats that had previously been treated with insulin, and seven diabetic cats that also had hypersomatotropism, two of which had not previously been treated with insulin; 18 healthy cats were used as controls. In the untreated diabetic cats the concentration of IGF-1 ranged from 13.0 to 433.0 ng/ml (median 170.5 ng/ml), which was significantly lower than the concentrations in the control cats (196.0 to 791.0 ng/ml, median 452.0 ng/ml). Their IGF-1 concentrations increased significantly when they were treated with insulin and after four to eight weeks were not different from those in the control cats. In the diabetic cats that had previously been treated with insulin the IGF-1 concentrations were 33.0 to 476.0 ng/ml (median 316.0 ng/ml), which was significantly lower than the concentrations in the control cats, but significantly higher than in the untreated diabetic cats. The IGF-1 concentrations in the two previously untreated diabetic cats with hypersomatotropism were low and low-normal but increased markedly after treatment with insulin. In the five previously treated cats with hypersomatotropism the concentration of IGF-1 was above the normal range. The concentrations of growth hormone in the treated and untreated diabetic cats without hypersomatotropisms were not significantly different and there was an overlap in its concentrations in the diabetic cats with and without hypersomatotropism.

Home monitoring of blood glucose concentration by owners of diabetic dogs

The objective of this study was to investigate whether home monitoring of blood glucose of diabetic dogs by owners would be possible on a long-term basis. The owners of 12 diabetic dogs were each asked to generate four glucose curves by taking capillary blood samples from their dog's ear, at three- to four-week intervals. Within one week of each curve being produced by the owner, an additional curve was produced by a veterinarian in the hospital. Ten owners were able to generate blood glucose curves; three of them needed a second demonstration, and two telephoned for further guidance. The blood glucose concentrations obtained from the first two 'hospital' curves were significantly lower than those measured at home. Overall, in 42 per cent of cases, the treatment based on the hospital curves would have been different from that based on 'home' curves. The results of this study indicate that the majority of owners were able and willing to perform long-term monitoring of the blood glucose concentrations of their dogs.

Impact of coercive tactics on the decision-making of adolescents with intellectual disabilities

BACKGROUND

High rates of victimization have raised concerns about the ability of adolescents with intellectual disabilities (ID) to avoid and escape from harmful situations and to make decisions in their own best interest. The present study was designed to assess the impact of specific coercive tactics on the decision-making of adolescents with ID.

METHOD

Forty-eight adolescents with ID participated in the study. They were asked to respond to a series of brief vignettes depicting equal numbers of situations involving coercion with a lure, coercion with a threat, and no specific coercive tactic. Performance was assessed in terms of independent, prevention-focused decisions, reporting decisions and responses to fact and inference comprehension questions.

RESULTS

Overall, participants suggested independent, prevention-focused decisions only about half the time. They were more likely to suggest independent, prevention-focused decisions in situations with no specific coercive tactic or coercion with a lure than in situations involving a threat. However, reporting decisions were more likely in situations involving coercion with a threat than in the other two conditions and both fact and inference comprehension were best in situations involving coercion with a threat.

CONCLUSIONS

Results indicated that adolescents with ID are not well-prepared to handle situations on their own that involve coercion, especially coercion with a threat. Because comprehension did not appear to be a key source of the decision-making difficulty in this study, further research is needed to examine all aspects of the decision-making process as a basis for the design of effective interventions.

Spontaneous chromosome loss and colcemid resistance in lymphocytes from patients with myotonic dystrophy type 1

Myotonic Dystrophy type 1 (DM1) is one of the many inherited human diseases whose molecular defect is the expansion of a trinucleotide DNA sequence. DM1 shares with fragile X syndrome (FMR1), another "unstable triplet syndrome", several molecular features not present in the remaining triplet diseases. As FMR1 is also characterised by chromosome instability at the site of the expanded triplet, lymphocytes from DM1 patients and healthy donors were cultured for micronucleus (MN) analysis, in order to verify if DM1 is also prone to chromosome instability. A FISH analysis was also carried out to detect the presence of centromeric sequences in the observed MN. The data indicate that DM1 patients present a percentage of centromere-positive MN significantly higher than controls, suggesting that chromosome loss is the main mechanism underlying the origin of the increased spontaneous instability. To further assess the proneness to instability of cells of DM1 patients, cultures from patients and controls were treated in vitro with growing concentrations of two different mutagens: colcemid, a "pure" aneugen compound whose target is tubulin, and mytomicin C, a strong clastogen. The results show that the patient group is significantly less sensitive to colcemid. These data, together with FISH analysis, suggest the presence, in DM1 patients, of an already damaged tubulin, which becomes no more sensitive to the effect of colcemid and which could be the main defect underlying the aneugenic effects in DM1.

Validity, diagnostics and feasibility of the Italian version of the Montreal Cognitive Assessment (MoCA) in Huntington's disease

BACKGROUND

This study is aimed at assessing the clinimetric properties and feasibility of the Italian version of the Montreal Cognitive Assessment (MoCA) in patients with Huntington's disease (HD).

METHODS

N = 39 motor-manifest HD patients, N = 74 Parkinson's disease (PD) patients and N = 92 matched HCs were administered the MoCA. HD patients further underwent the Unified Huntington's Disease Rating Scale (UHDRS), self-report questionnaires for anxiety and depression and a battery of first- and second-level cognitive tests. Construct validity was tested against cognitive and behavioural/psychiatric measures, whereas ecological validity against motor-functional subscales of the UHDRS. Sensitivity to disease severity was tested, via a logistic regression, by exploring whether the MoCA discriminated between patients in Shoulson-Fahn stage ≤ 2 vs. > 2. The same analysis was employed to test its ability to discriminate HD patients from HCs and PD patients.

RESULTS

The MoCA converged towards cognitive and behavioural measures but diverged from psychiatric ones, being also associated with motor/functional measures from the UHDRS. In identifying patients with cognitive impairment, adjusted MoCA scores were highly accurate (AUC = .92), yielding optimal diagnostics at the cut-off of < 19.945 (J = .78). The MoCA was able to discriminate patients in the middle-to-advanced from those in the early-to-middle stages of the disease (p = .037), as well as to differentiate HD patients from both HCs (p < .001) and PD patients (p < .001).

CONCLUSIONS

The MoCA is a valid, diagnostically sound and feasible cognitive screener in motor-manifest HD patients, whose adoption is thus encouraged in clinical practice and research.

"I Wouldn't Even Know What to Ask for": Patients' and Caregivers' Experiences of Psychological Support for Huntington's Disease in Italy

People with Huntington's disease (HD) often experience psychological difficulties linked with disease progression and the adjustment to living with a chronic condition, which are also frequently shared by their informal caregivers (e.g., partners). Although limited, the current literature on psychological care for people with HD shows that interventions have the potential to drive improvements in mental health and quality of life. However, the experience of accessing and receiving psychological support for HD remains unclear across several countries. This study adopted a qualitative design to explore the experiences of psychological support for HD from the perspectives of patients and caregivers living in Italy. Semi-structured interviews were carried out with 14 participants-7 patients with early-manifest HD and 7 partners acting as their caregivers. The resulting data were analysed through thematic analysis. Four overarching themes were identified: (1) the availability of psychological support for HD, (2) barriers to accessing psychological support, (3) enablers to accessing psychological support, and (4) the future development of public psychological provision for HD. In Italy, patients and caregivers perceive public psychological support for HD as unavailable or inadequate, and private therapy is often seen as unaffordable. Barriers such as distrust in public healthcare and preconceptions about therapy may limit access, while advice from HD organisations and seeking therapy for other reasons may act as enablers. A strong emphasis is put on the need for accessible public psychological support throughout all the stages of the condition.

The association between low skeletal muscle mass and delirium: results from the nationwide multi-centre Italian Delirium Day 2017

INTRODUCTION

Delirium and sarcopenia are common, although underdiagnosed, geriatric syndromes. Several pathological mechanisms can link delirium and low skeletal muscle mass, but few studies have investigated their association. We aimed to investigate (1) the association between delirium and low skeletal muscle mass and (2) the possible role of calf circumference mass in finding cases with delirium.

METHODS

The analyses were conducted employing the cross-sectional "Delirium Day" initiative, on patient 65 years and older admitted to acute hospital medical wards, emergency departments, rehabilitation wards, nursing homes and hospices in Italy in 2017. Delirium was diagnosed as a 4 + score at the 4-AT scale. Low skeletal muscle mass was operationally defined as calf circumference ≤ 34 cm in males and ≤ 33 cm in females. Logistic regression models were used to investigate the association between low skeletal muscle mass and delirium. The discriminative ability of calf circumference was evaluated using non-parametric ROC analyses.

RESULTS

A sample of 1675 patients was analyzed. In total, 73.6% of participants had low skeletal muscle mass and 24.1% exhibited delirium. Low skeletal muscle mass and delirium showed an independent association (OR: 1.50; 95% CI 1.09-2.08). In the subsample of patients without a diagnosis of dementia, the inclusion of calf circumference in a model based on age and sex significantly improved its discriminative accuracy [area under the curve (AUC) 0.69 vs 0.57, p < 0.001].

DISCUSSION AND CONCLUSION

Low muscle mass is independently associated with delirium. In patients without a previous diagnosis of dementia, calf circumference may help to better identify those who develop delirium.

Heimmonitoring des Blutglukosespiegels durch Besitzer diabetischer Hunde und Katzen

Generation of blood glucose curves is essential to monitor glycemic control in dogs and cats with diabetes mellitus. Up till now blood collection and blood glucose measurements could only be performed in a hospital. However, glucose concentrations measured in a hospital environment can markedly differ from concentrations measured at home, due to reduced appetite, different activity level and stressful handling. At the Clinic of Small Animal Internal Medicine, University of Zurich, a new method to collect capillary blood from the ear and to measure blood glucose by means of a portable glucose meter has been developed. This method enables owners of diabetic dogs or cats to determine blood glucose concentrations and generate blood glucose curves at home. Three cases demonstrate, how much blood glucose concentrations at home may differ from those in the hospital and how home monitoring can help to establish diabetic control in dogs and cats.

Internal medicine inpatients' prevalence of misdiagnosed severe osteoporosis

Vertebral fractures (VF) related to osteoporosis (i.e., severe OP) increase the risk of disability and mortality, but they are often neglected. We observed a severe OP misdiagnosis in 28.9% of inpatients with previous spinal imaging positive for VFs. Diagnosing severe OP is crucial to reduce the health care costs of inpatients.

INTRODUCTION

Vertebral fractures (VFs) related to osteoporosis (OP) increase the risk of additional fractures and death. In inpatients, VFs are often neglected with consequent delay in OP treatments, prolongation of hospitalization, and reduction of life expectancy. The aim of this study was to evaluate the prevalence of a misdiagnosed severe OP (i.e., with VF) in general medicine inpatients.

METHODS

We evaluated inpatients of a Medicine Unit between January 2019 and December 2019 without severe OP diagnosis, who had spinal imaging. For each patient, we collected demographic data, previous or current OP treatment, and presence/number of VFs. Descriptive data were presented by medians (interquartile range [IQR]) for continuous data or as numbers (percentages) for categorical data. Differences between subgroups were analyzed with chi-square or Kruskal-Wallis tests as appropriate. p-values <0.05 were considered statistically significant.

RESULTS

793 subjects were admitted to inpatient's clinic: 235 (135 females and 100 males with a median age of 76.0 [64.0-83.0] years) were enrolled. One or more vertebral fractures were present in 28.9% (68/235) subjects; 47% (32/68) had two or more vertebral fractures. The majority of patients (55/68) with VFs had not previously received a severe OP diagnosis.

CONCLUSIONS

Severe OP was misdiagnosed in at least 8.6% of inpatients. The prevalence dramatically increases (about 29%) in subjects with previous spinal imaging showing one or more VFs. More attention should be given to this co-morbidity, which is known to be an additional risk factor for disability and mortality.

P3682Myocardial structural abnormalities in nonischemic patients presenting with ventricular arrhythmias

Background

The diagnosis of concealed cardiomyopathies in patients with ventricular arrhythmias (VAs) is one of the major challenging issues faced by physicians.

Purpose

We aimed at reporting the cardiomyopathic substrate in patients with recurrent arrhythmias of ventricular origin.

Methods

Consecutive patients with unexplained VAs underwent a complete diagnostic work-out, including endomyocardial biopsy (EMB).

Results

Ninety-seven patients were enrolled (76.3% male, age 39.7±13.3 yrs). The presenting arrhythmic manifestation was aborted cardiac arrest in 30 (30.9%) patients, sustained ventricular tachycardia (VT) in 9 (9.3%), nonsustained VT in 15 (15.5%) and frequent premature ventricular complexes in 43 (44.3%). Overall, 350 biopsies were collected (3.6/patient). The incidence of procedure-related complications was 5.1% (n=5): 4 major complications (1 rupture of a tricuspid chorda tendinea w/o hemodynamic impairment, 1 dissection of right external iliac artery treated with stent, 1 thrombotic occlusion of left superficial femoral artery which required surgical treatment, 1 TIA) and 1 minor complication (groin hematoma) occurred. The final diagnosis was arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) (n=41; 42.3%), followed by myocarditis (n=20; 20.6%), dilated cardiomyopathy (n=6; 6.2%), cardiac sarcoidosis (n=6; 6.2%), and myocarditis in ARVD/C (n=5; 5.1%). Among the 25 patients whose final diagnosis was consistent with myocarditis, an acute stage of the disease was documented in 7 (7.2%), while a chronic myocarditis in 18 (18.5%). Additionally, according to medical history and diagnostic workout, in 2 of the 6 patients the dilated cardiomyopathy had a likely post-inflammatory etiology. Absence of myocardial abnormalities was documented in 15 (15.5%) patients: this group included 1 case of methadone-induced torsade de pointes. The remaining 4 (4.1%) patients were diagnosed with a cardiac hypertrophy (n=2, 2.1%, secondary to exercise or Fabry disease), a dilated mitochondrial cardiomyopathy (n=1, 1.0%), a dilated cardiomyopathy in Emery-Dreifuss muscular dystrophy (n=1; 1.0%).

Conclusion

In our series, approximately 45% of patients with unexplained VAs had a final diagnosis of ARVD/C.

P3684Detecting true left dominant arrhythmogenic cardiomyopathy: cardiac magnetic resonance imaging and an invasive diagnostic assessment to go beyond current diagnostic criteria

Background

Left-dominant arrhythmogenic cardiomyopathy (LDACM) represents an underdiagnosed subtype of the classical right-dominant ACM, with a fibro-fatty infiltration of the left ventricle ab disease initio. To date, ACM diagnosing criteria do not include any paradigm for LDACM and no shared consensus or position statement has been issued yet.

Purpose

To analyse the diagnostic work-up needed to reach a definite diagnosis in LDACM patients (pts).

Methods

All pts with a high clinical suspicion of ACM admitted at our institution were evaluated. Disease and familiar history, and both baseline ECG and cardiac ultrasound (US) were retrieved in all pts. Before invasive evaluation, all pts underwent cardiac magnetic resonance imaging (MRI) for morphology assessment and tissue characterization by late gadolinium enhancement (LGE). An invasive evaluation with an electrophysiological study (EPS) and an endo-cavitary electro-anatomical mapping (EAM) was then subsequently performed; EAM-guided endo-myocardial biopsy (EMB) was performed at physician discretion, for direct histological evaluation of myocardial substrate.

Results

30 ACM pts (53±6 y.o.; 66% male) were defined as LDACM; 22 (73%) pts presented unspecific ECG abnormalities, with 8 (27%) pts instead presenting negative t-waves in V4-V6. Cardiac US resulted unremarkable in 27 (90%) pts. Sustained ventricular arrhythmia with right bundle brunch block were experienced in 4 (14%) pts, while frequent premature ventricular beats with the same morphology in 10 (33%).

LDACM diagnosis was mainly suspected upon MRI evaluation: all 30 pts presented a late gadolinium enhancement (LGE) pattern revealing an isolate left ventricle fibro-fatty infiltration, with normal biventricular contractility (LV and RV ejection fraction 57±9% and 53±2%, respectively).

Right ventricular, left ventricular and biventricular endo-cavitary EAM was performed in 10 (33%), 11 (37%) and 9 (30%) pts respectively, revealing pathologically low unipolar voltages in 7 (23%) and both unipolar and bipolar low voltages in 15 (50%) pts. In 18 (60%) pts an EMB was performed, revealing in 15 (83%) a fibro-fatty infiltrate and a fibro-fatty infiltrated with a superimposed viral myocarditis in a single pt. Genetic testing was performed in 16 (53%) pts, of which 10 (33%) showed causative mutation of desmosomal genes.

If strictly adhering to the existing criteria, only 7 (23%) LDACM definite diagnosis would have been reached, even when using EMB and genetic testing.

LDACM EAM with late potentials

Conclusion

LDACM is an underestimated ACM subtype that require MRI evaluation and an invasive work-up for definite diagnosis. Although EMB and genetic testing being the most effective diagnostic tools currently at disposal adhering to existing criteria, a definite diagnosis could be reached only in a fraction of patient population. Existing diagnostic criteria should be revised, mainly to take in consideration EAM specific role and to properly define the LDACM entity.

2288Oxidized LDL/CD36/PPARg circuitry is a trigger of adipogenesis in arrhythmogenic cardiomyopathy

Background

Arrhythmogenic Cardiomyopathy (ACM) is a genetic condition hallmarked by ventricular fibro-fatty replacement and arrhythmias. Cardiac mesenchymal stromal cells (C-MSC) differentiate into adipocytes in ACM hearts, through the activation of PPARγ, caused by ACM mutations (e.g. PKP2). The clinical phenotype of ACM is variable for poorly understood reasons. The only recognized cofactor is physical exercise, which is known to increases oxidative stress. An accepted marker of exercise-induced oxidative stress is 13HODE, a component of oxLDL and direct activator of PPARγ. In macrophages, during foam cell formation, 13HODE creates a feed-forward loop increasing both PPARγ and the oxLDL receptor CD36, resulting in fat accumulation.

Purpose

To investigate oxLDL effects on ACM adipogenesis and to dissect the involved pathways.

Methods

We analyzed plasmas (n=42) and ventricular tissues (n=4) of ACM patients and matched healthy controls (HC). For in vitro experiments, ACM and HC C-MSC (n=10) have been used, while in vivo experiments have been conducted in heterozygous Pkp2 knock-out mice (Pkp2+/−; n=10).

Results

We observed higher plasma oxLDL in ACM patients compared to HC (ACM 246.70±55.89 vs HC 102.5±17.95ng/ml; p=0.019). oxLDL levels also discriminate between ACM patients with overt phenotype and their unaffected relatives carriers of the same causative mutations (p=0.03). We observed higher oxidative stress (MDA intensity 40.87±11.76 fold; p=0.015) and CD36 levels (14.72±2.10 fold; p=0.0007) in ACM ventricular tissue, compared to HC.

In basal conditions, ACM C-MSC showed greater oxidative stress (MDA intensity 8.83±2.78 fold p=0.017) and higher expression of PPARγ (1.47±0.14 fold; p=0.009) compared to HC C-MSC. The adipogenic stimulation led to a parallel increase of CD36 and lipid accumulation, mainly in ACM C-MSC (slopes statistically different p=0.016). OxLDL and 13HODE administration increased lipid accumulation in ACM C-MSC (ORO staining ACM vs ACM+oxLDL p=0.01; ACM vs ACM+13HODE p=0.014). On the contrary, the antioxidant N-Acetylcysteine (NAC) prevented lipid accumulation in ACM C-MSC (ORO staining ACM+13HODE vs ACM+13HODE+NAC p=0.0009). Through CD36 silencing of ACM C-MSC, we obtained a significantly lower lipid accumulation than non-silenced cells (ORO staining 0.35±0.10 fold; p=0.003).

Pkp2+/− mice do not spontaneously accumulate adipocytes in the heart, however Pkp2+/− C-MSC are more prone to lipid accumulation in vitro than WT cells (p=0.007). Accordingly, mice have low plasma oxLDL and cardiac oxidative stress. By increasing plasma cholesterol and oxidative stress through high fat diet, we observed fibro-fatty substitution in Pkp2+/− hearts (p=0.046).

Figure 1

Conclusions

These findings reveal a modulatory role of oxidized lipids in ACM adipogenesis at a cellular, tissue and clinical level, enlightening novel targets for pharmacological strategies to prevent adipogenic substitution and consequent ACM clinical phenotypes.

Acknowledgement/Funding

Telethon Foundation; Italian Ministry of Health

A new prediction model for left ventricular systolic function recovery after catheter ablation of atrial fibrillation in patients with heart failure and reduced ejection fraction, The ANTWOORD Study

Funding Acknowledgements

Type of funding sources: None.

Background

In patients with heart failure with reduced ejection fraction (HFrEF) and atrial fibrillation (AF), pulmonary vein isolation (PVI) improves left ventricular ejection fraction (LVEF), along with prognosis, in a variable percentage of patients.

Aim

To investigate the predictors of LVEF recovery after PVI and to develop a prediction model for individualized assessment.

Methods

We conducted an observational, retrospective, single-center study on 111 consecutive patients with AF and HFrEF undergoing PVI. Patients were divided into Responder vs. Non-Responder according to the "Universal definition of HF". Clinical predictors were evaluated by multivariate logistic regression analysis and cross-validation technique. Independent predictors were used to build an internally validated prediction model.

Results Responders (54%) had significantly shorter QRS duration and less dilated left atria. Persistent AF and absence of a known etiology more frequent among Responders. AF recurrence was non-significantly different between the two groups (p=0.2), although clinical AF burden was lower in Responders, after PVI (p&lt;0.001). Absence of known etiology, presence of persistent AF, left atrial volume index&lt;50ml/m2, and QRS&lt;120msec were independent predictors of LVEF recovery and composed the "Antwerp Score". Patients with Antwerp Score ≤1 had 90% likelihood of LVEF recovery, compared to 5% in patients with 3-6.

Conclusions Patients with wide QRS complex, known HF etiology, dilated left atria, and paroxysmal AF were less likely to recover LVEF after PVI. A new score system based on the above-mentioned parameters adequately predict LV function recovery after PVI. These results warrant confirmation and prospective validation.