Prognostic factors in hypertrophic cardiomyopathy in children: An MRI based study.

BACKGROUND: Clinical and prognostic role of cardiac magnetic resonance (CMR) in adult population with hypertrophic cardiomyopathy (HCM) have been largely assessed. We sought to investigate the role of CMR for predicting cardiovascular events in children with HCM. METHODS: CMR was performed in 116 patients with HCM (37 sarcomeric mutations, 31 other mutations, mean age 10.4 ± 4.3 yrs). CMR protocol included cine imaging for evaluation of morphology and function and late gadolinium enhancement (LGE). Hard cardiac events (sustained VT, resuscitated cardiac arrest, sudden cardiac death, end-stage heart failure, heart transplant and appropriate ICD intervention) were recorded through a median follow-up of 4 (1-7) years. RESULTS: During follow-up 21 heart cardiac events occurred. At maximal-rank statistic the optimal cut-point for LGE extent for predicting events was ≥2%. Syncope, non-sustained ventricular tachycardia (NSVT) and LGE extent ≥2% were independent predictors of events. At Harrel's C statistic combination of LGE extent ≥2% and syncope was the strongest model for predicting events. HR of patients with LGE extent ≥2% and no history of syncope was 3.6 (1.1-12.2) that increased to 37.6 (5.4-161) in those with LGE extent ≥2% and syncope. The median time dependent AUC of LGE extent (0.88, 95% CI 0.86-0.89) was significantly higher than that of syncope (0.63, 95% CI 0.61-0.66, p < 0.0001) and NSVT (0.52, 95% CI 0.50-0.53, p < 0.0001). CONCLUSIONS: In children with HCM, LGE and syncope were independent predictors of hard cardiac events at follow-up.

The Influence of Atrial Strain on Functional Capacity in Patients with the Fontan Circulation.

Speckle-tracking echocardiography has been used to assess atrial function. This analysis is feasible in univentricular hearts. The aim of this study was to characterize the relationship between atrial strain and functional capacity in the Fontan circulation. Apical four-chamber echocardiographic loops of 39 Fontan patients were reviewed. The dominant atrium was assessed for active (εact), conduit (εcon), and reservoir (εres) strain and εact/εres ratio. Cardiopulmonary exercise test was performed on the same day and oxygen uptake (VO2) at ventilatory threshold (VT) and peak VO2 were chosen as the dependent variables. Statistical analysis was performed using SPSS® version 23. Unpaired t test was used for binomial and continuous variable correlation; single and multivariable linear regression were used for continuous variable correlation. Statistical significance was defined as p value < 0.05. VO2 at VT as a percentage of predicted VO2 was 36.8% (SD 10.7). Peak VO2 was 64.7% (SD 18.9) of the predicted value. In univariate analysis, both were associated with age, atrioventricular regurgitation, ejection fraction, εres, εcon, and εact/εres. In multivariate regression, higher VO2 at VT and peak VO2 were associated with younger age (p = 0.003 and p = 0.001, respectively) and higher εcon (p = 0.026 and p = 0.020). Evaluation of heart function is difficult in the Fontan circulation, hindered by complex ventricular morphology and lack of normative data. VO2 provides a good surrogate. Atrial strain parameters are compromised in these patients and associated with VO2. Therefore, whenever possible, atrial strain should be measured as it may provide a new method of risk stratification.

Generation and characterization of a human iPS cell line from a patient-related control to study disease mechanisms associated with DAND5 p.R152H alteration.

A DAND5-control human iPSC line was generated from the urinary cells of a phenotypically normal donor. Exfoliated renal epithelial (RE) cells were collected and reprogrammed into iPSCs using Sendai virus reprogramming system. The pluripotency, in vitro differentiation potential, karyotype stability, and the transgene-free status of generated iPSC line were analyzed and confirmed. This cell line can be exploited as a control iPSC line to better understand the mechanisms involved in DAND5-associated cardiac disease.

Generation of human iPSC line from a patient with laterality defects and associated congenital heart anomalies carrying a DAND5 missense alteration.

A human iPSC line was generated from exfoliated renal epithelial (ERE) cells of a patient affected with Congenital Heart Disease (CHD) and Laterality Defects carrying tshe variant p.R152H in the DAND5 gene. The transgene-free iPSCs were generated with the human OSKM transcription factor using the Sendai-virus reprogramming system. The established iPSC line had the specific heterozygous alteration, a stable karyotype, expressed pluripotency markers and generated embryoid bodies that can differentiate towards the three germ layers in vitro. This iPSC line offers a useful resource to study the molecular mechanisms of cardiomyocyte proliferation, as well as for drug testing.

Functional study of DAND5 variant in patients with Congenital Heart Disease and laterality defects.

BACKGROUND: Perturbations on the Left-Right axis establishment lead to laterality defects, with frequently associated Congenital Heart Diseases (CHDs). Indeed, in the last decade, it has been reported that the etiology of isolated cases of CHDs or cases of laterality defects with associated CHDs is linked with variants of genes involved in the Nodal signaling pathway. METHODS: With this in mind, we analyzed a cohort of 38 unrelated patients with Congenital Heart Defects that can arise from initial perturbations in the formation of the Left-Right axis and 40 unrelated ethnically matched healthy individuals as a control population. Genomic DNA was extracted from buccal epithelial cells, and variants screening was performed by PCR and direct sequencing. A Nodal-dependent luciferase assay was conducted in order to determine the functional effect of the variant found. RESULTS: In this work, we report two patients with a DAND5 heterozygous non-synonymous variant (c.455G > A) in the functional domain of the DAND5 protein (p.R152H), a master regulator of Nodal signaling. Patient 1 presents left isomerism, ventricular septal defect with overriding aorta and pulmonary atresia, while patient 2 presents ventricular septal defect with overriding aorta, right ventricular hypertrophy and pulmonary atresia (a case of extreme tetralogy of Fallot phenotype). The functional analysis assay showed a significant decrease in the activity of this variant protein when compared to its wild-type counterpart. CONCLUSION: Altogether, our results provide new insight into the molecular mechanism of the laterality defects and related CHDs, priming for the first time DAND5 as one of multiple candidate determinants for CHDs in humans.

Doppler Flow Pattern and Arterial Stiffness in Patients with Aortic Coarctation.

Patients with aortic coarctation (CoAo) often have a diastolic flow in the descending aorta. The effect of arterial stiffness on CoAo flow pattern was described in vitro and with computer models. Study of Doppler flow patterns and arterial stiffness may provide helpful data to support the decision of CoAo treatment. Fifty studies were obtained in 31 patients (14 women, 21.5 ± 15.5 years). In 19 patients, studies were performed before and after percutaneous intervention. Systolic invasive gradients were measured (Sgrad). Doppler parameters included Doppler corrected gradient (Dgrad), diastolic velocity at end of T wave (DVT), end diastolic velocity (DVQ), systolic and diastolic half pressure times (SHPTc and DHPTc) and velocity runoff (VRc). In 19 patients, before intervention, arterial stiffness was assessed by measuring pulsed wave velocity (PWV) between right carotid and radial arteries. Sgrad showed correlation with Dgrad, DVT, DVQ, SHPTc, DHPTc and VRc (p < 0.01). Using multiple regression models, Sgrad variability was best explained by combining the variables Dgrad and DHPTc (R 2 = 0.766). A variable named DTail was obtained with DTail = 1 if DHPTc > 0. In the group with Sgrad below 30 mmHg, a negative correlation was found between DTail and PWV (p = 0.024), suggesting that low aortic stiffness contributes to persistent diastolic flow in the descending aorta. Doppler systolic and diastolic parameters correlated well with severity of CoAo. In mild to moderate CoAo, Doppler diastolic flow in the descending aorta was more likely in patients with lower arterial stiffness.

p-mTOR expression is associated with better prognosis in luminal breast carcinoma.

AIMS: Despite considerable interest in the PI3K/AKT/mTOR pathway in breast carcinomas (BC), published data reports contradictory results regarding the association of phosphorylated mammalian target of Rapamycin (p-mTOR) expression with clinico-pathological features and prognosis in BC. Here, we evaluate the main clinico-pathological associations with p-mTOR expression in BC, with focus on the different molecular subtypes. METHODS: In this retrospective study, 331 BC patients were included in final analysis. Outcome measures included disease-free survival (DFS) and overall survival (OS) times. Baseline data and outcome measures were compared between immunohistochemical p-mTOR expressing and non-expressing BCs. Subgroup analysis was performed to assess the effect of p-mTOR expression in the outcome for each BC molecular subtype. RESULTS: 43.8% of the tumours were positive for p-mTOR, with a significant correlation between p-mTOR expression with smaller (<2 cm) (p=0.021) and lower-grade tumours (p<0.001). Expression of p-mTOR was also associated with longer DFS (HR of 0.32, p<0.001) and OS (HR of 0.20, p<0.001). In a multivariable analysis, the HR remained significant with minimal change (HR=0.26, p=0.002 for OS; HR=0.40, p=0.002 for DFS). In subgroup analysis, luminal p-mTOR-expressing tumours demonstrated longer DFS and OS (HR 0.33, p=0.003; HR 0.20, p=0.003, respectively) independently of size, grade, lymph node status and Her-2 overexpression. CONCLUSIONS: p-mTOR expression is associated with smaller, lower-grade and with luminal BC. In multivariable analysis, p-mTOR expression was associated with longer DFS and OS, independently of the size, grade and lymph node status, especially in luminal BCs.