Pathogenic truncating filamin C mutations presenting as acute myocarditis: a case series with insights from cardiac magnetic resonance and histological analysis

Background

The exact mechanisms underlying the pathogenesis of myocarditis are not always understood, but there is emerging evidence to suggest that genetic factors may play a significant role.

Case summary

Herein, we present six cases in which clinical, biochemical, and cardiovascular magnetic resonance data were consistent with myocarditis, and genetic testing subsequently revealed pathogenic filamin C (FLNC) mutations. Three patients presented with ventricular arrhythmias, two with severe biventricular dysfunction, and two suffered sudden cardiac arrest. Three received an implantable cardioverter defibrillator, and one underwent heart transplantation. Cascade testing was useful in identifying other relatives with FLNC mutation. We also present relevant histology results of myocardial specimens showing the presence of lymphocytic infiltration and inflammation, further supporting the potential association between FLNC mutations and a myocarditis phenotype.

Discussion

Genetic testing of affected individuals for FLNC mutations and cascade screening in the setting of acute myocarditis may be considered in selected clinical context, such as in acute myocarditis accompanied by severe left ventricular systolic dysfunction, biventricular failure, significant ventricular arrhythmias, or right ventricular involvement.

The prognostic impact of right ventricular-pulmonary arterial coupling in heart failure: a systematic review and meta-analysis

The echocardiographic tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) ratio is a non-invasive surrogate of right ventricular-pulmonary arterial (RV-PA) coupling which corresponds well with the respective invasively derived index. Recently, a wealth of observational data has arisen, outlining its prognostic value in heart failure (HF) patients. To systematically appraise and quantitatively synthesize the evidence of the prognostic value of TAPSE/PASP ratio in left-sided HF regardless of etiology or left ventricular ejection fraction. A systematic literature review was conducted in electronic databases to identify studies reporting the association of TAPSE/PASP ratio with outcomes in patients with HF and, when appropriate, a random-effects meta-analysis was conducted to quantify the unadjusted and adjusted hazard ratios [(a)HRs] for all-cause death and the composite outcome of all-cause death or HF hospitalization. Eighteen studies were deemed eligible encompassing 8,699 HF patients. The applied cut-off value for RV-PA uncoupling varied substantially from 0.27 to 0.58 mm/mmHg, and in most studies values lower than the applied cutoff conveyed dismal prognosis. Eleven studies reported appropriate data for meta-analysis. TAPSE/PASP reduction by 1 mm/mmHg was independently associated with all-cause death (pooled aHR=1.32 [1.06-1.65]; p=0.01; I2=56%) and the composite outcome (pooled aHR=3.48 [1.67-7.25]; p<0.001; I2=0%). When a TAPSE/PASP cutoff value of 0.36 mm/mmHg was applied it yielded independent association with all-cause death (pooled aHR=2.84 [2.22-3.64]; p<0.001; I2=82%). RV-PA coupling assessed by echocardiographic TAPSE/PASP ratio appears to be an independent outcome predictor for HF patients.

Periostin is overexpressed, correlated with fibrosis and differs among grades of cardiomyocyte hypertrophy in myectomy tissue of patients with hypertrophic cardiomyopathy

Periostin, a secreted matricellular protein, has been implicated in cardiac extracellular matrix remodeling and fibrosis. Evidence suggest that periostin stimulates cardiomyocyte hypertrophy. The current study aims to investigate the extent of periostin expression in patients with advanced Hypertrophic Cardiomyopathy (HCM) and its correlation with fibrosis and hallmark histopathological features of the disease. Interventricular septal tissue from thirty-nine HCM patients who underwent myectomy and five controls who died from non-cardiac causes was obtained. Staining with Masson's Trichrome and immunohistochemistry were used to localize fibrosis and periostin respectively. The extent of fibrosis and the expression of periostin were defined as the stained percentage of total tissue area using digital pathology software. Periostin expression was higher in HCM patients compared to controls (p<0.0001), positively correlated with the extent of fibrosis (r = 0.82, p<0.001), positively correlated with maximal interventricular septal thickness (Rho = 0.33, p = 0.04) and negatively correlated with LVEF (r = -0.416, p = 0.009). Periostin was approximately co-localized with fibrosis. Mean periostin expression was lower in patients with mild grade cardiomyocyte hypertrophy compared to those with moderate grade (p = 0.049) and lower in patients with mild grade replacement fibrosis compared to moderate grade (p = 0.036). In conclusion, periostin is overexpressed in advanced HCM, correlated with fibrosis and possibly related to cardiomyocyte hypertrophy.

Prevalence, characteristics, and natural history of apical phenotype in a large cohort of patients with hypertrophic cardiomyopathy

BACKGROUND

Apical hypertrophic cardiomyopathy (ApHCM) is a variant of hypertrophic cardiomyopathy (HCM) with distinct imaging and clinical characteristics. Data on the prognosis of this HCM subgroup appear conflicting. Our study aims to clarify the natural history of ApHCM and identify predictors of outcomes.

MATERIALS AND METHODS

A total of 856 patients with HCM were retrospectively examined. ApHCM was defined as asymmetric left ventricular hypertrophy confined predominantly at the apex, either isolated (pure ApHCM type) or with co-existent hypertrophy of the interventricular septum (mixed ApHCM). Echocardiographic, clinical, and survival data were compared between individuals with ApHCM and non-ApHCM.

RESULTS

A total of 143 (16.7%) patients were diagnosed with ApHCM. Compared with non-ApHCM, subjects with apical HCM were diagnosed at an older age and had better echocardiographic indices and more comorbidities at baseline. Apical aneurysms were more prevalent among the ApHCM phenotype (6.3% vs. 1.7%, p = 0.003). During a mean follow-up of 6 ± 3 years, ApHCM was characterized by lower all-cause, cardiovascular, heart failure-related mortality, and ventricular arrhythmic events compared with non-ApHCM. Multivariate analysis identified atrial fibrillation and HCM risk-sudden cardiac death (SCD) as independent predictors of the composite outcome of overall mortality and hospitalizations for cardiovascular reasons (hazard ratio [HR] 4.3, 95% confidence interval [CI] 1.9-9.5 for atrial fibrillation and HR 1.2, 95% CI 1.02-1.3 for HCM risk-SCD) in ApHCM.

CONCLUSIONS

ApHCM exhibited a lower rate of all-cause mortality and arrhythmic events in the middle-aged population of patients with HCM. Atrial fibrillation and HCM risk-sudden cardiac death were independent predictors of a composite of overall mortality and cardiovascular hospitalizations among those with ApHCM.

Apical Hypertrophic Cardiomyopathy: Diagnosis, Natural History, and Management

Apical hypertrophic cardiomyopathy (ApHCM) represents a rare variant of hypertrophic cardiomyopathy (HCM) with distinct phenotypic characteristics. The prevalence of this variant varies according to each study's geographic region. The leading imaging modality for the diagnosis of ApHCM is echocardiography. Cardiac magnetic resonance, however, is the gold standard for ApHCM diagnosis in case of poor acoustic windows or equivocal echocardiographic findings but also in cases of suspected apical aneurysms. The prognosis of ApHCM was reported to be relatively benign, although more recent studies seem to contradict this, demonstrating similar incidence of adverse events compared with the general HCM population. The aim of this review is to summarize the available evidence for the diagnosis of ApHCM, highlight distinctions in comparison to more frequent forms of HCM with regards to its natural history, prognosis, and management strategies.

Left Atrial Myopathy is Associated With Exercise Incapacity and Ventilatory Inefficiency in Hypertrophic Cardiomyopathy

BACKGROUND

Left atrial (LA) myopathy is an established component of hypertrophic cardiomyopathy (HCM); however, the data about its association with exercise incapacity or ventilatory inefficiency that may be seen in HCM patients are limited. This study aimed to explore the association between LA myopathy, evaluated by echocardiography LA strain, and exercise capacity and ventilatory efficiency, evaluated by cardiopulmonary exercise testing (CPET), in HCM patients.

METHODS

This study included 241 consecutive HCM patients (aged 51.2±15.7 years 67.2% male) in sinus rhythm who underwent CPET and transthoracic echocardiography at the same visit. Exercise incapacity (maximal/predicted oxygen consumption [%peakVO₂] <80%) and ventilatory inefficiency (ventilation/carbon dioxide output [VE/VCO₂] slope >34) were assessed by CPET. Left atrial myopathy was examined by speckle-tracking myocardial deformation parameters: LA reservoir, conduit and booster strain.

RESULTS

All three LA strain values were univariate predictors of exercise capacity and ventilatory efficiency. Among them, LA reservoir strain had the higher r correlation coefficient for predicting both %peakVO₂ and VE/VCO₂ slope. Left atrial reservoir strain, presence of angina and family history of HCM were independent predictors of exercise capacity. Left atrial reservoir strain, male gender and non-sustained ventricular tachycardia were independent predictors of ventilatory efficiency. Left atrial reservoir strain was a significant predictor of %peakVO₂<80% with an optimal cut-off value of 27% (sensitivity 87% and specificity 31%) and VE/VCO₂>34 with an optimal cut-off value of 18% (sensitivity 71% and specificity 83%).

CONCLUSION

Left atrial myopathy, as reflected by the LA strain values, was associated with exercise incapacity and ventilatory inefficiency in HCM individuals. Left atrial reservoir strain was the only common independent predictor of %peakVO₂ and VE/VCO₂ slope.

Wild-Type Transthyretin Amyloid Cardiomyopathy: The Gordian-Knot of Novel Therapeutic Regimens

Wild-type TTR amyloidosis (wtATTR) represents a disease difficult to diagnose with poor prognosis. Increased clinical suspicion is key, allowing for timely diagnosis. Until recently, only off-label therapies were available but recent introduction of disease specific therapy has shown potential to alter the natural history of the disease. Tafamidis, the only currently approved drug for the therapy of wtATTR, provided significantly better survival and quality of life. However, not all subgroups of patients derived equal benefit. This, along with the increased cost of treatment raised question on whether treatment should be invariably administered through the wtATTR population. This review aims to summarize current evidence on the natural history and staging systems for wtATTR, as well as available treatment options. Special consideration is given to the selection process of patients who would be expected to gain maximum benefit from tafamidis treatment, based on an ethical and cost-effective point of view.

Cardiac Outcomes in Adults With Mitochondrial Diseases

BACKGROUND

Patients with mitochondrial diseases are at risk of heart failure (HF) and arrhythmic major adverse cardiac events (MACE).

OBJECTIVES

We developed prediction models to estimate the risk of HF and arrhythmic MACE in this population.

METHODS

We determined the incidence and searched for predictors of HF and arrhythmic MACE using Cox regression in 600 adult patients from a multicenter registry with genetically confirmed mitochondrial diseases.

RESULTS

Over a median follow-up time of 6.67 years, 29 patients (4.9%) reached the HF endpoint, including 19 hospitalizations for nonterminal HF, 2 cardiac transplantations, and 8 deaths from HF. Thirty others (5.1%) reached the arrhythmic MACE, including 21 with third-degree or type II second-degree atrioventricular blocks, 4 with sinus node dysfunction, and 5 sudden cardiac deaths. Predictors of HF were the m.3243A>G variant (HR: 4.3; 95% CI: 1.8-10.1), conduction defects (HR: 3.0; 95% CI: 1.3-6.9), left ventricular (LV) hypertrophy (HR: 2.6; 95% CI: 1.1-5.8), LV ejection fraction <50% (HR: 10.2; 95% CI: 4.6-22.3), and premature ventricular beats (HR: 4.1; 95% CI: 1.7-9.9). Independent predictors for arrhythmia were single, large-scale mtDNA deletions (HR: 4.3; 95% CI: 1.7-10.4), conduction defects (HR: 6.8; 95% CI: 3.0-15.4), and LV ejection fraction <50% (HR: 2.7; 95% CI: 1.1-7.1). C-indexes of the Cox regression models were 0.91 (95% CI: 0.88-0.95) and 0.80 (95% CI: 0.70-0.90) for the HF and arrhythmic MACE, respectively.

CONCLUSIONS

We developed the first prediction models for HF and arrhythmic MACE in patients with mitochondrial diseases using genetic variant type and simple cardiac assessments.

A novel quantitative method for assessing the therapeutic response to Tafamidis therapy in patients with cardiac TTR amyloidosis. A preliminary report

OBJECTIVE

Cardiomyopathy is a common manifestation of transthyretin amyloidosis (ATTR), leading to heart failure, associated with high morbidity and mortality. The aim of this study was to investigate the effect of Tafamidis treatment by means of cardiac radiotracer uptake on myocardial scintigraphy.

SUBJECTS AND METHODS

Five male patients, mean age 76.2 years, with wild-type ATTR were included in the protocol. Total body scanning using technetium-99m-3,3-diphosphono-1,2-propanodicarboxylic acid (^99mTc-DPD) (in four patients) and technetium-99m-hydroxymethylene diphosphonate (^99mTc-HMDP) (in one) was performed pre- and one year post-Tafamidis therapy. A novel quantitation method for assessing radiotracer cardiac uptake was employed. The geometric mean was computed for both cardiac and thigh region of interest (ROI) and the heart-to-thigh (HtT) ratio was assessed by dividing the corresponding geometric mean counts.

RESULTS

Heart-to-thigh ratio was improved (decreased) in four of the patients receiving Tafamidis, in keeping with lower uptake to the cardiac region. These patients also demonstrated a relatively favorable clinical response to Tafamidis. The patient evaluated by ^99mTc-HMDP exhibited minimal HtT ratio reduction and stable clinical and echocardiographic characteristics.

CONCLUSION

Sequential HtT ratio measurements could potentially identify patients with a favorable response to Tafamidis treatment at earlier stages, compared to other imaging modalities or serological biomarkers.

Left atrial myopathy is associated with exercise capacity and ventilatory efficiency in hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

Data about the predictive value of left atrial (LA) myopathy for exercise capacity and ventilatory efficiency in patients with hypertrophic cardiomyopathy (HCM) are limited.

Purpose

The aim of this study was to evaluate the association of LA myopathy, evaluated by echocardiography LA strain, with exercise capacity and ventilatory efficiency, evaluated by cardiopulmonary exercise testing (CPET), in HCM patients.

Methods

In total, 241 consecutive HCM patients (51 ± 16 years old; 67.2% male) on sinus rhythm that underwent CPET and transthoracic echocardiography at the same visit were studied. Exercise capacity (maximal oxygen consumption/predicted [%peakVO2]) and ventilatory efficiency (ventilation/carbon dioxide output [VE/VCO2] slope) were assessed by CPET. LA myopathy was examined by speckle tracking myocardial deformation parameters: LA reservoir, conduit and booster strain.

Results

All the three LA strain values were univariate predictors of exercise capacity and ventilatory efficiency. Among them, LA reservoir strain had the higher r correlation coefficient for predicting both %peakVO2 and VE/VCO2 slope and was included in multivariable analyses. LA reservoir strain, male gender and E/E’ ratio were independent predictors of exercise capacity. LA reservoir strain, male gender, non-sustained ventricular tachycardia and LA volume index were independent predictors of ventilatory efficiency (Table).

Conclusion

LA myopathy, as reflected by the LA strain values, was associated with exercise capacity and ventilatory efficiency in HCM individuals. LA reservoir strain was the only common independent predictor for %peakVO2 and VE/VCO2 slope. Abstract Table

Left atrial myopathy and mitral regurgitation in hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

Recent studies have shown that mitral regurgitation (MR) represents a major determinant of left atrial (LA) function in patients with heart failure with preserved ejection fraction. The role of MR in determining LA myopathy in hypertrophic cardiomyopathy (HCM) is unknown.

Purpose

The aim of this study was to examine the association of MR with LA myopathy, assessed by LA strain in HCM patients.

Methods

 In total 250 consecutive patients (mean age 51 ± 16years, 67.2% male) with an established diagnosis of HCM and with sinus rhythm at index echocardiography evaluation were included. LA reservoir, conduit and booster strain were analyzed, besides LA size, left ventricular (LV) systolic and diastolic function. The predictors of LA strain values were identified with linear regression analysis.

Results

More than mild MR was a significant univariate predictor of all the three LA strain values. In multivariate linear regression analysis, independent predictors of LA reservoir strain were more than mild MR (r= -0.23), LV global longitudinal strain (r= -0.49), LA volume index (r= -0.27) and patient age (r= -0.22). More than mild MR was also an independent determinant of LA conduit (r=-0.17) and booster strain (r=-0.12) (Table 1). In patients with LA volume index &lt;34ml/m2 more than mild MR was an independent predictor of LA reservoir (r= -0.32) and conduit strain (r= -0.27), but not LA booster strain (Table 2).

Conclusion

The severity of MR is associated with LA myopathy with independently of the LV diastolic and systolic function and LA size. Abstract Table 1  Abstract Table 2

Deciphering hypertrophic cardiomyopathy with electrocardiography

The comprehensive assessment of patients with hypertrophic cardiomyopathy is a complex process, with each step concurrently focusing on confirmation of the diagnosis, differentiation between sarcomeric and non-sarcomeric disease (phenocopy), and prognostication. Novel modalities such as genetic testing and advanced imaging have allowed for substantial advancements in the understanding of this condition and facilitate patient management. However, their availability is at present not universal, and interpretation requires a high level of expertise. In this setting, electrocardiography, a fast and widely available method, still retains a significant role in everyday clinical assessment of this population. In our review, we follow a stepwise approach for the interpretation of each electrocardiographic segment, discussing clinical implications of electrocardiographic patterns in sarcomeric disease, their value in the differential diagnosis from phenocopies, and impact on patient management. Outlining the substantial amount of information to be obtained from a simple tracing, we exhibit how electrocardiography is likely to remain an integral diagnostic tool in the future as well.

A Normal Electrocardiogram Does Not Exclude Infra-Hisian Conduction Disease in Patients With Myotonic Dystrophy Type 1

OBJECTIVES

This study aimed to identify electrocardiographic (ECG) predictors of a prolonged His-ventricular (HV) interval in patients with type 1 myotonic dystrophy (DM1).

BACKGROUND

Patients with DM1 have an increased risk of sudden cardiac death. The presence of His-Purkinje system disease/prolonged HV interval (≥70 ms) is associated with a higher risk of potentially life-threatening bradyarrhythmic events.

METHODS

Electrophysiology studies (EPSs) were performed in all DM1 patients referred to 2 tertiary centers for routine cardiac assessment. In a subgroup of patients, the EPS was repeated at varying intervals.

RESULTS

A total of 154 patients (mean age: 43.7 ± 13.3; 58.1% male) underwent 202 diagnostic EPSs. HV ≥70 ms was found on 58 EPSs (28.7%); 9 of 59 patients (15.2%) with PR <200 ms and QRS interval <110 ms on baseline ECG had an HV ≥70 ms on EPS. Among those with PR ≥200 ms and/or QRS interval ≥100 ms, only 33.9% had an HV ≥70 ms on EPS. There were 38 patients who underwent repeated EPS, in which 28.8% demonstrated a prolongation of the HV interval overall compared with baseline. QRS duration demonstrated the most powerful discriminative capacity for HV ≥70 ms (area under the receiver operating characteristic curve: 0.76; 95% confidence interval [CI]: 0.68 to 0.84; p < 0.001). On multivariate analysis, QRS interval ≥112 ms had the highest predictive value for HV ≥70 ms (odds ratio: 7.94; 95% CI: 3.85 to 16.37.

CONCLUSIONS

ECG parameters have a poor predictive value for infra-Hisian conduction block in DM1 patients. QRS and PR intervals are normal in up to 15.2% of DM1 patients with prolonged HV, and 66.1% of those with PR ≥200 ms and/or QRS ≥100 ms do not have advanced His-Purkinje conduction system disease on EPS. Electrophysiology testing should be a mandatory part of screening for all patients to guide prophylactic pacemaker implantation.

A simple algorithm for a clinical step-by-step approach in the management of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease with an autosomal dominant pattern and a reported prevalence of about 0.2%. In this review, we present a simple algorithm for the management of first diagnosed HCM patients. Initially, the clinical examination, medical and detailed family history and the ECG are essential. The etiological diagnosis of left ventricular hypertrophy is important in order to differentiate HCM due to sarcomeric genes mutation from other phenocopies, such as cardiac amyloidosis. The next step consists of the cardiovascular imaging and ambulatory electrocardiography. Cardiopulmonary exercise testing may also be considered if available. All of the above provide evidence for the critical step of the risk stratification of patients for sudden cardiac death. The therapeutic strategy, with respect to obstructive and nonobstructive disease, arrhythmias and end-stage HCM is also described.

Myocardial work analysis in screening of familial dilated cardiomyopathy

Introduction

Early detection of affected family relatives of patients with dilated cardiomyopathy (DCM) is essential in order to guide follow up, outcomes and initiate early treatment. Myocardial work analysis is a novel method which integrated strain imaging and blood pressure and has the potential to identify patients with subclinical disease.

Purpose

We analysed myocardial work in family relatives of DCM patients with positive genotype but negative phenotype in order to identify whether myocardial work can identify early changes.

Methods

Seventy-four family relatives of DCM patients attending for screening were examined. All individuals were asymptomatic with either positive (45/74, G+) or negative (29/74, G-) genotype and no echocardiographic evidence of left ventricular dilatation or systolic impairment. Non-invasive myocardial work analysis using two-dimensional (2D) speckle tracking echocardiography was analysed. Global longitudinal strain (GLS) was measured by the same vendor specific software used for myocardial work analysis. Left ventricular (LV) ejection fraction (EF) was measured with the Simpson's biplane method. The peak systolic arm cuff blood pressure (BP) measurement at the time of echocardiography was used for the myocardial work study.

Results

In total we included 74 individuals (37±15 years old, 50.7% women) with mean systolic and diastolic BP of 121.3±14 and 73.2±10 mmHg respectively, mean EF was 58±5% and mean GLS at 18.4±2.5%.

G+ individuals had pathogenic and very likely pathogenic mutations in 8 different genes (TTN, BAG3, DSP, FLNC, LMNA, DMD, RBM20, TPM1). There was no difference in age, systemic hypertension, diabetes or medical treatment between the 2 groups.

No significant difference was found among G+ and G- individuals in mean systolic and diastolic BP (121.2±14.7 vs 121.2±15.2 mmHg), mean EF (57.3±5 vs 59.1±4%), GLS (−18.2±1.5 vs −18.6±2.9%), mean global work index (1818±403 vs 1928±295 mmHg%) and global constructive work (2192±464 vs 2260±318 mmHg%).

However, we found significant reduction of the global work efficiency (GWE) with a GWE of 94.4±2.7% in the G+ versus 95.9±1.6% in the G- individuals (p 0.02). Moreover, the global wasted work (GWW) was increased in the G+ with a GWW of 111±58 mmHg% versus 82±41 mmHg% in the G- individuals (p 0.03).

Conclusion

DCM gene carriers show, early on, decreased myocardial work efficiency and increased wasted work compared to unaffected family members, which appears to be earlier than other parameters such as EF and GLS. Myocardial work analysis could potentially recognize individuals showing early cardiac involvement and guide closer follow up and early initiation of treatment.

Funding Acknowledgement

Type of funding source: None

5164New risk prediction score for life-threatening ventricular tachyarrhythmias in laminopathies

Background

An accurate estimation of the risk of life-threatening (LT) ventricular tachyarrhythmia (VTA) in patients with LMNA mutations is crucial to select candidates for implantable cardioverter defibrillator (ICD) implantation.

Methods

We included 839 adult patients with LMNA mutations, including 660 from a French nationwide registry in the development sample, and 179 from other countries, referred to 5 tertiary centers for cardiomyopathies, in the validation sample. LTVTA was defined as a) sudden cardiac death or b) ICD-treated or hemodynamically unstable VTA. The prognostic model was derived using Fine-Gray's regression model. The net reclassification was compared with current clinical practice guidelines. The results are presented as means (standard deviation) or medians [interquartile range].

Results

We included 444 patients 40.6 (14.1) years of age in the derivation sample and 145 patients 38.2 (15.0) years in the validation sample, of whom 86 (19.3%) and 34 (23.4%) suffered LTVTA over 3.6 [1.0–7.2] and 5.1 [2.0–9.3] years of follow-up, respectively. Predictors of LTVTA in the derivation sample were: male sex, non-missense LMNA mutation, 1st degree and higher atrioventricular block, non-sustained ventricular tachycardia, and left ventricular ejection fraction. In the derivation sample, C-index (95% CI) of the model was 0.776 (0.711–0.842). In the external validation sample, the C-index was 0.800 (0.642–0.959) and calibration slope 1.082 (95% CI, 0.643–1.522). A 5-year estimated risk threshold ≥7% predicted 96.2% of LTVTA and net reclassified 28.8% of patients with LTVTA compared with the guidelines-based approach.

Conclusions

Compared to the current standard of care, this risk prediction model for LTVTA in laminopathies facilitated significantly the choice of ICD candidates.

Acknowledgement/Funding

AFM Téléthon

Development and Validation of a New Risk Prediction Score for Life-Threatening Ventricular Tachyarrhythmias in Laminopathies

BACKGROUND

An accurate estimation of the risk of life-threatening (LT) ventricular tachyarrhythmia (VTA) in patients with LMNA mutations is crucial to select candidates for implantable cardioverter-defibrillator implantation.

METHODS

We included 839 adult patients with LMNA mutations, including 660 from a French nationwide registry in the development sample, and 179 from other countries, referred to 5 tertiary centers for cardiomyopathies, in the validation sample. LTVTA was defined as (1) sudden cardiac death or (2) implantable cardioverter defibrillator-treated or hemodynamically unstable VTA. The prognostic model was derived using the Fine-Gray regression model. The net reclassification was compared with current clinical practice guidelines. The results are presented as means (SD) or medians [interquartile range].

RESULTS

We included 444 patients, 40.6 (14.1) years of age, in the derivation sample and 145 patients, 38.2 (15.0) years, in the validation sample, of whom 86 (19.3%) and 34 (23.4%) experienced LTVTA over 3.6 [1.0-7.2] and 5.1 [2.0-9.3] years of follow-up, respectively. Predictors of LTVTA in the derivation sample were: male sex, nonmissense LMNA mutation, first degree and higher atrioventricular block, nonsustained ventricular tachycardia, and left ventricular ejection fraction (https://lmna-risk-vta.fr). In the derivation sample, C-index (95% CI) of the model was 0.776 (0.711-0.842), and the calibration slope 0.827. In the external validation sample, the C-index was 0.800 (0.642-0.959), and the calibration slope was 1.082 (95% CI, 0.643-1.522). A 5-year estimated risk threshold ≥7% predicted 96.2% of LTVTA and net reclassified 28.8% of patients with LTVTA in comparison with the guidelines-based approach.

CONCLUSIONS

In comparison with the current standard of care, this risk prediction model for LTVTA in laminopathies significantly facilitated the choice of candidates for implantable cardioverter defibrillators.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT03058185.

Multimodal Treatment of Homozygous Familial Hypercholesterolemia

Background:

Familial Hypercholesterolemia (FH) is an autosomal-dominant genetic disease, associated with premature atherosclerotic Cardiovascular Disease (CVD), especially in its homozygous type (HoFH).

Objective:

The aim of this review is to discuss the safety and efficacy of combination treatments (procedures and drugs) for HoFH.

Results:

Historically, liver transplantation was used first; however, it is currently considered only as a last resort for some patients. In the mid 70’s, LDL aphaeresis was introduced and remains up today the treatment of choice for patients of any age, despite its significant cost. The use of Ezetimibe results in additive 15-20% reductions in LDL-C regardless of the therapeutic approach, while statins are modestly effective in patients with class 4 or 5 mutations, in which LDL Receptors (LDLR) are present. One of the novel drugs for HoFH is Lomitapide, which is a highly effective oral agent, but is also exceedingly expensive ($350, 000/year). Mipomersen is administered every week subcutaneously, is also effective but has been approved only in the US mainly due to injection site reactions up to 80%. Both Lomitapide (mainly) and Mipomersen have been found to promote fat accumulation in the liver, resulting in subsequent serum transaminases elevations. PCSK9 inhibitors are effective in those with partial LDLR presence and function by reducing frequency of LDL apheresis, improve cost effectiveness of treatment.

Conclusion:

Pediatric and adult HoFH treatment needs combination of procedures and drugs. The main treatment is LDL-C apheresis aided by ezetimibe and PCSK9 inhibitors. Lomitapide needs caution, and liver transplantation is an alternative as the last resort.

Hypertrophic cardiomyopathy in 2013: Current speculations and future perspectives

Hypertrophic cardiomyopathy (HCM), the most variable cardiac disease in terms of phenotypic presentation and clinical outcome, represents the most common inherited cardiomyopathic process with an autosomal dominant trait of inheritance. To date, more than 1400 mutations of myofilament proteins associated with the disease have been identified, most of them “private” ones. This striking allelic and locus heterogeneity of the disease certainly complicates the establishment of phenotype-genotype correlations. Additionally, topics pertaining to patients’ everyday lives, such as sudden cardiac death (SCD) risk stratification and prevention, along with disease prognosis, are grossly related to the genetic variation of HCM. This review incorporates contemporary research findings and addresses major aspects of HCM, including preclinical diagnosis, genetic analysis, left ventricular outflow tract obstruction and SCD. More specifically, the spectrum of genetic analysis, the selection of the best method for obstruction alleviation and the need for a unique and accurate factor for SCD risk stratification are only some of the controversial HCM issues discussed. Additionally, future perspectives concerning HCM and myocardial ischemia, as well as atrial fibrillation, are discussed. Rather than enumerating clinical studies and guidelines, challenging problems concerning the disease are critically appraised by this review, highlighting current speculations and recommending future directions.

The pathophysiological basis of renal nerve ablation for the treatment of hypertension

Renal sympathetic innervation plays an important role in blood pressure regulation. Gradual activation of renal sympathetic efferent nerves enhances renin release, promotes sodium and water re-absorption, and reduces renal blood flow and glomerular filtration rate. On the other hand, activation of renal afferent sympathetic nerves induced by renal injury results in central sympathetic activation. This reciprocal relationship between the kidneys and the brain is involved in the pathogenesis of hypertension and other disease conditions characterized by sympathetic overactivity. Renal sympathetic nerve ablation has been recently introduced for the treatment of resistant hypertension. This review aims to provide the pathophysiological basis of renal nerve ablation for the attenuation of sympathetic overactivity.

Clinical characteristics and natural history of hypertrophic cardiomyopathy with midventricular obstruction

BACKGROUND

The prevalence, clinical characteristics and natural history of patients with hypertrophic cardiomyopathy (HCM) and midventricular obstruction (MVO) have not been adequately studied.

METHODS AND RESULTS

A single-center cohort consisting of 423 patients (mean age, 49.3±17.2 years; 66.2% male) was thoroughly followed up for a median of 84 months (7 years; range, 6-480 months). MVO, characterized by the echocardiographic appearance of midventricular muscular apposition with a simultaneous mid-cavitary gradient ≥30mmHg, was identified in 34 patients (8%). Patients with MVO tended to be more symptomatic during their initial evaluation (>90% presented with NYHA class ≥II) compared to the rest of the HCM cohort. Apical aneurysm formation was identified in more than one-fourth of patients with MVO (26.5%), being a characteristic of the group. On multivariate Cox regression hazard analysis, presence of MVO strongly predicted progression to end-stage (burnt out) HCM and related heart failure (HF) deaths (hazard ratio, [HR], 2.62; 95% confidence interval [CI]: 1.2-8.8; P=0.047), as well as sudden death and associated lethal arrhythmic events (HR, 3.3; 95% CI: 1.26-8.85; P=0.016).

CONCLUSIONS

MVO is a distinct phenotype of HCM associated with unfavorable prognosis in terms of end-stage HCM, sudden death and lethal arrhythmic events. The high adverse outcome rate necessitates early recognition of MVO and appropriate therapeutic interventions.

Serum Uric Acid as an Independent Predictor of Early Death After Acute Stroke

BACKGROUND

The prognostic significance of uric acid (UA) levels in acute stroke is unclear, so the objective of this study was to determine the association between levels of serum UA (SUA) and mortality in acute stroke.

METHODS AND RESULTS

Consecutive patients (n=435) presenting with ischemic stroke and intracerebral hemorrhage were included in the study. The length of stay in hospital and the occurrence of death were recorded. On univariate analysis, the occurrence of death was associated with older age, smoking, presence of congestive heart failure or atrial fibrillation, absence of hyperlipidemia, and intracerebral hemorrhage as the index event. Furthermore, glucose, urea, creatinine and SUA at admission were significantly higher in patients who died, whereas total and high-density-lipoprotein cholesterol were significantly lower. On multiple logistic regression analysis, the independent relationship between higher SUA levels and death was confirmed (odds ratio (OR), 1.37; 95%confidence interval (CI), 1.13-1.67; p=0.001). The only other variables independently associated with the occurrence of death were urea concentration and presence of atrial fibrillation. If urate was >7.8 mg/dl (0.47 mmol/L), then there would be a high probability of early death (87%).

CONCLUSIONS

Elevated levels of SUA are independently associated with an increased risk of early death in acute stroke.