Protocolo de actuación en las cardiopatías familiares: síntesis de recomendaciones y algoritmos de actuación

Penetrance of Dilated Cardiomyopathy in Genotype-Positive Relatives

BACKGROUND

Disease penetrance in genotype-positive (G+) relatives of families with dilated cardiomyopathy (DCM) and the characteristics associated with DCM onset in these individuals are unknown.

OBJECTIVES

This study sought to determine the penetrance of new DCM diagnosis in G+ relatives and to identify factors associated with DCM development.

METHODS

The authors evaluated 779 G+ patients (age 35.8 ± 17.3 years; 459 [59%] females; 367 [47%] with variants in TTN) without DCM followed at 25 Spanish centers.

RESULTS

After a median follow-up of 37.1 months (Q1-Q3: 16.3-63.8 months), 85 individuals (10.9%) developed DCM (incidence rate of 2.9 per 100 person-years; 95% CI: 2.3-3.5 per 100 person-years). DCM penetrance and age at DCM onset was different according to underlying gene group (log-rank P = 0.015 and P <0.01, respectively). In a multivariable model excluding CMR parameters, independent predictors of DCM development were: older age (HR per 1-year increase: 1.02; 95% CI: 1.0-1.04), an abnormal electrocardiogram (HR: 2.13; 95% CI: 1.38-3.29); presence of variants in motor sarcomeric genes (HR: 1.92; 95% CI: 1.05-3.50); lower left ventricular ejection fraction (HR per 1% increase: 0.86; 95% CI: 0.82-0.90) and larger left ventricular end-diastolic diameter (HR per 1-mm increase: 1.10; 95% CI: 1.06-1.13). Multivariable analysis in individuals with cardiac magnetic resonance and late gadolinium enhancement assessment (n = 360, 45%) identified late gadolinium enhancement as an additional independent predictor of DCM development (HR: 2.52; 95% CI: 1.43-4.45).

CONCLUSIONS

Following a first negative screening, approximately 11% of G+ relatives developed DCM during a median follow-up of 3 years. Older age, an abnormal electrocardiogram, lower left ventricular ejection fraction, increased left ventricular end-diastolic diameter, motor sarcomeric genetic variants, and late gadolinium enhancement are associated with a higher risk of developing DCM.

Association of Genetic Variants With Outcomes in Patients With Nonischemic Dilated Cardiomyopathy

BACKGROUND

The clinical relevance of genetic variants in nonischemic dilated cardiomyopathy (DCM) is unsettled.

OBJECTIVES

The study sought to assess the prognostic impact of disease-causing genetic variants in DCM.

METHODS

Baseline and longitudinal clinical data from 1,005 genotyped DCM probands were retrospectively collected at 20 centers. A total of 372 (37%) patients had pathogenic or likely pathogenic variants (genotype positive) and 633 (63%) were genotype negative. The primary endpoint was a composite of major adverse cardiovascular events. Secondary endpoints were end-stage heart failure (ESHF), malignant ventricular arrhythmia (MVA), and left ventricular reverse remodeling (LVRR).

RESULTS

After a median follow-up of 4.04 years (interquartile range: 1.70-7.50 years), the primary endpoint had occurred in 118 (31.7%) patients in the genotype-positive group and in 125 (19.8%) patients in the genotype-negative group (hazard ratio [HR]: 1.51; 95% confidence interval [CI]: 1.17-1.94; P = 0.001). ESHF occurred in 60 (16.1%) genotype-positive patients and in 55 (8.7%) genotype-negative patients (HR: 1.67; 95% CI: 1.16-2.41; P = 0.006). MVA occurred in 73 (19.6%) genotype-positive patients and in 77 (12.2%) genotype-negative patients (HR: 1.50; 95% CI: 1.09-2.07; P = 0.013). LVRR occurred in 39.6% in the genotype-positive group and in 46.2% in the genotype-negative group (P = 0.047). Among individuals with baseline left ventricular ejection fraction ≤35%, genotype-positive patients exhibited more major adverse cardiovascular events, ESHF, and MVA than their genotype-negative peers (all P < 0.02). LVRR and clinical outcomes varied depending on the underlying affected gene.

CONCLUSIONS

In this study, DCM patients with pathogenic or likely pathogenic variants had worse prognosis than genotype-negative individuals. Clinical course differed depending on the underlying affected gene.

Perioperative management of patients with arrhythmogenic syndromes refractory to medical treatment: A clinical case report

Family heart diseases related to sudden death are a group of cardiovascular diseases (cardiomyopathies, channelopathies, aortic diseases …) that require familiarity of the anesthesiologist with the perioperative treatment of complex hemodynamic disorders, as well as their surgical treatment.¹ We present the case of a 12-year-old man diagnosed with non-obstructive hypertrophic cardiomyopathy (MHNO), after cardiorespiratory arrest (PCR), who underwent video-guided thoracoscopy-guided left sympathectomy (VATS) for frequent syncope, despite pharmacological treatment and implantation of an implantable automatic defibrillator (ICD). Whenever arrhythmic syncope occurs in the setting of familial heart disease, left heart denervation should be considered as the next step in the treatment plan.².

Perioperative management of patients with arrhythmogenic syndromes refractory to medical treatment: A clinical case report

Family heart diseases related to sudden death are a group of cardiovascular diseases (cardiomyopathies, channelopathies, aortic diseases...) that require familiarity of the anesthesiologist with the perioperative treatment of complex hemodynamic disorders, as well as their surgical treatment¹. We present the case of a 12-year-old man diagnosed with non-obstructive hypertrophic cardiomyopathy, after cardiorespiratory arrest, who underwent video-guided thoracoscopy-guided left sympathectomy for frequent syncope, despite pharmacological treatment and implantation of an implantable automatic defibrillator. Whenever arrhythmic syncope occurs in the setting of familial heart disease, left heart denervation should be considered as the next step in the treatment plan².

Sudden cardiac death in persons aged 50 years or younger: diagnostic yield of a regional molecular autopsy program using massive sequencing

INTRODUCTION AND OBJECTIVES

Sudden cardiac death (SCD) in young people often has a genetic cause. Consequently, the results of "molecular autopsy" may have important implications for their relatives. Our objective was to evaluate the diagnostic yield of a molecular autopsy program using next-generation sequencing.

METHODS

We performed a prospective study of a cohort of consecutive patients who died from nonviolent SCD, aged ≤ 50 years, and who underwent molecular autopsy using large panels of next-generation sequencing, with subsequent clinical and genetic family screening. We analyzed demographic, clinical, toxicological, and genetic data.

RESULTS

We studied 123 consecutive cases of SCD in persons aged ≤ 50 years. The incidence of SCD was 5.8 cases/100 000 individuals/y, mean age was 36.15±12.7 years, and 95 were men (77%). The cause was cardiac in 53%, unexplained SCD in 24%, toxic in 10.6%, and infant SCD in 4%. Among cardiac causes, ischemic heart disease accounted for 38% of deaths, arrhythmogenic cardiomyopathy for 7%, hypertrophic cardiomyopathy for 5%, and idiopathic left ventricular hypertrophy for 11%. Genetic analysis was performed in 62 cases (50.4%). Genetic variants were found in 42 cases (67.7%), with a mean of 3.4±4 genetic variants/patient, and the variant found was considered to be pathogenic or probably pathogenic in 30.6%. In unexplained SCD, 70% showed some genetic variant. Family screening diagnosed 21 carriers or affected individuals, 5 of whom were at risk, indicating an implantable cardiac defibrillator.

CONCLUSIONS

Protocol-based and exhaustive study of SCD from cardiac causes in persons aged ≤ 50 years is feasible and necessary. In a high percentage of cases, the cause is genetic, indicating the existence of relatives at risk who could benefit from early diagnosis and treatment to avoid complications.

Impact of the creation of specialized units for patients with hypertrophic cardiomyopathy

INTRODUCTION AND OBJECTIVES

According to current international guidelines, hypertrophic cardiomyopathy (HCM) patients should be managed in specialized units. However, there is lack of data on the impact of the creation of these units in the management of HCM patients. Our goal was to assess the impact of the creation of an Inherited Inherited Diseases Cardiac Unit (ICDU) in the current management of patients with HCM.

METHODS

We analyzed 114 consecutive patients (62.6±8 years old, 70.2% males) with HCM. Variables related to optimal management of HCM patients and their family study were recorded, as well as guidance on the risk of sudden death. We analyzed whether patients were assessed by the ICDU or at a general cardiology consultation (GCC).

RESULTS

50 patients were assessed in the IDCU and 64 in the GCC. Familial screening was more frequent in patients assessed by the IDCU (45.3% vs. 4%; p<0.01), requesting more genetic studies of the index case (70.3% vs. 14%; p<0.01) and cardiac magnetic resonance (53.1% vs. 18%; p<0.01). Sudden death risk score was performed more frequently in patients after the creation of an IDCU (67.2% vs. 28%; p<0.01). Treatment with beta-blockers was similar in both groups (72% vs. 78.1%; p=0.24). An implantable cardiac defibrillator was indicated similarly in both groups (12.5% in ICDU and 6% in GC; p=0.24).

CONCLUSIONS

The implementation of an IDCU improved the quality of the medical care for HCM patients by performing a better study of the patients and their families.

Reasons for refusing diagnostic tests and therapeutic recommendations and associated complications in inherited heart diseases. The RELUCTANT study

INTRODUCTION AND OBJECTIVES

Study of inherited heart diseases (IHD) involves performing diagnostic tests, which are sometimes inconvenient or stressful, in asymptomatic relatives. The aim of this study was to analyze refusal to undergo various diagnostic tests and follow therapeutic recommendations.

METHODS

We assessed 1992 consecutive families with IHD to analyze refusal to undergo family screening. The study included 1539 individuals who were recommended to undergo cardiac magnetic resonance, and 837 who were recommended a drug challenge test. To study treatment refusal, we assessed 395 patients with an indication for an implantable cardioverter-defibrillator (ICD) and 402 patients with an indication for anticoagulation.

RESULTS

A total of 28% of families who were recommended to undergo screening for suspected IHD did not attend, but refusal was lower if there was a family history of sudden cardiac death. In all, 23% did not undergo magnetic resonance, and the 2 main reasons were administrative problems (53%) and claustrophobia (18%). Refusal was more common in older people, women, symptomatic persons, individuals with arrhythmias, and relatives. Nearly one fifth (19%) did not take the drug challenge test, due to fear (46%) or administrative issues (25%). Refusal was more frequent in older individuals, asymptomatic persons, those with a history of arrhythmias, relatives, and those with a positive genetic study. Only a minority of patients rejected the treatments (5.1% ICD, 2.5% anticoagulation). The percentage of sudden cardiac death in persons rejecting ICD implantation was high (4.5% per year).

CONCLUSIONS

One fifth of people attending screening for IHD refused to undergo more sophisticated and stressful tests. This study identified several independent predictors associated with refusal. Only a minority of high-risk patients refused treatments such as ICD implantation and anticoagulation.

Genetic Factors Involved in Cardiomyopathies and in Cancer

Cancer therapy-induced cardiomyopathy (CCM) manifests as left ventricular (LV) dysfunction and heart failure (HF). It is associated withparticular pharmacological agents and it is typically dose dependent, but significant individual variability has been observed. History of prior cardiac disease, abuse of toxics, cardiac overload conditions, age, and genetic predisposing factors modulate the degree of the cardiac reserve and the response to the injury. Genetic/familial cardiomyopathies (CMY) are increasingly recognized in general populations with an estimated prevalence of 1:250. Association between cardiac and oncologic diseases regarding genetics involves not only the toxicity process, but pathogenicity. Genetic variants in germinal cells that cause CMY (LMNA, RAS/MAPK) can increase susceptibility for certain types of cancer. The study of mutations found in cancer cells (somatic) has revealed the implication of genes commonly associated with the development of CMY. In particular, desmosomal mutations have been related to increased undifferentiation and invasiveness of cancer. In this article, the authors review the knowledge on the relevance of environmental and genetic background in CCM and give insights into the shared genetic role in the pathogenicity of the cancer process and development of CMY.

Arrhythmogenic cardiomyopathy with left ventricular involvement versus ischemic heart disease: lessons learned from the family study and the reviewed autopsy of a young male

Ischemic heart disease (IHD) is the leading cause of sudden cardiac death (SCD) and often non-thrombosed severe coronary stenoses with or without myocardial scars are detected. Left dominant arrhythmogenic cardiomyopathy (LDAC) is a life-threating rare disease which has been more thoroughly studied in the last 10 years. The macroscopic study of an SCD victim was conducted and re-evaluated 9 years later. The cardiological work-up in his first-degree relatives initially comprised an electrocardiogram (ECG) and an echocardiogram. When they were re-evaluted 9 years later, a cardiac magnetic resonance, an ECG-monitoring, an exercise testing and a genetic study were performed and the pedigree was extended accordingly. In 2008, an IHD was suspected in the sports-triggered SCD of a 37-year-old man upon the postmortem (75% stenosis of the left main and circumflex coronary arteries; the subepicardial left ventricular fibrofatty infiltration with mild myocardial degeneration was assumed to be a past myocardial infarction). No cardiomyopathy was identified in any of the two proband’s sisters. Nine years thereafter, distant relatives were diagnosed with LDAC due to a pathogenic desmoplakin mutation. The reanalysis of the two sisters showed ventricular arrhythmias in one of them without structural heart involvement and the reviewed postmortem of the proband was reclassified as LDAC based on the fibrofatty infiltration; both were mutation carriers. The completion of the family study on 19 family members yielded one SCD due to LDAC (the proband), three living patients diagnosed with LDAC (two with a defibrillator), one mutation carrier without structural ventricular involvement, and 14 healthy relatives (who were discharged) with a very good co-segregation of the mutation. Although rare, LDAC exists and sometimes its differential diagnosis with IHD has to be faced. Modifying previous postmortem misdiagnoses can help family screening to further prevent SCDs.

Clinical Findings and Prognosis of Danon Disease. An Analysis of the Spanish Multicenter Danon Registry

INTRODUCTION AND OBJECTIVES

Danon disease (DD) is caused by mutations in the LAMP2 gene. It is considered a multisystemic disease characterized by hypertrophic cardiomyopathy with pre-excitation and extreme hypertrophy, intellectual disability, myopathy, childhood presentation, and worse prognosis in men. There are scarce data on the clinical characteristics and prognosis of DD.

METHODS

We analyzed the clinical records of patients with DD from 10 Spanish hospitals.

RESULTS

Twenty-seven patients were included (mean age, 31 ± 19 years; 78% women). Male patients showed a high prevalence of extracardiac manifestations: myopathy (80%), learning disorders (83%), and visual alterations (60%), which were uncommon findings in women (5%, 0%, and 27%, respectively). Although hypertrophic cardiomyopathy was the most common form of heart disease (61%), the mean maximum wall thickness was 15 ± 7 mm and dilated cardiomyopathy was present in 12 patients (10 women). Pre-excitation was found in only 11 patients (49%). Age at presentation was older than 20 years in 16 patients (65%). After a median follow-up of 4 years (interquartile range, 2-9), 4 men (67%) and 9 women (43%) died or required a transplant. Cardiac disease and adverse events occurred later in women (37 ± 9 vs 23 ± 16 and 36 ± 20 vs 20 ± 11 years, respectively).

CONCLUSIONS

The clinical characteristics of DD differ substantially from traditional descriptions: age at presentation of DD is older, the disease is not multisystemic in women, and pre-excitation is infrequent.

The importance of genotype-phenotype correlation in the clinical management of Marfan syndrome

Background

Marfan syndrome (MFS) is a disorder of autosomal dominant inheritance, in which aortic root dilation is the main cause of morbidity and mortality. Fibrillin-1 (FBN-1) gene mutations are found in more than 90% of MFS cases. The aim of our study was to summarise variants in FBN-1 and establish the genotype-phenotype correlation, with particular interest in the onset of aortic events, in a broad population of patients with an initial clinical suspicion of MFS.

Material and methods

This single centre prospective cohort study included all patients presenting variants in the FBN-1 gene who visited a Hereditary Aortopathy clinic between September 2010 and October 2016.

Results

The study included 90 patients with FBN-1 variants corresponding to 58 non-interrelated families. Of the 57 FBN-1 variants found, 25 (43.9%) had previously been described, 23 of which had been identified as associated with MFS, while the the remainder are described for the first time. For 84 patients (93.3%), it was possible to give a definite diagnosis of Marfan syndrome in accordance with Ghent criteria. 44 of them had missense mutations, 6 of whom had suffered an aortic event (with either prophylactic surgery for aneurysm or dissection), whereas 20 of the 35 patients with truncating mutations had suffered an event (13.6% vs. 57.1%, p < 0.001). These events tended to occur at earlier ages in patients with truncating compared to those with missense mutations, although not significantly (41.33 ± 3.77 vs. 37.5 ± 9.62 years, p = 0.162).

Conclusions

Patients with MFS and truncating variants in FBN-1 presented a higher proportion of aortic events, compared to a more benign course in patients with missense mutations. Genetic findings could, therefore, have importance not only in the diagnosis, but also in risk stratification and clinical management of patients with suspected MFS.

Electronic supplementary material

The online version of this article (10.1186/s13023-017-0754-6) contains supplementary material, which is available to authorized users.

Comments on the New International Criteria for Electrocardiographic Interpretation in Athletes

Sudden cardiac death is the most common medical cause of death during the practice of sports. Several structural and electrical cardiac conditions are associated with sudden cardiac death in athletes, most of them showing abnormal findings on resting electrocardiogram (ECG). However, because of the similarity between some ECG findings associated with physiological adaptations to exercise training and those of certain cardiac conditions, ECG interpretation in athletes is often challenging. Other factors related to ECG findings are race, age, sex, sports discipline, training intensity, and athletic background. Specific training and experience in ECG interpretation in athletes are therefore necessary. Since 2005, when the first recommendations of the European Society of Cardiology were published, growing scientific evidence has increased the specificity of ECG standards, thus lowering the false-positive rate while maintaining sensitivity. New international consensus guidelines have recently been published on ECG interpretation in athletes, which are the result of consensus among a group of experts in cardiology and sports medicine who gathered for the first time in February 2015 in Seattle, in the United States. The document is an important milestone because, in addition to updating the standards for ECG interpretation, it includes recommendations on appropriate assessment of athletes with abnormal ECG findings. The present article reports and discusses the most novel and relevant aspects of the new standards. Nevertheless, a complete reading of the original consensus document is highly recommended.

The Genetics of Ischemic Heart Disease: From Current Knowledge to Clinical Implications

Ischemic heart disease continues to cause high morbidity and mortality. Its prevalence is expected to increase due to population aging, and its prevention is a major goal of health policies. The risk of developing ischemic heart disease is related to a complex interplay between genetic, environmental, and lifestyle factors. In the last decade, considerable progress has been made in knowledge of the genetic architecture of this disease. This narrative review provides an overview of current knowledge of the genetics of ischemic heart disease and of its translation to clinical practice: identification of new therapeutic targets, assessment of the causal relationship between biomarkers and disease, improved risk prediction, and identification of responders and nonresponders to specific drugs (pharmacogenomics).

Clinical and Genetic Diagnosis of Nonischemic Sudden Cardiac Death

INTRODUCTION AND OBJECTIVES

Nonischemic sudden cardiac death (SCD) is predominantly caused by cardiomyopathies and channelopathies. There are many diagnostic tests, including some complex techniques. Our aim was to analyze the diagnostic yield of a systematic diagnostic protocol in a specialized unit.

METHODS

The study included 56 families with at least 1 index case of SCD (resuscitated or not). Survivors were studied with electrocardiogram, advanced cardiac imaging, exercise testing, familial study, genetic testing and, in some cases, pharmacological testing. Families with deceased probands were studied using the postmortem findings, familial evaluation, and molecular autopsy with next-generation sequencing (NGS).

RESULTS

A positive diagnosis was obtained in 80.4% of the cases, with no differences between survivors and nonsurvivors (P=.53). Cardiac channelopathies were more prevalent among survivors than nonsurvivors (66.6% vs 40%, P=.03). Among the 30 deceased probands, the definitive diagnosis was given by autopsy in 7. A diagnosis of cardiomyopathy tended to be associated with a higher event rate in the family. Genetic testing with NGS was performed in 42 index cases, with a positive result in 28 (66.6%), with no differences between survivors and nonsurvivors (P=.21).

CONCLUSIONS

There is a strong likelihood of reaching a diagnosis in SCD after a rigorous protocol, with a more prevalent diagnosis of channelopathy among survivors and a worse familial prognosis in cardiomyopathies. Genetic testing with NGS is useful and its value is increasing with respect to the Sanger method.

Usefulness of Genetic Testing in Hypertrophic Cardiomyopathy: an Analysis Using Real-World Data

This study sought to determine the usefulness of genetic testing to predict evolution in hypertrophic cardiomyopathy (HCM) and to assess the role of genetic testing in clinical practice. Genetic results of 100 HCM patients tested for mutations in ≥10 HCM-causing genes were evaluated. Patients were classified as with poor (group A) or favourable (group B) clinical course. Forty-five pathogenic mutations (PM) were identified in 28 patients (56 %) from group A and in 23 (46 %) from group B (p = 0.317). Only 40 patients (40 %) exhibited PM that had been previously reported and only 15 (15 %) had PM reported in ≥10 individuals. PM associated with poor prognosis were identified in just five patients from group A (10 %). Genetic findings are not useful to predict prognosis in most HCM patients. By contrast, real-world data reinforce the usefulness of genetic testing to provide genetic counselling and to enable cascade genetic screening.