Reduced Uptake of Family Screening in Genotype-Negative Versus Genotype-Positive Long QT Syndrome

Evaluation of Clinical Practices Related to Variants of Uncertain Significance Results in Inherited Cardiac Arrhythmia and Inherited Cardiomyopathy Genes

Background:

Increasing use of genetic tests have identified many variants of uncertain significance (VUS) in genes associated with inherited arrhythmias and cardiomyopathies. Evaluation of clinical practices, including medical management recommendations for VUS patients and their families, is important to prevent over- or under-treatment that may result in morbidity or mortality. The purpose of this study is to describe practices related to VUS results including information and medical management recommendations providers give patients and their families.

Methods:

An anonymous online survey was distributed to genetic counselors (GCs) and cardiologists who have seen at least one patient for inherited arrhythmias or cardiomyopathies. The survey explored providers’ confidence in counseling, explanation of VUSs, topics covered before and after genetic testing, and clinical recommendations using a hypothetical scenario maximizing uncertainty with an unclear clinical and molecular diagnosis. Descriptive statistics were calculated, and median confidence and likelihood of making various medical recommendations were compared across provider type.

Results:

Providers (N=102) who completed the survey included 29 cardiovascular GCs, 50 GCs from other specialties, and 23 cardiologists. GCs feel more confident than cardiologists counseling about VUS results ( P <0.001); while both cardiovascular GCs and cardiologists feel more confident than other GCs in providing input regarding medical management recommendations ( P =0.001 and P =0.01, respectively). Cardiologists were more likely than cardiac GCs to recommend clinical testing for family members even though testing in the scenario is expected to be uninformative.

Conclusions:

These findings illustrate how the expertise of different providers may impact decision processes, suggesting the need for interdisciplinary clinics to optimize care for challenging cases.

Clinical and genetic evaluation after sudden cardiac arrest

Sudden cardiac arrest (SCA) and sudden cardiac death (SCD) can be attributed to cardiac, respiratory, metabolic, and toxicologic etiologies. Most cases of SCD are caused by coronary artery disease and approximately 40% of cardiac arrests are unexplained. Inherited arrythmias and cardiomyopathies are important contributors to SCA and SCD. Identifying an inherited condition after such an event not only has important ramifications for the individual, but also for relatives who may be at risk for the familial condition. This review will provide an overview of inherited cardiovascular disorders than can predispose to SCA/SCD, review the diagnostic evaluation for an individual and/or family after an SCA/SCD, and discuss the role of genetic testing.

The uptake of family screening in hypertrophic cardiomyopathy and an online video intervention to facilitate family communication

Background

Individuals with hypertrophic cardiomyopathy (HCM), even when asymptomatic, are at‐risk for sudden cardiac death and stroke from arrhythmias, making it imperative to identify individuals affected by this familial disorder. Consensus guidelines recommend that first‐degree relatives (FDRs) of a person with HCM undergo serial cardiovascular evaluations.

Methods

We determined the uptake of family screening in patients with HCM and developed an online video intervention to facilitate family communication and screening. Family screening and genetic testing data were collected through a prospective quality improvement initiative, a standardized clinical assessment and management plan (SCAMP), utilized in an established cardiovascular genetics clinic. Patients were prescribed an online video if screening of their FDRs was incomplete and a pilot study on video utilization and family communication was conducted.

Results

Two‐hundred and sixteen probands with HCM were enrolled in SCAMP Phase I and 190 were enrolled in SCAMP Phase II. In both phases, probands reported that 51% of FDRs had been screened (382/749 in Phase I, 258/504 in Phase II). Twenty patients participated in a pilot study on video utilization and family communication. Nine participants reported watching the video and six participants reported sharing the video with relatives; however only one participant reported sharing the video with relatives who were not yet aware of the diagnosis of HCM in the family.

Conclusion

Despite care in a specialized cardiovascular genetics clinic, approximately one half of FDRs of patients with HCM remained unscreened. Online interventions and videos may serve as supplemental tools for patients communicating genetic risk information to relatives.

Genetic testing and cascade screening in pediatric long QT syndrome and hypertrophic cardiomyopathy

BACKGROUND

The efficacy of cascade screening for the inherited heart conditions long QT syndrome (LQTS) and hypertrophic cardiomyopathy (HCM) is incompletely characterized.

OBJECTIVE

The purpose of this study was to examine the use of genetic testing and yield of cascade screening across diverse regions in the United States and to evaluate obstacles to screening in multipayer systems.

METHODS

An institutional review board-approved 6 United States pediatric center retrospective chart review of LQTS and HCM patients from 2008-2014 was conducted for (1) genetic test completion and results and (2) family cascade screening acceptance, methods, results, and barriers.

RESULTS

The families of 315 index patients (mean age 9.0 ± 5.8 years) demonstrated a 75% (254) acceptance of cascade screening. The yield of relative screening was 39% (232/601), an average of 0.91 detected per family. Genetic testing was less utilized in HCM index patients and relatives. Screening participation was greater in families of gene-positive index patients (88%) (P <.001) compared to gene-negative patients (53%). Cascade method utilization: Cardiology-only 45%, combined genetic and cardiology 39%, and genetic only 16%. Screening yield by method: combined 57%, genetic-only 29%, and cardiology-only 20%. Family decisions were the leading barriers to cascade screening (26% lack of followthrough and 26% declined), whereas insurance (6%) was the least cited barrier.

CONCLUSION

Family participation in cascade screening is high, but the greatest barriers are family mediated (declined, lack of followthrough). Positive proband genetic testing led to greater participation. Cardiology-only screening was the most utilized method, but combined cardiology and genetic screening had the highest detection.

Family Communication About Genetic Risk of Hereditary Cardiomyopathies and Arrhythmias: an Integrative Review

Screening for hereditary cardiomyopathies and arrhythmias (HCA) may enable early detection, treatment, targeted surveillance, and result in effective prevention of debilitating complications and sudden cardiac death. Screening at-risk family members for HCA is conducted through cascade screening. Only half of at-risk family members are screened for HCA. To participate in screening, at-risk family members must be aware of their risk. This often relies on communication from diagnosed individuals to their relatives. However, family communication is not well understood and is ripe for developing interventions to improve screening rates. Until very recently, family communication of genetic risk has been mostly studied in non-cardiac disease. Using this non-cardiac literature, we developed the family communication of genetic risk (FCGR) conceptual framework. The FCGR has four main elements of the communication process: influential factors, communication strategies, communication occurrence, and reaction to communication. Using the FCGR, we conducted an integrated review of the available literature on genetic risk communication in HCA families. Descriptive analysis of 12 articles resulted in the development of categories describing details of the FCGR elements in the context of HCA. This review synthesizes what is known about influential factors, communication strategies, communication occurrence, and outcomes of communication in the context of HCA.

Patient Recall, Interpretation, and Perspective of an Inconclusive Long QT Syndrome Genetic Test Result

Patients' perceptions of inconclusive results have been previously investigated in cancer genetics. The differences in how patients recall and interpret an uninformative test result compared to a known pathogenic result can affect medical decisions post disclosure. However, there is little to no data available on patients' interpretation and perception of uninformative genetic results in inherited heart disease. We report the results of a qualitative analysis of 16 telephone interviews with participants who received a negative or a variant of unknown significance (VUS) result from Long QT syndrome (LQTS) genetic testing. Our results suggest that the type of result (negative versus VUS) does not affect recall, regardless of the reason for testing. When receiving a negative result, a majority of participants appropriately perceived no change in their diagnosis, while the perception of risk for family members varied. The majority of participants felt they maintained an awareness of their condition after the result disclosure, and that clinical follow-up was similar to that planned prior to the genetic test result. Further work is needed to determine if there are any differences between obtaining a VUS result versus a negative result in this population.

Clinical application of next-generation sequencing for Mendelian diseases

Over the past decade, next-generation sequencing (NGS) has led to an exponential increase in our understanding of the genetic basis of Mendelian diseases. NGS allows for the analysis of multiple regions of the genome in one single reaction and has been shown to be a cost-effective and efficient tool in investigating patients with Mendelian diseases. More recently, NGS has been successfully deployed in the clinics, with a reported diagnostic yield of ~25 %. However, recommendations on clinical implementation of NGS are still evolving with numerous key challenges that impede the widespread use of genetics in everyday medicine. These challenges include when to order, on whom to order, what type of test to order, and how to interpret and communicate the results, including incidental findings, to the patient and family. In this review, we discuss these challenges and suggest guidelines on implementing NGS in the routine clinical workflow.