Screening for Dilated Cardiomyopathy in At-Risk First-Degree Relatives

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.

Screening for dilated cardiomyopathy in immediate family members: to whom, how, when (and where)

Dilated cardiomyopathy (DCM) is defined by the presence of left ventricular dilation and systolic dysfunction in the absence of coronary artery disease, valvular disease, congenital heart disease, or altered haemodynamic conditions. Dilated cardiomyopathy can recognize multiple aetiologies, including infectious processes, effect of toxic substances, immunological mechanisms, and genetic causes. In recent years, many genes coding for proteins involved in the structure and function of the cardiomyocytes have been associated with the development of DCM, making the identification of familial forms increasingly frequent. At the same time, an ever-increasing use of cardiac magnetic resonance imaging has made it possible to identify early morpho-functional alterations in subjects with initial forms of the disease, or carriers of pathogenic genetic variants. The increasingly in-depth understanding of the genetic and molecular mechanisms operating in DCM has also favoured the development of new therapeutic strategies including drugs with molecular targets and gene therapies. In this panorama, screening of family members of patients affected by DCM represents an important tool for early diagnosis, treatment, and prognostic stratification. In relation to its clinical relevance and its complexity, it is important that family screening and follow-up of identified patients are carried out in units dedicated to the treatment and study of cardiomyopathies.

Editor-in-Chief's Top Picks From 2023

Each week, I record audio summaries for every paper in JACC, as well as an issue summary. This process has become a true labor of love due to the time they require, but I am motivated by the sheer number of listeners (16M+), and it has allowed me to familiarize myself with every paper that we publish. Thus, I have selected the top 100 papers (Original Investigations, Review Articles, Society Documents, and the Global Burden of Diseases) from distinct specialties each year. In addition to my personal choices, I have included papers that have been the most accessed or downloaded on our websites, as well as those selected by the JACC Editorial Board members. In order to present the full breadth of this important research in a consumable fashion, we will present these abstracts in this issue of JACC, as well as their Central Illustrations∗ and podcasts. The highlights comprise the following sections: Aorta; Basic and Translational Science; Cardiac Failure, Myocarditis, and Pericarditis; Cardiomyopathies and Genetics; Congenital Heart Disease; Coronary, Peripheral, and Structural Interventions; Coronavirus; Health Promotion and Preventive Cardiology; Imaging; Metabolic and Lipid Disorders; Neurovascular Disease and Dementia; Rhythm Disorders and Thromboembolism; and Valvular Heart Disease.1-104 ∗ To view the full manuscript, including the full-sized Central Illustration, please refer to the original publication in JACC.

The DCM Project Portal: A direct-to-participant platform of The DCM Research Project

Study objective

To develop a digital platform to conduct family-based, dilated cardiomyopathy (DCM) genetic research.

Design

The DCM Project Portal, a direct-to-participant electronic recruitment, consent, and communication tool, was designed using prior experience with traditional enrollment methods and characteristics and feedback of current participants.

Participants

DCM patients (probands) and their family members enrolled from June 7, 2016 to March 15, 2020 at 25 US advanced heart failure programs.

Results

The portal was designed as a self-guided, three module (registration, eligibility, and consent) process with supporting informational and messaging resources integrated throughout. The experience is tailored to user type and the format adaptable with programmatic growth. Characteristics of participants of the recently completed DCM Precision Medicine Study were assessed as an exemplary user population. A majority of the diverse (34 % non-Hispanic Black (NHE-B), 9.1 % Hispanic; 53.6 % female) proband (n = 1223) and family member (n = 1781) participants aged ≥18 years reported not at all or rarely having problems learning about their health from written information (81 %) and a high confidence in completing medical forms (77.2 % very much or often confident), supporting a self-guided model. A majority of participants across age and race-ethnicity groups reported internet access, with highest rates of no reported access in those ≥77 years (31.9 %), NHE-B (25.2 %), and Hispanic (22.9 %), a similar pattern to those reported by the US Census Bureau as of 2021.

Conclusions

The portal is an example of a digital approach to family-based genetic research that offers opportunity to improve access and efficiency of research operations.

The DCM Project Portal: A direct-to-participant platform of The DCM Research Project

Study Objective

To develop a digital platform to conduct family-based, dilated cardiomyopathy (DCM) genetic research.

Design

Innovative approaches are needed to achieve large family enrollment targets. The DCM Project Portal, a direct-to-participant electronic recruitment, consent, and communication tool, was designed using prior experience with traditional enrollment methods, characteristics and feedback of current participants, and internet access of the US population.

Participants

DCM patients (probands) and their family members.

Results

The portal was designed as a self-guided, three module (registration, eligibility, and consent) process with internally created supporting informational and messaging resources integrated throughout. The experience can be tailored to user type and the format adapted with programmatic growth. Characteristics of participants of the recently completed DCM Precision Medicine Study were assessed as an exemplary user population. A majority of the diverse (34% non-Hispanic Black (NHE-B), 9.1% Hispanic; 53.6% female) proband (n=1223) and family members (n=1781) participants aged ≥18 years reported not at all or rarely having problems learning about their health from written information (81%) and a high confidence in completing medical forms (77.2% very much or often confident). A majority of participants across age and race-ethnicity groups reported internet access, with highest rates of no reported access in those ≥77 years, NHE-B, and Hispanic, which reflects patterns similar to rates reported by the US Census Bureau as of 2021.

Conclusions

Digital enrollment tools offer opportunity to improve access and efficiency. The portal is an example of a digital approach to family-based genetic research.