Highlights on cardiogenomics from the ESC Congress 2022

New ESC Clinical Practice Guidelines

A highlight of the meeting was undoubtedly the presentation of the clinical practice guidelines on cardio-oncology¹ pulmonary hypertension,² non-cardiac surgery,³  ventricular arrhythmias and sudden cardiac death.⁴

In this latest version of the ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death, there are relevant novelties regarding the management of patients with inherited cardiovascular conditions.⁴ A few points are highlighted here:

• It is recommended to perform genetic testing (including at least LMNA, PLN, RBM20, and FLNC genes) in patients with dilated cardiomyopathy/hypokinetic non-dilated cardiomyopathy (DCM/HNDCM) and AV conduction delay at <50 years, or who have a familial history of DCM/HNDCM or SCD in a first-degree relative (at age <50 years).
• Pathogenic mutations in LMNA, PLN, FLNC and RBM20 genes are recognised as risk factors for ventricular arrhythmias and sudden death in patients with dilated cardiomyopathy and non-dilated hypokinetic cardiomyopathy with LVEF <50%. In these patients, ICD implantation should be considered if they also present with syncope, LGE on CMR, or inducible VT on electrophysiological study.
• Specific recommendations are provided for the management of patients with congenital heart disease, idiopathic VF, acquired long QT syndrome, Brugada Syndrome, early repolarisation syndrome, catecholaminergic polymorphic VT and short QT syndrome.

Novel research

In addition to the new clinical practice guidelines, during ESC Congress 2022 we were able to enjoy novel research highlighted by 3,218 abstracts submitted by scientists from more than 81 countries, with Germany leading the way with the highest number of abstracts.

MYH7-related dilated cardiomyopathy

One example is the study addressing the Natural History of MYH7-Related Dilated Cardiomyopathy⁵ from the European Genetic Cardiomyopathies Initiative Investigators with Fernando de Frutos and Pablo García-Pavía as first author and corresponding author (Heart Failure and Inherited Cardiac Diseases Unit, Department of Cardiology, Hospital Universitario Puerta de Hierro, IDIPHISA, Madrid, Spain), respectively.

Even though pathogenic MYH7 mutations have been detected in up to 5% of individuals with dilated cardiomyopathy (DCM), data on the clinical characteristics and natural history of MYH7-associated DCM are scarce. Here, the authors presented the largest cohort of patients and carriers with MYH7 mutations recruited in a multicentre study.

The most common cardiac phenotype among patients carrying MYH7 mutations was DCM and left ventricular non-compaction was common. Heart failure dominated over ventricular arrhythmias (VAs), which were only detected in patients with ejection fraction ≤35%. DCM was found in up to 16% of individuals below age 18 years, suggesting the need to screen for carriers of this mutation earlier in childhood. In addition, individuals with MYH7 variants of unknown significance (VUS) developed DCM and VAs just as often as individuals with pathogenic MYH7 variants, suggesting that most VUS are pathogenic.

As conclusion, MYH7-related DCM is characterised by early age of onset, high phenotypic expression, low left ventricular reverse remodelling, and frequent progression to end-stage heart failure with low incidence of VAs.

Marfan syndrome

There was also another relevant work presented at ESC Congress 2022: MTT - Assessing the effects of ARBs and beta-blockers in Marfan Syndrome from the The Marfan Treatment Trialists’ Collaboration, with Alex Pitcher from Oxford University Hospitals NHS Trust (UK) as first author.

Marfan syndrome (MS) affects about 1 in 5,000 people. It is caused by pathological variants in the FBN1 gene, associating progressive aortic root enlargement leading to a significant life-threatening aortic dissection and rupture. Beta-blockers (β-blockers) have been widely used to prevent aortic dissection despite limited evidence, and recently different groups analysed the benefit from angiotensin receptors blockers (ARBs) with conflicting results.

The primary aim of this study was to estimate the effects of (i) ARBs and (ii) β-blockers on the change in aortic root size in patients with Marfan syndrome and no previous aortic root surgery.

This study included data from 1,442 Marfan syndrome patients who participated in seven treatment trials. The meta-analysis did not involve pooling of data, but rather a collaboration between the original trialists and the meta-analysis. There were 7 trials divided in two groups:

• Four studies involving 746 patients compared ARBs to placebo or a control medication.
• Three trials including 766 patients compared ARBs to beta-blockers.

The primary outcome was aortic root enlargement, a predictor of life-threatening aortic dissection and rupture.

The authors found that in patients with Marfan syndrome and no previous aortic surgery, ARBs reduced the rate of increase of the aortic root Z score by about one half, including among those taking β-blockers. The effects of β blockers were similar to those of ARBs. Moreover, the authors also concluded that there is data to suggest that the effects of β-blockers and ARBs are independent and potentially additive. Combination therapy with both from the time of diagnosis would provide even greater reductions in the rate of aortic enlargement than either treatment alone, which may lead to a delay in the need for aortic surgery.

Other sessions related to cardiogenomics (non-exhaustive list)

• UK Biobank: a unique global platform for cardiovascular discovery science
• Sudden cardiac death in the young: all you need to know
• When and how to do patient workup for a genetic cause of heart failure
• Myocarditis and non-ischaemic DCM
• Meet the Experts: imaging to stratify for SCD risk in patients with cardiomyopathies: latest insights
• Are polygenic risk scores ready for prime time?
• How do common genetic variants cause cardiac diseases?
• ESC Geoffrey Rose Lecture in Population Sciences
• Late-Breaking Science - Innovations in drug treatment
• Management of hypertrophic cardiomyopathy
• Identifying obstructive HCM: expert perspectives
• Cardiomyopathies : clinical cases