Iezzi, Lorena

Arrhythmogenic cardiomyopathies (ACMs) are a phenotypically and etiologically heterogeneous group of myocardial disorders characterized by fibrotic or fibro-fatty replacement of ventricular myocardium, electrical instability, and an elevated risk of sudden cardiac death. Initially identified as a right ventricular disease, ACMs are now recognized to include biventricular and left-dominant forms. Genetic causes account for a substantial proportion of cases and include desmosomal variants, non-desmosomal variants, and familial gene-elusive forms with no identifiable pathogenic mutation. Nongenetic etiologies, including post-inflammatory, autoimmune, and infiltrative mechanisms, may mimic the phenotype. In many patients, the disease remains idiopathic despite comprehensive evaluation. Cardiac magnetic resonance imaging has emerged as a key tool for identifying non-ischemic scar patterns and for distinguishing arrhythmogenic phenotypes from other cardiomyopathies. Emerging classifications propose the unifying concept of scarring cardiomyopathies based on shared structural substrates, although global consensus is evolving. Risk stratification remains challenging, particularly in patients without overt systolic dysfunction or identifiable genetic markers. Advances in tissue phenotyping, multi-omics, and artificial intelligence hold promise for improved prognostic assessment and individualized therapy.

Abstract Arrhythmogenic cardiomyopathy (ACM) is addressed in international guidelines and expert consensus statements. To assist clinicians in their routine practice and support decision-making, we performed a systematic review of the most relevant guidelines and recommendations for ACM diagnosis and management. Our search, covering MEDLINE, EMBASE, and resources from scientific societies over the last 10 years, identified two guidelines and three consensus statements that met rigorous inclusion criteria for detailed analysis. In the examined documents, key areas of agreement included the critical role of cardiac imaging for initial diagnosis and ongoing monitoring, genetic testing in index patients, ventricular arrhythmia management, catheter ablation indications, heart failure treatment strategies, and exercise recommendations. However, significant differences were found in definitions and diagnostic criteria for ACM, interpretation of phenocopies, management of family members, and criteria for implantable cardioverter defibrillator implantation. Additional discrepancies emerged regarding the role of multidisciplinary teams, non-cardiac surgical considerations, atrial fibrillation management, and reproductive issues. Crucially, there remain considerable gaps in evidence, especially in areas such as the management and follow-up of patients with potential or borderline ACM diagnoses, as well as the care of their relatives. The clinical implications of genetic findings, along with the clinical management of left-dominant, biventricular phenotypes, and hot phases of disease, are also insufficiently addressed. Furthermore, a critical shortfall is the lack of externally validated risk assessment tools to guide clinical decision-making. Bridging these gaps could help guiding future research and guideline development towards improving patient outcomes.

Abstract Dilated cardiomyopathy (DCM) is extensively discussed in numerous expert consensus documents and international guidelines, with differing recommendations. To support clinicians in daily practice and decision-making, we conducted a systematic review of key guidelines and recommendations concerning the diagnosis and clinical management of DCM. Our research encompassed MEDLINE and EMBASE databases for relevant articles published, as well as the websites of relevant scientific societies. We identified two guidelines and one scientific statement that met stringent criteria, thereby qualifying them for detailed systematic analysis. Our review revealed consensus on several key aspects: the definition of DCM, the use of B-type natriuretic peptides and high-sensitivity troponin in laboratory testing, the essential role of multimodality cardiovascular imaging for initial diagnosis, genetic counselling, and the management of advanced disease. Nonetheless, notable areas of variation included the formation of multidisciplinary management teams, the role of cascade genetic testing, pathways for arrhythmic risk stratification, and the criteria for prophylactic defibrillator implantation. Significant evidence gaps persist, particularly regarding the clinical trajectory of genetic, non-genetic and gene-elusive forms of DCM, the use of cardiovascular magnetic resonance in phenotype-negative family members with genotype-positive probands, and the development of potential aetiology-oriented therapies. Addressing these gaps could enhance clinical outcomes and inform future research directions and guideline development.