Phenotypic Expression and Clinical Outcomes in Patients with Arrhythmogenic Cardiomyopathies.

BACKGROUND In recent years, it has become evident that arrhythmogenic cardiomyopathy (ACM) displays a wide spectrum of ventricular involvement. Furthermore, the influence of various clinical phenotypes on the prognosis of the disease is currently being assessed. OBJECTIVES The purpose of this study was to evaluate the impact of phenotypic expression in ACM on patient outcomes. METHODS We conducted an analysis of 446 patients diagnosed with ACM. These patients were categorized into 3 groups based on their phenotype: arrhythmogenic right ventricular cardiomyopathy (ARVC) (right -dominant ACM), arrhythmogenic left ventricular cardiomyopathy (ALVC) (left -dominant ACM), and biventricular arrhythmogenic cardiomyopathy (BIV). We compared clinical, instrumental, and genetic findings among these groups and also evaluated their outcomes RESULTS Overall, 44% of patients were diagnosed with ARVC, 23% with ALVC, and 33% with BIV forms. Subjects showing with ARVC and BIV phenotype had a significantly higher incidence of life -threatening ventricular arrhythmias compared with ALVC (P < 0.001). On the other hand, heart failure, heart transplantation, and death caused by cardiac causes were more frequent in individuals with BIV forms compared to those with ALVC and ARVC (P < 0.001). Finally, patients with an ALVC phenotype had a higher incidence of hot phases compared with those with ARVC and BIV forms (P 1/4 0.013). CONCLUSIONS The comparison of ACM phenotypes demonstrated that patients with right ventricular involvement, such as ARVC and BIV forms, exhibit a higher incidence of life -threatening ventricular arrhythmias. Conversely, ACM forms characterized by left ventricular involvement, such as ALVC and BIV, show a higher incidence of heart failure, heart transplantation, and hot phases. (J Am Coll Cardiol 2024;83:797-807) (c) 2024 by the American College of Cardiology Foundation.