Sudden Death in Young Competitive Athletes Due to Arrhythmogenic Cardiomyopathy: A 4-Decade National Referral Center Experience

BACKGROUND: Arrhythmogenic cardiomyopathy (ACM) is a major cause of sudden cardiac death (SCD) in competitive athletes. We aimed to evaluate the prevalence and characteristics of ACM with the increased awareness of the disease at preparticipation screening after the introduction of the 1994 and 2010 diagnostic criteria. METHODS: The North-East Italy registry of juvenile SCD (≤40 years old) was searched for competitive athletes dying due to ACM in the time interval from 1985 to 2024. Cases referred from other regions were also included. Clinical and pathology data were analyzed according to guidelines. RESULTS: ACM was the cause of SCD in 29% of athletes. The incidence rate of SCD in athletes was 0.43 (0.27-0.65) versus 0.14 (0.05-0.33) per 100 000/y before and after 2010, respectively. Fifty-one athletes with ACM (50 men, 25±6.4 years) were enrolled. The pattern was right ventricular/biventricular in 74.5% and left ventricular in 25.5% (41% after 2010). Fibrofatty replacement was transmural in 63% of right ventricular/biventricular ACM and exclusively subepicardial-midmural in left ventricular ACM. First-line preparticipation screening revealed abnormalities in 62.7% (83.3% before 1994 and 40.9% after 2010). Twelve-lead ECG abnormalities were present in 50.9% (60.5% in right ventricular/biventricular ACM and 23% in left ventricular ACM), with negative T waves in 39.2% and low QRS voltage in 25.5%. Premature ventricular complexes/nonsustained ventricular tachycardia with left bundle-branch block or multiple morphologies were present on basal or limited exercise ECG in 35.3%. Maximal stress test, Holter, and 2-dimensional echocardiography were positive in 55%, 45.4%, and 5.8% of cases, respectively. In the only case who underwent contrast-enhanced cardiac magnetic resonance, late gadolinium enhancement was detected. CONCLUSIONS: ACM-related SCD incidence appeared lower in the post-2010 period. A phenotypic shift toward the left ventricular variant is observed, with ECG changes in a minority of cases and usually normal 2-dimensional echocardiography. If the index of suspicion is high, contrast-enhanced cardiac magnetic resonance is crucial for early identification and SCD prevention.