Sudden death in sport: a drastic decline in cases and new diagnostic methods

Following the introduction in 2010 of the updated diagnostic criteria for arrhythmogenic cardiomyopathy (ACM), the number of competitive athletes who were victims of sudden death caused by ACM fell significantly, from 0.43 to 0.14 cases per 100,000 people/year. The overall incidence of sudden death from all causes in people who take part in sport also declined over the same period, from 1.41 to 0.64 cases per 100,000 people/year. 

In particular, among Veneto athletes who died suddenly, the proportion attributable to arrhythmogenic cardiomyopathy fell from 31% to 22% between the two periods.

This is the finding of the study published in the prestigious journal «Circulation: Arrhythmia and Electrophysiology», conducted by the research group of the Cardiovascular Pathology Unit of the Hospital Trust and the University of Padua, which analysed four decades of data (1985-2024) collected through the Regional Registry of Sudden Death in the Young. The registry, unique in Italy for continuity and the rigour of autopsy diagnosis, has been active for almost forty years in the Veneto Region and today offers a unique view of the evolution of sudden cardiac death (SCD) in competitive athletes caused by arrhythmogenic cardiomyopathy (ACM), a genetic disease that progressively replaces the myocardium with fibro-fatty tissue.

«These results build on more than four decades of a mandatory pre-participation screening programme, active in Italy since 1982, which provides for all competitive athletes a medical history, physical examination, 12-lead electrocardiogram and limited exercise test. The authors stress that the progressive refinement of the diagnostic criteria and growing awareness of the disease among sports physicians have probably contributed to earlier identification of individuals at risk.» explains Cristina Basso, Director of the Department of Cardiac, Thoracic and Vascular Sciences and Public Health (DCTV) of the University of Padua and corresponding author of the study.

«Perhaps the most significant finding emerging from our study concerns the transformation of the disease profile – says Monica De Gaspari, of the DCTV and first author of the research -. Whereas until the 1990s arrhythmogenic cardiomyopathy almost always presented in its classic form affecting the right ventricle or both ventricles — more readily recognisable with electrocardiogram and echocardiogram — in recent years there has been a shift towards the variant with predominant or exclusive involvement of the left ventricle, which has increased from 4.2% to 9.1% of total cases of sudden death from ACM between the period before and the period after 2010.»

This "left-sided" variant of the disease is particularly insidious and difficult to detect with electrocardiogram and two-dimensional echocardiogram. In the entire series of 51 athletes who died from ACM, the echocardiogram was positive in only 5.8% of the cases in which it was performed.

The study shows instead that contrast-enhanced cardiac magnetic resonance imaging (CE-CMR) is the tool capable of revealing the myocardial damage typical of this variant, through the identification of the fibrosis marker and arrhythmogenic substrate. In the only case in the series in which this examination had been carried out during life, the result was positive. Similarly, among four former athletes disqualified because of abnormalities found during screening and who later died during non-competitive activity, contrast-enhanced magnetic resonance imaging was positive in all cases that underwent the examination, despite a normal echocardiogram.

On the basis of these data, the authors recommend a high index of suspicion in athletes who present abnormalities at first-level screening — in particular low ventricular contraction voltages and exercise-induced ventricular arrhythmias — to be investigated not only with echocardiography, but also with contrast-enhanced magnetic resonance imaging, especially in the presence of further suspicious elements such as positive family history, symptoms or other electrocardiographic abnormalities.

The data finally confirm a clear male predominance of sudden death from arrhythmogenic cardiomyopathy in sport: out of 51 total cases, only one involved a female athlete, a finding consistent with the international literature on the lower arrhythmic risk observed in women with the same disease.