Cardiac death in the young in Scotland: implications for screening

Cardiovascular pre-participation screening in sport remains a controversial area. The general consensus is that it should be available given the increased risk of sudden cardiac death with exercise, but debate exists to the format of this screening. Part 1 of this thesis examines the incidence and epidemiology of death in young people to set the context; Part 2 evaluates the results of the Cardiac Assessment in Young Athletes (CAYA) programme in Scotland. Part 1 investigated a database of 41,049 deaths in those aged 0-35 years in Scotland from 1986-2008. Information such as location of death, whether a PM had taken place and cause of death was examined for all subjects with deaths categorised as those which occurred in-hospital or out-of-hospital and by age category and sex. Cardiac deaths (n=2084) were then investigated further. Analysis showed that the majority of deaths in young people in Scotland are due to accidents (27%), self-harm (16.2%) and cancers (11.8%). Coronary artery disease is the largest contributor of cardiac deaths in young people in Scotland (30%) with the greatest number occurring out-of-hospital (55.3%). Only a relatively small number of deaths (0.9% of total) were due to conditions that would be identified and potentially prevented by a cardiac screening programme. Part 2: The CAYA study was based on the Italian Model of screening by personal and family history, physical examination and resting 12-lead ECG, with the addition of an echocardiogram for all participants. Data was available for 1713 subjects from the CAYA study from October 2009-December 2012. Results showed a high incidence of hypertension in this young, athletic population, with a pilot study suggesting that this is likely to be 'white coat hypertension'. Screening with ECG identified 3 subjects with Wolff Parkinson-White syndrome and 1 with Long QT syndrome. Around 5% of subjects demonstrated left ventricular hypertrophy out with normal limits on echo (>13mm), but no structural abnormalities such as cardiomyopathy were diagnosed. Use of the ECG in cardiac screening remains controversial but these results suggest that, although the ECG is not a useful diagnostic tool for identifying those with left ventricular hypertrophy, it has a high negative predictive value meaning it can identify those without pathology. In conclusion, these results do not support the inclusion of echocardiography as a tool in cardiovascular screening in Scotland. The majority of cardiovascular deaths identified in this study were due to undiagnosed coronary heart disease which would not be identified by screening. Other causes of sudden cardiac death which may be identified by screening, such as familial arrhythmias and cardiomyopathies, are rare in Scotland. A screening service with ECG should be available to athletes and young people in Scotland but this should remain voluntary for those with symptoms or a positive family history. Improved first aid education and provision of defibrillators at sporting facilities would perhaps help to reduce the number of fatalities that occur in young athletes