Prof Sanjay Sharma, Professor of Cardiology and Lead for the Inherited Cardiomyopathies and Sports Cardiology Unit, Cardiovascular and Cell Sciences Research Institute. St George’s, University of London, UK, speaks with Cardio Debate about sudden death in athletes.
What is the magnitude of the problem of sudden cardiac death in the young in the UK and worldwide?
Sudden Cardiac Death is a feared complication of cardiovascular disease in the UK. It affects about 120,000 people in this country, and the vast majority are aged between 50 and 80 years old. Very occasionally a young individual will die suddenly from a heart problem and these deaths clearly cause a lot of concern in the community because they are counter-intuitive and lead to a large number of life years lost.
The magnitude of the problem is actually greater than what we once believed, and affects 12 and 16 young individuals per week, and that amounts to between 600 and 1000 deaths (per year). If one imagines that these individuals lose around 50 years of life each, and that these diseases can be detected through simple measures such as ECG, echocardiography, and that there are treatments that actually prevent these deaths, then I think it’s very important that we do try to identify young individuals who might be at risk.
How do you identify high-risk patients?
The sad thing about this whole thing is that sudden death in young people affects people who are apparently well and look healthy, and have no symptoms at all.
In fact 80% of young individuals who die suddenly from heart diseases such as the cardiomyopathies and the ion channel diseases, and congenital accessory pathways of the heart have no symptoms whatsoever and sudden death is the first presentation.
It’s important to emphasise that many of these conditions are genetic, therefore it is very important to be aware whether a first-degree relative such as a father, a brother or a sister may also be affected, or may have died prematurely.
In individuals who have that sort of family history it’s not very difficult. Those individuals do need comprehensive evaluation for heart muscle diseases and electrical faults.
It’s very difficult to identify others because they have no symptoms at all, and some form of screening procedure is required. And probably the most effective screening procedure is the ECG, and this practice is conducted by sporting organisations throughout the UK including the Football Association, the English Institute of Sport, the Rugby Union and the Rugby League. But you can see that it’s confined to the highest echelons of sport, whereas we know that the vast majority of people who die are usually sedentary and recreational, and often of school age – so something a little more elaborate is needed in this country.
Who in the UK are carrying our screening programmes to identify patients at high risk of sudden death?
In Italy where there is a nationally sponsored screening programme, the ECG has been very useful at detecting young individuals with heart diseases. And since its implication about 30 years ago, sudden death in sport particularly, has gone down from 3.6 per 100,000 to 0.4 per 100,000 and that represents a 90 per cent reduction in sudden cardiac death in sportsmen.
There is no nationally sponsored screening programme in the UK, but there are certain charitable organisations such as Cardiac Risk in the Young (CRY) who do promote and perform screening at a cost-effective rate of value of £35 each. And this involves a health questionnaire pertaining to cardiovascular symptoms or a family history, and an ECG. Now the ECG will clearly detect electrical faults such as Wolff-Parkinson-White syndrome, Long QT syndrome and Brugada syndrome, but it will also raise the suspicion of a heart muscle disorder such as hypertrophic cardiomyopathy in which ECG is abnormal in around 95 per cent of cases.
In this country, if we do perform the CRY screening programme, which we have done in about 20,000 people here at St George’s, then we find the pick up rate for a very serious condition is 1 in 300. The chance, or the ability to identify a relatively minor congenital abnormality is 1 in 100, at the expense of a false positive rate of less than 4 per cent.
Can you give us some clues as to what to look for when trying to characterise individuals who want to engage in sport but may be at a high risk of cardiac events?
The good news is that sudden death in sport is rare, and affects only 1 in 50,000 individuals. And therefore if a sporting organization does not perform screening – the NHS doesn’t believe that it is really part of the NHS’ remit to screen such young asymptomatic individuals – in that group of individuals there are charitable organisations such as Cardiac Risk in the Young who run a screening programme here at St George’s twice a month, and this screening programme is advertised daily in the Evening Standard and can be resourced from the Internet. People who are interested can sign on if they are aged between 14 and 35 years and have a cardiac evaluation here at St George’s hospital one weekend.
Clearly people who have symptoms such as chest tightness, breathlessness that is disproportionate to the amount of exercise being performed, palpitation, dizziness, syncope or a family history of cardiac disease in a first degree relative aged under 40 years – those individuals are basically eligible to be screened on the NHS anyway, but these are important reasons for screening and I think that these people should not be deprived of screening if they have any of those parameters.