More than 11,000 adolescent soccer players in the UK were examined over 20 years and it was found that routine screenings of the heart prevented only a handful of sudden cardiac fatalities while exercising.

A cardiac issue was found in one among 266 players that might result in abrupt death. Merely 1 in 1,396 expired suddenly from some sort of heart disease, being eight cases in total. However, six out of those eight athletes emerged out of the one-time heart screening including electrocardiograms (ECGs) and ultrasound untarnished.

This is the foremost study to offer a trustworthy estimate of the risks, said lead author Dr. Aneil Malhotra of the University of London. He did, however, comment that the study does not propose that screening is not worth the expense.

“Cynics would say perhaps screening is not effective because six of eight deaths were missed,” said Malhotra. But it could be argued that the heart problems which caused the deaths had not developed at the time of screening and “some may have displayed an abnormal ECG later on down the line.”

“This is very important and informs us that a one-off screen in an adolescent may not be sufficient and that serial assessments may be necessary,” the study’s senior author, Dr. Sanjay Sharma of the University of London, said in an email.

“These are elite-level soccer players” Malhotra said, so when all children who play soccer are included, “we think this is a minimum estimate of cardiac death. This is the tip of the iceberg.”