Mandatory Electrocardiographic Screening of Athletes to Reduce their Risk for Sudden Death:

1. Mandatory Electrocardiographic Screening of Athletes to Reduce their Risk for Sudden Death: Proven Fact or Wishful Thinking? ArieSteinvil, Tamar Chundadze, David Zeltser, OriRogowski, Amir Halkin, YairGalily, HaimPerluk, and Sami Viskin. Tel-Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University; Zinman College of Physical Education & Sports Sciences at the Wingate Institute; and Mediton Medical Center, Tel-Aviv, Israel. J Am Coll Cardiol 2011;57:1291-6

2. Background • Prevention of sudden death in athletes is a universal goal, but the optimal way to achieve this goal is still debated.1 • Nevertheless, an increasing number of countries and organizations, including the International Olympic Committee, are now mandating pre-participation screening of athletes including an electrocardiogram. • However, there is very limited proof that such preventive strategy actually works. 1References on debates: Viskin vs. Corrado: HeartRhythm 2007;4:520-4 and 525-8. Myerburg vs. Chaitman: Circulation 2007;116:2610-5 and 2616-26.

3. Present Study We analyzed the impact of the National Sport Law enacted in Israel in 1997 – which mandates screening of all athletes with resting ECG and exercise-testing – on the incidence of sudden death among competitive athletes. • Methods: • We conducted a systematic search of the two main newspapers in Israel to determine the yearly number of cardiac arrest events among competitive athletes. • The size of the population at risk was retrieved from the Israel Sport Authority and extrapolated to the changes in population-size over time. J Am Coll Cardiol 2011;57:1291-6

4. Results • We identified 24 events of sudden death or cardiac arrest in athletes. • All of them were males, aged 12-44 (23.9 ± 8.8) years and the majority were football (soccer) players. • Of these 24 events, 11 events occurred during the 12 years preceding the 1997 sports legislation mandating pre-participation screening and 13 occurred during the 12 years that followed. J Am Coll Cardiol 2011;57:1291-6

5. Results: Average yearly incidence of sudden death or cardiac arrest among athletes: Before screening = 2.54 p = 0.88 After screening = 2.66 Assuming that the proportion of inhabitants who engage in sports doubled over the last two decades Before screening = 4.27 p = 0.44 After screening = 3.13 J Am Coll Cardiol 2011;57:1291-6

6. Sudden death/cardiac arrest events rates in Israel per 100,000 athlete-years from 1985 to 2008. The crude rates are depicted by the solid line. The dotted line depicts our results after assuming that the percentage of the population actively participating in competitive sport gradually doubled during the last two decades J Am Coll Cardiol 2011;57:1291-6

7. Annual incidence of sudden cardiac death expressed per 100,000 person-years in the 3 studies evaluating the effects of screening on the mortality of athletes over time. The Italian study2 (pink) concluded that ECG screening (started in 1982) significantly reduced the incidence of sudden death by comparing sudden death rates in the 2-years pre-screening period (Point A to B) to the post-screening period (B to F). The present study (green) compared the 12 years before screening (C to E) to the 12 years after the onset of mandatory ECG screening (E to G). Had we limited our comparison of the post-screening period to the 2-year period preceding the enforcement of screening in Israel (D to E vs. E to G) (as performed in the Italian study) we would have erroneously concluded that screening saved lives of athletes. A Minnesota study3 (yellow) shows a low mortality rate in a population of athletes not undergoing systematic ECG screening. 2Corrado, JAMA 2006;296:1593 3Maron, Am J Cardiol 2009;104:276.

8. Limitations • This is a retrospective study. The same limitation applies to previous studies. • Due to the small number of events, the observed non-significant difference could be a β-type error. • It is possible that under-reporting of sudden deaths among athletes led to under-estimation of their sudden death risk. However, there is no reason to believe that under-reporting varied during the different years of the study period. Also, the sudden death rates in Israel are within the range reported by others. • The number of athletes was known for the end of the study-period but was estimated for the preceding years. This assumption could have led to errors when estimating the population at risk. • Because of possible inherent shortcomings of the screening process in Israel, our results cannot be extrapolated to other countries. J Am Coll Cardiol 2011;57:1291-6

9. Conclusions • In this retrospective study, mandatory screening of athletes with resting electrocardiogram and exercise effects had no apparent effect on the yearly cardiac-arrest event-rates among competitive athletes. • Importantly, had we limited our comparison of the post-screening period to the 2-year period preceding the enforcement of screening in Israel (as performed in the Italian study) we would have erroneously concluded that screening saved lives of athletes. J Am Coll Cardiol 2011;57:1291-6