New Study Shows Very Few Student-Athletes Survive SCA: Interview with Lead Author Jonathan A. Drezner, MD

A new study shows that from January 2000 to December 2006, survival following exercise-related SCA in young student-athletes was low — in fact, overall survival was only 11% (4-21% survival per year).1 In this article, we speak with Dr. Jonathan Drezner from the Department of Family Medicine at the University of Washington in Seattle, about these significant findings. His research appeared in the HeartRhythm Journal, the official journal of the Heart Rhythm Society. When you write that “there was a statistically significant trend toward improved survival in more recent years,” were you referring only to the later part of the study period? The data is only for the study period. In the last few years, survival has been greater than in the earlier years that we monitored in this study. It doesn’t refer to anything beyond the study period. The reason I ask is because I also read the media reports every day, and for a long time it seemed there were so many sudden cardiac deaths reported; however, in the last year there have been more stories of survival, I believe due to AEDs and increased SCA recognition. Yes, isn’t that great? I think your observation is correct. In our ongoing research using the National Registry for AED Use in Sports (www.aedsports.com), we’ve been trying to follow these cardiac arrests in a more scientific fashion so we have a better idea of survival rates and what factors play a role in predicting survival if a student-athlete experiences a cardiac arrest. What we found is that if you isolate the schools that have AEDs, particularly the high schools, we’re seeing a survival rate that is over 60 percent. This particular study that we just published is a look back over all the data from the last 7 years. It has some limited methodology in terms of how we collected the cases, but really, I think it speaks loudly that overall survival has generally been poor. There may have been a little trend towards improved survival recently, which is probably because AEDs are becoming more commonplace, although we couldn’t statistically demonstrate this in our study. In a different ongoing study, we analyzed survival rates at about 1,700 U.S. high schools over a 1-year period, and the overall survival rate for both students and non-students on campus who experienced SCA was 64%. Therefore, the message to me was pretty obvious: if there is an AED on school grounds with an appropriate emergency plan along with it, one can dramatically improve survival from an out-of-hospital cardiac arrest. That is what we would expect; the past studies on public access defibrillation and AED use all demonstrate survival rates of over 50 percent. Were you surprised by the study findings? I was surprised that the survival rate was as low as it was. These were otherwise young, healthy children and adolescents who did not have multi-symptom disease, such as many of the adults who have heart problems. Therefore, you hope that maybe the survival rate would have been a little higher. It was disappointing. Describe your study results. How many cases of SCA were there? There were 521 cases of sudden death identified in media reports; later when we reviewed those media reports, some were excluded because they were not cardiac in origin. In total there were 486 cases of heart-related sudden cardiac arrest that we analyzed. However, even within that category, the media reports were broken down into cases where the heart etiology of their cardiac arrest was confirmed or clearly described as a cardiac-related event, while others were more suggested due to details of the media report. Throughout the study we analyzed all of those statistics based on the total groupings of 486 as well as the breakdown between those that were confirmed cardiac and those who were presumed cardiac, and they were always the same — there were no differences between those groups. Why do you think such a higher percentage (83%) of sudden cardiac deaths were in males? The finding that females were more likely to survive SCA than males deserves more research and some follow up. Unfortunately, I do not have a good explanation as to why females were more likely to survive than males; it is possible but not at all supported by the information we have from this study that the etiology of the females’ arrest is different than that occurring in males, and therefore possibly more easily or successfully resuscitated. However, that is simply one potential hypothesis and it is not supported by the data we have. Males in general, though, have been found in multiple studies to have a higher incidence of SCA than females; in our study the ratio was 5:1 and in many others the ratio has been 9:1. I see that most SCAs took place at the high school level. Could this finding lead the effort to promote more preparticipation ECG screenings in student-athletes? Absolutely. The current recommendation from the American Heart Association is for sports preparticipation screening to begin at age 12, which would cover certainly those competitive athletes before they enter high school. I am pretty sure every high school in the United States requires that their athletes receive a preparticipation physical upon entry to high school and then every 2 years after that, with a follow up in interval years. They should be getting at least a history questionnaire for new symptoms, which can be evaluated by a physician if needed. I think the reason that the majority of these cases were in the high school age group is partly because this higher age group represents the largest number of competitive athletes. There are some diseases such as hypertrophic cardiomyopathy that often do not manifest themselves until adolescence or maturity, so some of those disorders become more common during a later age. Tell us about the Sudden Death In Young Athletes national registry. Dr. Barry Maron, who runs the Sudden Death In Young Athletes registry, is one of the world’s experts in sudden cardiac death in young athletes. He has been monitoring cases of SCA for over two decades in the U.S. through the best available search mechanisms. He analyzes available electronic resources and media reports and then follows up on those cases. The numbers that they’re finding in recent years have really shed light on the estimated incidence of SCD in young athletes — the prior estimate of 1 in 200,000 really underrepresents the magnitude of the problem. It is actually more like 1 in 50,000 — about 4 times higher than some traditional estimates. To the credit of Dr. Maron, he has brought this issue to the forefront. What has been the response to this research from advocacy groups? I’m not sure what the response from the advocacy groups has been. I imagine that they would have thought SCA was more common than had previously been published. Personally I try to stay away from terms such as ‘rare’ and ‘infrequent’ that have been used to describe the incidence of sudden death in athletes, because I think they give the connotation that because it’s so ‘rare’ you can look the other way and not address the issue. The truth is that both our data collection system and our method for monitoring these cases are extremely limited in the United States. We do not have a mandatory reporting system for juvenile sudden death, and that is very unfortunate, because it makes understanding the magnitude of the problem very difficult: how else do you capture all the cases of cardiac arrest in that age group? Media reports certainly do not cover all of the cases. Therefore, how do you really understand what the true denominator is for athletes who experience cardiac arrest? I imagine that most people who critically look at our traditional estimates in the U.S. interpret their studies based on the methodology used, so it’s not too much of a surprise to me that the incidence is higher than what we had found before using non-mandatory reporting systems. For mandatory reporting systems in other populations, the incidence is much higher. For example, in one study by Eckart2 published in 2004 in the Annals of Internal Medicine, the yearly incidence of sudden cardiac arrest in U.S. military recruits (mean age of 19) was 1 in 9,000. In addition, if you look at studies from Italy, where there is a mandatory reporting system for juvenile sudden death, the incidence of sudden death in their athletes was 1 in 25,000 (mean age of 24) before implementing a national screening program.3 Therefore, to assume that in the United States our incidence is only 1 in 200,000 means cases are being missed. Describe the mandatory reporting system that you would like to see created. Would it be similar to Italy’s program? That is a really good and also difficult question. It is something that we have thought a lot about. I think the starting point is to create, through state and federal collaboration, a registry for juvenile sudden death, or at a minimum, sudden cardiac death. So for every case of someone younger than 25 or whichever age group you want to identify, there would be a forensic study, and that information would be sent to a central agency that could tabulate the findings and the results. We would then receive information on the medical causes of death in that particular age group, and we could pull out the cardiac-related ones and look at just those. However, by gaging a registry on only forensic information, then you’re only capturing information on the deaths and not on SCA events. Through the National Registry for AED Use in Sports, we have tried to monitor a population of high schools over time and understand what the incidence is, but again, it is very difficult to capture all the cases. If we had a central, national registry for juvenile sudden cardiac death, we would gain a wealth of information that would be helpful in preventing these catastrophes. Are you hopeful that changes will take place? Yes, I am hopeful. However, I am not really sure who might take ownership or take the lead in developing or funding such changes. I do remain optimistic that at some point this might happen, but it will take leadership from both the medical community as well as policymakers. Of course, it will also depend on funding. Will further research be done? Through continued collaboration with Parent Heart Watch, when media reports surface on new case reports of SCA in student-athletes, we try to contact someone involved in the resuscitation, to understand more details about the event and to get a better idea of what factors might predict survival. For instance, we ask: • Was it a witnessed arrest? • Was there someone there who was trained in CPR? • Was CPR initiated? • Was there an AED nearby? • What was the timing from collapse to defibrillation? These are factors we are trying to monitor to show in our ongoing research what a dramatic difference it makes when an AED is available. Should students also be involved in AED advocacy and SCA awareness? That would be a wonderful goal to have — it is our next-level objective of SCD prevention. The first objective, of course, is to ensure that every school has at least one AED on school grounds and that every school has trained coaches in CPR and AED use as well as other trained first responders (such as school nurses, school security, or athletic trainers). Schools should also have an organized emergency plan in case a student or student-athlete collapses. In addition to that, if we can incorporate CPR and AED training into health and wellness classes for students, and make some graduation recommendations for every high school student to complete CPR and AED training, that would produce a more knowledgeable and somewhat safer population for years to come. Many high schools already have initiated such classes. It might also help students to understand why an AED is publicly available in their school hallways and gymnasium, and also possibly decrease vandalism of this equipment. Do you think that sudden cardiac arrest occurrences are increasing, or are these occurrences just more frequently reported? I believe people are just becoming more aware of it. I don’t think the true incidence or prevalence of the problem has increased — we are just becoming better at detecting the cases. Is there anything else you’d like to add? I hope this study will begin to help all of us understand how to prevent SCD in young athletes, improve the poor survival rate and ensure AED use and emergency planning in schools. For more information, please visit: http://www.heartrhythmjournal.com/article/S1547-5271(08)00235-X/fulltext