This year's American Heart Association Scientific Sessions (AHA 2023) in Philadelphia featured several sessions dedicated to exercise and sports cardiology, including an expert-led session on sudden cardiac arrest (SCA) on the athletic field and two major sports cardiology studies.

Cardiac Arrest on the Athletic Field: A Team Approach

This much-anticipated Main Event session featured moving, personal accounts from athlete survivors of SCA: Messrs. Omar Carter and Nick Knapp (Figure 1). Additionally, expert faculty led the audience through reviews on the key pieces of addressing SCA in athletes.

Block and Tackle: Cardiac Arrest on the Field

Dr. Jonathan Kim introduced the epidemiology and etiology of SCA in athletes, as well as the utility of preparticipation screening (PPS) and importance of emergency action plans (EAP). He emphasized the incidence of SCA in athletes and its unequal distribution along the lines of race, sports type, and biological sex (highest in self-identified blacks, basketball, males), while acknowledging the limitations of the available data and the fallacy of race-based medicine. The etiology of SCA may be secondary to structural, electrical, or acquired heart disease (i.e., myocarditis, trauma). While SCA in younger athletes is frequently attributed to autopsy negative sudden unexplained death (SUD) and hypertrophic cardiomyopathy (HCM), masters athletes are susceptible to ischemia related SCA. Dr. Kim noted that not all cases of SCA are preventable by PPS and that effective EAPs are our best insurance to surviving SCA on the athletic field/event.

Full-Court Press: Emergency Preparedness

Dr. Benjamin Levine began by discussing the variation in practice and imperfections inherent with PPS. While debate around the utility of PPS exists, there is no debate over the necessity of strong, widespread EAPs. Dr. Levine outlined the crucial components of an effective EAP, emphasizing the importance of a collaborative effort involving all stakeholders, and that the EAP should be rehearsed, edited, displayed, and appropriately distributed. Dr. Levine reviewed recent data suggesting that availability of bystander cardiopulmonary resuscitation (CPR) and on-site automated external defibrillators (AEDs) most effectively improve survival after SCA on the athletic field. He closed after highlighting the Smart Heart Sports Coalition's three best practice policies for maximizing survival after SCA: an EAP, coaches trained in CPR, and nearby, clearly marked AEDs.

A Sticky Wicket: Return to Play

Dr. Rachel Lampert addressed the complex decision of athletes returning to play post-SCA. She described the launch of the implantable cardioverter-defibrillator (ICD) Sports Registry that allowed for the prospective study of 440 athletes with ICDs who had returned to play after SCA.^1,2 While many athletes received shocks (appropriate and inappropriate, during sports and at rest) after a median follow-up time of 44 months, there were no failures to defibrillate or injury due to arrhythmia or shock during sports. The majority of patients who received defibrillation decided to return to play, suggesting a quality-of-life benefit conferred by sports participation. From this backdrop, Dr. Lampert closed with a discussion of the paradigm shift toward shared decision-making models with individualized risk/benefit assessments.

Running Interference: To Screen or Not to Screen

Dr. Meagan Wasfy tackled the topic of PPS. Young athletes are at relatively higher risk for SCA and are the primary target for PPS. One challenge in effective screening is the task of detecting a multitude of potential diagnoses with basic diagnostic tools. Dr. Wasfy noted the poor diagnostic performance of the preparticipation history and physical (H&P) and discussed the role of electrocardiogram (ECG) in PPS. Once the ECG interpreter is familiar with the electrocardiographic changes in normal athletes, ECG can improve the diagnostic performance of PPS when combined with a targeted H&P. However, ECG has not been proven to reduce SCA in the United States and the resources to implement ECG screening are not available in all scenarios. She closed by emphasizing the importance of reserving resources for strong EAPs.

Further, two major sports cardiology studies were presented at the meeting: the 20-year follow-up of SCA in National Collegiate Athletic Association (NCAA) athletes and the Lifestyle and Exercise in Long QT Study (LIVE-LQTS).

Incidence and Causes of Sudden Cardiac Death (SCD) in NCAA Athletes: A 20-year Study

Dr. Bradley Petek presented the updated incidence and causes of sudden cardiac death (SCD) in NCAA athletes spanning from 2002-2022. Led by senior investigator Dr. Kim Harmon, this multicenter retrospective study of Division I, II, and III NCAA athletes utilized four unique databases to identify student deaths. There were 1,102 deaths over 9.1 million athlete-years, of which SCD (n=143, 13%) was the most common medical cause with an overall incidence of SCD of one in 64,000 athletes. Autopsy-negative SUD (19%) followed by HCM (13%) were the most common causes of SCD. Notable disparities were uncovered: male athletes had a higher incidence of SCD than female athletes (one per 43,348 vs. 164,504 athlete-years), while black athletes had a higher incidence than white athletes (one per 26,704 vs. 74,581 athlete-years). Basketball, followed by American football, was the highest risk sport. Rates of SCD fell by approximately 70% over the entire study period. The cause for this decrease in SCD is not clear but it has been proposed that improved PPS and more widespread EAP/AED use may be potential factors.

LIVE-LQTS

Dr. Lampert presented the LIVE-LQTS, evaluating whether vigorous exercise, including competitive sports, was associated with increased life-threatening ventricular arrhythmias and/or mortality in long QT syndrome (LQTS). This was a prospective study of 1,413 individuals with manifest or concealed LQTS from 42 sites in five countries. Most (52%) were >25 years old, 35% were 18-25 years old, and 13% were <18 years old. The majority were white (93.9%) and female (67%). The bulk of patients were cared for at high volume centers and >80% were on beta-blockers. Vigorous exercise was defined as at least one activity with metabolic equivalents (METS) ≥6 for ≥60 hours per year (52% of the cohort). Follow-up consisted of surveys every 6 months for 3 years with endpoints of death, resuscitated cardiac arrest, syncope (definitely/likely arrhythmic, undetermined), or appropriate ICD shock. There was no significant difference in composite endpoints between vigorous and non-vigorous exercisers (2.6% vs. 2.7% respectively) even among highly competitive athletes. In contrast to historical guidelines, this study suggests competition and vigorous exercise are safe in patients with LQTS who have been evaluated and treated in expert centers.

References

1. Lampert R, Olshansky B, Heidbuchel H, et al. Safety of sports for athletes with implantable cardioverter-defibrillators: results of a prospective, multinational registry. Circulation 2013;127:2021-30.
2. Lampert R. Sport participation in patients with implantable cardioverter-defibrillators. Curr Treat Options Cardiovasc Med 2019;21;66.