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Outcomes of Athletes With Genetic Heart Diseases and Implantable Cardioverter-Defibrillators Who Chose to Return to Play

  • Kathryn E. Tobert
    Affiliations
    Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN, USA
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  • J. Martijn Bos
    Affiliations
    Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN, USA
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  • Bryan C. Cannon
    Affiliations
    Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, MN, USA

    Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, MN, USA
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  • Michael J. Ackerman
    Correspondence
    Correspondence: Address to Michael J. Ackerman, MD, PhD, Mayo Clinic Windland Smith Rice Genetic Heart Rhythm Clinic and the Windland Smith Rice Sudden Death Genomics Laboratory, Guggenheim 501, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 USA.
    Affiliations
    Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN, USA

    Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, MN, USA

    Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, MN, USA
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      Abstract

      Objective

      To evaluate outcomes for athletes with a genetic heart disease (GHD) and an implantable cardioverter-defibrillator (ICD) after return-to-play (RTP) approval.

      Patients and Methods

      We conducted a retrospective review of athletes with GHD and an ICD who were evaluated and treated in Mayo Clinic’s Genetic Heart Rhythm Clinic between July 2000 and July 2020. Data on frequency of GHD-associated breakthrough cardiac events (BCEs), inappropriate shocks, and ICD-related complications were collected and analyzed.

      Results

      There were 125 (57 [45.6%] female) GHD-positive athletes with an ICD (mean age at RTP was 19.8±11.6 years); 56 of 125 (44.8%) had long QT syndrome. Overall, 42 ventricular fibrillation–terminating ICD therapies were given to 23 athletes (18.4%) over an average follow-up of 3.6±3.5 years. Athletes with an ICD were more likely to experience a BCE during athletic follow-up (n=28 of 125, 22.4%) compared with those without an ICD (n=4 of 533, 0.8%; P<.0001). The BCE rate for athletes with ICDs was 6.3 events per 100 athlete-years of follow-up; this included 5.1 ventricular fibrillation–terminating events per 100 athlete-years compared with 0.3 BCEs per 100 patient-years for athletes without ICDs. In total, 6 (4.8%) athletes experienced at least one inappropriate shock (1.34 per 100 athlete-years) and 28 (29.6%) athletes had at least one other device-related complication (5.02 per 100 patient-years). However, none of these other complications occurred during sports.

      Conclusion

      This 20-year single-center study provides the longest spanning retrospective review of outcomes for athletes with ICDs given RTP approval. For athletes with GHD and an ICD, no sports-associated deaths or reports of sports-related ICD damage occurred.

      Abbreviations and Acronyms:

      ARVC (arrhythmogenic right ventricular cardiomyopathy), BCE (breakthrough cardiac event), CPVT (catecholaminergic polymorphic ventricular tachycardia), GHD (genetic heart disease), HCM (hypertrophic cardiomyopathy), ICD (implantable cardioverter-defibrillator), LQTS (long QT syndrome), RTP (return to play), SCA (sudden cardiac arrest), SCD (sudden cardiac death), SDM (shared decision making), VF (ventricular fibrillation), VT (ventricular tachycardia)
      Implantable cardioverter-defibrillators (ICDs) and competitive sports participation have long existed as an oxymoron. In general, sudden cardiac death (SCD)–predisposing genetic heart diseases (GHDs) include the inherited cardiomyopathies and channelopathies. Cardiac channelopathies, such as long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and Brugada syndrome, are caused by pathogenic variants in one of the cardiac ion channel–encoding genes which ultimately affect the cardiac action potential. Cardiomyopathies, such as hypertrophic cardiomyopathy (HCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC), are characterized by structural changes in the heart tissue.
      Frequently, athletes with a GHD are disqualified from competitive sports participation because of a perceived risk of sudden cardiac arrest (SCA) or SCD during sports. In addition, athletes with ICDs have been disqualified from competitive sports because of the perception of greater risks associated with device malfunction, damage to the device, or injury to the athlete. In 2005, at the 36th Bethesda Conference, an expert task force created guidelines and recommendations for competitive athletes with an array of cardiovascular abnormalities.
      • Maron B.J.
      • Zipes D.P.
      Introduction: Eligibility recommendations for competitive athletes with cardiovascular abnormalities—general considerations.
      These guidelines recommended disqualification from most competitive sports for the athlete with an ICD, restricting the athlete to participation in only class IA sports (billiards [subsequently removed and replaced with yoga], bowling, cricket, curling, golf, and riflery). These recommendations were given out of an abundance of precaution and these guidelines were created without any observational data to support these recommendations.
      • Maron B.J.
      • Zipes D.P.
      Introduction: Eligibility recommendations for competitive athletes with cardiovascular abnormalities—general considerations.
      In 2013, Lampert et al
      • Lampert R.
      • Olshansky B.
      • Heidbuchel H.
      • et al.
      Safety of sports for athletes with implantable cardioverter-defibrillators: results of a prospective, multinational registry.
      published the initial outcomes of a multicenter study comprised of 372 competitive athletes with a variety of cardiac diseases and ICDs who were prospectively followed while participating in organized and high-risk sports. This study was the first to show that an athlete with an ICD can safely participate in competitive sports with minimal risk of injury to the athlete or failure of the device to terminate a potentially lethal arrhythmia. Further, the favorable outcomes of this study ultimately catalyzed a guideline update for athletes with an ICD in 2015 by the American College of Cardiology and the American Heart Association.
      • Zipes D.P.
      • Link M.S.
      • Ackerman M.J.
      • Kovacs R.J.
      • Myerburg R.J.
      • Estes 3rd, N.A.M.
      Eligibility and disqualification recommendations for competitive athletes with cardiovascular abnormalities: task force 9: arrhythmias and conduction defects: a scientific statement from the American Heart Association and American College of Cardiology.
      ,
      • Zipes D.P.
      • Link M.S.
      • Ackerman M.J.
      • Kovacs R.J.
      • Myerburg R.J.
      • Estes 3rd, N.A.
      Eligibility and disqualification recommendations for competitive athletes with cardiovascular abnormalities: task force 9: arrhythmias and conduction defects: a scientific statement from the American Heart Association and American College of Cardiology.
      These guidelines, although still restrictive, now allowed athletes who had been ICD shock-free for 3 months to participate in sports, although they were still restricted to solely to the aforementioned class IA sports. However, the guidelines newly introduced the potential to participate in higher-intensity sports if the athlete was properly risk stratified and counseled on the risks associated with return-to-play (RTP).
      • Zipes D.P.
      • Link M.S.
      • Ackerman M.J.
      • Kovacs R.J.
      • Myerburg R.J.
      • Estes 3rd, N.A.M.
      Eligibility and disqualification recommendations for competitive athletes with cardiovascular abnormalities: task force 9: arrhythmias and conduction defects: a scientific statement from the American Heart Association and American College of Cardiology.
      ,
      • Zipes D.P.
      • Link M.S.
      • Ackerman M.J.
      • Kovacs R.J.
      • Myerburg R.J.
      • Estes 3rd, N.A.
      Eligibility and disqualification recommendations for competitive athletes with cardiovascular abnormalities: task force 9: arrhythmias and conduction defects: a scientific statement from the American Heart Association and American College of Cardiology.
      Subsequently, in a follow-up study on the same prospective ICD athlete cohort from 2013, Saarel et al
      • Saarel E.V.
      • Law I.
      • Berul C.I.
      • et al.
      Safety of sports for young patients with implantable cardioverter-defibrillators: long-term results of the multinational ICD sports registry.
      showed that, although there was still a risk of ventricular tachycardia (VT)/ventricular fibrillation (VF)–terminating ICD shocks with continued sports participation, there was no indication of adverse sequelae following such an event.
      Based on our initial studies involving all of our athletes with a GHD who returned to play,
      • Tobert K.E.
      • Bos J.M.
      • Garmany R.
      • Ackerman M.J.
      Return-to-play for athletes with long QT syndrome or genetic heart diseases predisposing to sudden death.
      • Johnson J.N.
      • Ackerman M.J.
      Competitive sports participation in athletes with congenital long QT syndrome.
      • Johnson J.N.
      • Ackerman M.J.
      Return to play? Athletes with congenital long QT syndrome.
      we performed a substudy analysis of those GHD-positive athletes with an ICD. Herein, we provide the longest-spanning retrospective review of these athletes who were given a formal RTP approval by a single genetic cardiologist (MJA) in Mayo Clinic’s Windland Smith Rice Genetic Heart Rhythm Clinic to evaluate their outcomes and complications.

      Patients and Methods

      After obtaining Institutional Review Board approval, we retrospectively reviewed all GHD athletes who had received RTP approval at Mayo Clinic’s Windland Smith Rice Genetic Heart Rhythm Clinic between July 2000 and July 2020.
      • Tobert K.E.
      • Bos J.M.
      • Garmany R.
      • Ackerman M.J.
      Return-to-play for athletes with long QT syndrome or genetic heart diseases predisposing to sudden death.
      From within this cohort, we performed a substudy analysis of those GHD-positive athletes whose treatment program included an ICD. All patients were evaluated and treated by a single genetic cardiologist and given a formal RTP approval following comprehensive risk stratification, treatment optimization, and shared decision making (SDM). An athlete was defined as an individual who participated in organized competitive sports. During follow-up, if an athlete discontinued organized sports participation (not as a result of their GHD diagnosis) but continued frequent aerobic activity, they were considered an athlete at that time. The RTP-ICD period was defined as being the period of time after RTP approval was given (if the athlete already had an ICD in place at RTP) or the date at which the athlete who was previously given RTP approval received their ICD, until the last documentation of athletic participation in the electronic medical record.
      The goal of this study was to evaluate outcomes, breakthrough cardiac events (BCEs), and ICD-related complications during the RTP-ICD period for all athletes with an ICD who chose to RTP. All clinical details, including detailed information on BCEs were abstracted from the electronic medical record, and subsequently, event rates were calculated and corrected to events per 100 patient-years of follow-up. A BCE was defined as either 1) a GHD-associated symptomatic episode (syncope or presyncope, chest pain, palpitations, or shortness of breath) with nonsustained arrhythmia(s) recorded by the ICD at that time; 2) an appropriate VT/VF-terminating ICD therapy; or 3) SCD. To provide insight on the differences in event rates during and outside of sports participation, BCEs were classified as occurring during the athletic period (represented as athlete-years), or before or after sports participation began or ended (represented as patient-years). Event rates were calculated for each of these follow-up periods. This BCE rate for the athletes with GHD and an ICD was compared to the much larger cohort of GHD athletes who were treated without an ICD.
      Details on ICD-related complications were collected. Device-related complications were classified as manufacturer recall, damage (eg, lead fracture), or secondary complications (eg, pocket infection/hematoma or postoperative pain). Additionally, details on inappropriate shocks were collected and, similarly, this shock rate was calculated and presented as an event rate per 100 patient-years.
      For the past 10 years, under guidance from one of our pediatric heart rhythm specialists (BCC), the same standard protocol has been used for each patient who receives an ICD at Mayo Clinic, irrespective of whether they are an athlete. In general, for these patients we use a higher detection rate and longer detection time when initially programming the device. For monitoring, we use a 200 to 220 beats/min zone, 220 to 240 beats/min for the therapy zone (antitachycardia pacing is attempted here, and the arrhythmia is diagnosed as being supraventricular tachycardia or VT), and greater than or equal to 240 beats/min for the VF zone. Given the individualized nature of treatment in patients with the various GHDs represented, these parameters can fluctuate or be further tailored in a patient- and GHD-guided manner and are re-evaluated should a patient receive an inappropriate shock caused by supraventricular tachycardia or lead fracture.
      Lastly, athletes were classified by the primary sport that they participated in using the original Bethesda system of classification.
      • Maron B.J.
      • Zipes D.P.
      Introduction: Eligibility recommendations for competitive athletes with cardiovascular abnormalities—general considerations.
      The Bethesda system of classification categorizes sports by their primary “static” and “dynamic” components. Activities with higher static and/or dynamic components are associated with greater adrenergic stimulation and are of potentially higher risk. For athletes who participated in more than one sport, the sport with the highest static and/or dynamic component was considered the patient’s primary sport. When a tie between static and dynamic components occurred, the activity with the highest dynamic component was used in their assignment (ie, an athlete participating in a class IIC sport and a class IIIB sport was designated as a class IIC-sport participant). Those who participated in cheerleading or dance were classified as IIIA-sport athletes due to the high static component of these sports (similar to martial arts or gymnastics).

      Statistical Analyses

      Statistically significant differences for event rates were assessed using a Poisson regression analysis. This type of analysis is used for discrete events which occur in a fixed time interval, and the P value represents the statistical significance between two different event rates.
      • Frome E.L.
      The analysis of rates using Poisson regression models.
      Confidence intervals were calculated for the event rates and added to these results, and were presented as event rate (95% CI, lower limit-upper limit) or as CI bars. Overall, P<.05 was considered statistically significant.

      Results

      From July 2000 to July 2020, 672 athletes with a GHD were evaluated, risk stratified, treated, and given a formal RTP approval by a single genetic cardiologist (MJA) in the Mayo Clinic Windland Smith Rice Genetic Heart Rhythm Clinic (Figure 1A). From the entire previously published cohort,
      • Tobert K.E.
      • Bos J.M.
      • Garmany R.
      • Ackerman M.J.
      Return-to-play for athletes with long QT syndrome or genetic heart diseases predisposing to sudden death.
      139 had an ICD as part of their GHD-directed treatment and SCD prevention plan. Subsequently, 14 of 139 GHD/ICD-positive patients (10.1%) were excluded from the analyses because they were lost to follow-up after ICD implantation or RTP approval. As such, this substudy analysis was comprised of 125 GHD-positive athletes with an ICD who had adequate follow-up and participated in competitive sports following RTP approval and ICD placement (Figure 1A).
      Figure thumbnail gr1
      Figure 1Cohort breakdown. From July 2000 until July 2020, 672 athletes with genetic heart disease (GHD) were given return-to-play (RTP) approval in the Mayo Clinic Windland Smith Rice Genetic Heart Rhythm Clinic. In total, 139 GHD athletes had an implantable cardioverter-defibrillator (ICD) implanted during their follow-up. The study cohort was comprised of 125 GHD/ICD-positive athletes who had sufficient follow-up during their RTP-ICD period. B, Breakdown of breakthrough cardiac events (BCEs). Of the 125 GHD-positive athletes who had an ICD, 28 (22.4%) had greater than or equal to one BCE during their RTP-ICD period. Of these, 15 (12.0%) had greater than or equal to one BCE while playing sports, and 13 (10.4%) had greater than or equal to one BCE during non–sports-related activities. All BCEs that occurred outside of the RTP period were non-sports relad.
      Demographics for this GHD/ICD study cohort are summarized in Table 1. Overall, 57 of 125 (45.6%) athletes with an ICD were female and 56 of 125 (44.8%) had LQTS. The other GHDs represented in this cohort included 22 with HCM (17.6%), 17 with CPVT (13.6%), 15 with idiopathic ventricular fibrillation (IVF) (12.0%), and 8 with ARVC (6.4%). The average age at ICD placement was 19.1±10.6 years, and the average age at RTP was 19.8±11.6 years. Overall, 73 (58.4%) athletes were symptomatic before diagnosis, 77 (61.6%) had a family history of their specific GHD, and 52 (41.5%) had a family history of SCD. In total, only 8 patients (6.4%) had a subcutaneous ICD, none of whom experienced sports-related damage or BCEs during follow-up.
      Table 1Demographics of Athletes With ICDs
      ABiMVPS = arrhythmogenic bileaflet mitral valve prolapse syndrome; ARVC = arrhythmogenic right ventricular cardiomyopathy; BCE = breakthrough cardiac event; BrS = Brugada syndrome; CPVT = catecholaminergic polymorphic ventricular tachycardia; DCM = dilated cardiomyopathy; GHD = genetic heart disease; HCM = hypertrophic cardiomyopathy; ICD = implantable cardioverter defibrillator; IVF = idiopathic ventricular fibrillation; LQTS = long QT syndrome; RTP = return to play; SCD = sudden cardiac death; VT = ventricular tachycardia.
      ,
      Values are n (%) unless otherwise stated.
      N125
      Sex, male/female68/57
      Average age at ICD placement, y19.1±10.6
      Average age at RTP, y19.8±11.6
      Patients with BCE34 (27.2)
      Diagnosis
       LQTS56 (44.8)
       HCM22 (17.6)
       CPVT17 (13.6)
       IVF15 (12.0)
       ARVC8 (6.4)
       ABiMVPS3 (2.4)
       BrS2 (1.6)
       Catecholamine-sensitive VT1 (0.8)
       DCM1 (0.8)
      Family history of GHD77 (61.6)
      Family history of SCD52 (41.6)
      Symptomatic before diagnosis73 (58.4)
      Total RTP-ICD-years of follow-up, y447.3
      Average RTP-ICD-years of follow-up, y3.6±3.5
      a ABiMVPS = arrhythmogenic bileaflet mitral valve prolapse syndrome; ARVC = arrhythmogenic right ventricular cardiomyopathy; BCE = breakthrough cardiac event; BrS = Brugada syndrome; CPVT = catecholaminergic polymorphic ventricular tachycardia; DCM = dilated cardiomyopathy; GHD = genetic heart disease; HCM = hypertrophic cardiomyopathy; ICD = implantable cardioverter defibrillator; IVF = idiopathic ventricular fibrillation; LQTS = long QT syndrome; RTP = return to play; SCD = sudden cardiac death; VT = ventricular tachycardia.
      b Values are n (%) unless otherwise stated.
      During a total of 447.3 RTP-ICD-years of follow-up, 28 athletes (22.4%; 6.26 [95% CI, 4.2 to 9.0] events per 100 athlete-years) had greater than or equal to one BCE during their RTP-ICD period. Of these, 15 (53.6%; 3.35 [95% CI, 1.9 to 5.5] events per 100 athlete-years) had greater than or equal to one sports-related BCE, and 13 (46.4%; 2.91 [95% CI, 1.5 to 5.0] events per 100 athlete-years) had greater than or equal to one non–sports-related BCE (Figure 1B). During the RTP period, 23 athletes (18.4%; 5.14 [95% CI, 3.3 to 7.7] shocks per 100 athlete-years) experienced a total of 42 appropriate shocks (mean: 1.83 shocks per athlete), whereas another five athletes (4.0%; 1.12 [95% CI, 0.36 to 2.6] events per 100 athlete years) experienced a total of 5 syncopal events without a shock but with recorded nonsustained VT; two athletes (1.6%; 0.45 [95% CI, 0.05 to 1.6] events per 100 athlete-years) experienced an ICD storm. On the other hand, six patients (4.8%; 5.42 [95% CI, 2.0 to 11.8] events per 100 patient-years) experienced a BCE outside of their RTP period with all events occurring during non–sports-related activities (Figure 1B). These six athletes experienced one BCE each (five with appropriate ICD shocks, one with an ICD storm).
      As expected, and as a result of appropriate risk stratification, athletes with ICDs were significantly more likely to experience a BCE during their RTP period when compared with the larger GHD athlete cohort without ICDs evaluated and treated during the same study period (n=533; part of our overall, recently published cohort
      • Tobert K.E.
      • Bos J.M.
      • Garmany R.
      • Ackerman M.J.
      Return-to-play for athletes with long QT syndrome or genetic heart diseases predisposing to sudden death.
      ) (n=28 [22.4%] vs n=4 [0.8%], respectively) As a result, the difference in event rate per 100 athlete-years of follow-up between groups was significantly different (6.26 for athletes with an ICD vs 0.31 for athletes without an ICD; P<.0001) (Figure 2). Overall, there was no statistically significant difference in event rates between specific GHDs in athletes with an ICD (P=.65) nor for athletes without an ICD (P=.30) (Figure 3).
      Figure thumbnail gr2
      Figure 2Classification of primary sport among athletes with GHD and an ICD. Sports were classified based on their “static” and “dynamic” components. Athletes who participated in dance were considered class IIIA-sport athletes. The majority of athletes participated in class IIC and class IIIC sports, and 51 (40.8%) athletes participated in more than one sport. F = female; M = male; MVC = maximal voluntary contraction.
      Figure thumbnail gr3
      Figure 3Events per 100 patient-years in athletes with and without an implantable cardioverter-defibrillator (ICD). Event rates are presented with 95% CI bars. Overall, there was a statistically significant difference between event rates in athletes with and without ICDs (P<.0001). ARVC = arrhythmogenic right ventricular cardiomyopathy; CPVT = catecholaminergic polymorphic ventricular tachycardia; HCM = hypertrophic cardiomyopathy; LQTS = long QT syndrome.
      Overall, 99% of athletes participated in sports other than class IA sports, and class IIC and class IC were the most common categories for primary sport classification (Figure 2). In total, 51 (40.8%) athletes participated in more than one sport. There was no significant difference in event rates during sports participation across different sports classifications. The most common primary sports were basketball (24.6%), soccer (10.7%), and long distance running (8.2%, Table 2).
      Table 3Primary Sports
      Sports were classified using the Bethesda system of classification. The Bethesda system of classification categorizes sports by their primary “static” and “dynamic” components. For multi-sport athletes, the sport with the highest static and/or dynamic component was considered the primary sport. When a tie between static and dynamic components occurred, the activity with the highest dynamic component was assigned as the primary sport (ie, an athlete participating in a class IIC sport and a class IIIB sport was designated as a class IIC-sport participant). Cheerleaders and dancers were classified as IIIA-sport athletes due to the high static component of these sports (similar to martial arts or gymnastics).
      Primary SportsnBethesda classification
      Archery12A
      Backpacking11C
      Baseball51B
      Basketball302C
      Cheerleading23A
      Cross-country skiing11C
      Cycling23C
      Dance33A
      Diving12A
      Figure skating12B
      Football92B
      Gymnastics13A
      Ice hockey62C
      Lacrosse12C
      Long distance running101C
      Martial arts23A
      Rugby12B
      Running (sprint)22B
      Snowboarding13B
      Soccer131C
      Softball41B
      Swimming52C
      Tennis62C
      Triathlon43C
      Volleyball71B
      Weightlifting13A
      Wrestling13B
      Yoga11A
      a Sports were classified using the Bethesda system of classification. The Bethesda system of classification categorizes sports by their primary “static” and “dynamic” components. For multi-sport athletes, the sport with the highest static and/or dynamic component was considered the primary sport. When a tie between static and dynamic components occurred, the activity with the highest dynamic component was assigned as the primary sport (ie, an athlete participating in a class IIC sport and a class IIIB sport was designated as a class IIC-sport participant). Cheerleaders and dancers were classified as IIIA-sport athletes due to the high static component of these sports (similar to martial arts or gymnastics).
      In total, 37 athletes (29.6%) had greater than or equal to one device-related complication during follow-up for a total of 60 reported complications (6.63 per 100 patient-years; mean, 1.62 complications per athlete). More specifically, six patients (4.8%) had greater than or equal to one manufacturer recall, eight patients (6.4%) had greater than or equal to one device complication, and 17 patients (13.6%) suffered secondary complications following implantation or revision, all of which were treated and resolved without long-term side effect (Table 3). None of the damage or complications was directly related to any athletic activity.
      Table 2Complications and Inappropriate Shock Rates for GHD Athletes During Their RTP-ICD Period
      GHD = genetic heart disease; ICD = implantable cardioverter-defibrillator; RTP = return to play.
      ,
      Values are reported as n (%).
      Number of patients with ≥1 complication (including inappropriate shocks)37 (29.6)
       Device damage8 (6.4)
       Inappropriate shocks11 (8.8)
      Total number of reported complications60
      Total number of inappropriate shocks20
      Inappropriate shock rate per 100 RTP-ICD years1.34
      Average number of inappropriate shocks during RTP-ICD period1.83
       Manufacturer recall6 (4.8)
       Secondary complications17 (13.6)
      Epicardial perforation1
      Incomplete wound healing4
      Infection3
      Pericarditis3
      Pleural effusion3
      Postoperative pain3
      Significant edema2
      Thrombus3
      Tricuspid valve regurgitation1
      a GHD = genetic heart disease; ICD = implantable cardioverter-defibrillator; RTP = return to play.
      b Values are reported as n (%).
      In total, 11 patients (8.8%) experienced a total of 20 inappropriate shocks during follow-up; six patients (4.8%; 1.34 [95% CI, 0.5-2.9] events per 100 athlete-years) experienced greater than or equal to one inappropriate shock during their RTP-ICD period, and the remaining five patients (4.0%; 4.51 [95% CI, 1.5-10.5] events per 100 patient-years) experienced inappropriate shocks outside of their RTP-ICD period. On average, athletes received 1.83 inappropriate shocks during their RTP-ICD period.

      Discussion

      Until recently, all athletes with an ICD were confined to billiards, bowling, cricket, golf, and riflery (with billiards being exchanged for yoga recently
      • Maron B.J.
      • Zipes D.P.
      Introduction: Eligibility recommendations for competitive athletes with cardiovascular abnormalities—general considerations.
      ,
      • Zipes D.P.
      • Link M.S.
      • Ackerman M.J.
      • Kovacs R.J.
      • Myerburg R.J.
      • Estes 3rd, N.A.
      Eligibility and disqualification recommendations for competitive athletes with cardiovascular abnormalities: task force 9: arrhythmias and conduction defects: a scientific statement from the American Heart Association and American College of Cardiology.
      ,
      • Maron B.J.
      • Udelson J.E.
      • Bonow R.O.
      • et al.
      Eligibility and disqualification recommendations for competitive athletes with cardiovascular abnormalities: task force 3: hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and other cardiomyopathies, and myocarditis: a scientific statement from the American Heart Association and American College of Cardiology.
      ). And although studies have shown that athletes with ICDs can safely exercise
      • Lampert R.
      • Olshansky B.
      • Heidbuchel H.
      • et al.
      Safety of sports for athletes with implantable cardioverter-defibrillators: results of a prospective, multinational registry.
      ,
      • Saarel E.V.
      • Law I.
      • Berul C.I.
      • et al.
      Safety of sports for young patients with implantable cardioverter-defibrillators: long-term results of the multinational ICD sports registry.
      and recent guidelines have started to loosen this restriction — albeit minimally
      • Zipes D.P.
      • Link M.S.
      • Ackerman M.J.
      • Kovacs R.J.
      • Myerburg R.J.
      • Estes 3rd, N.A.
      Eligibility and disqualification recommendations for competitive athletes with cardiovascular abnormalities: task force 9: arrhythmias and conduction defects: a scientific statement from the American Heart Association and American College of Cardiology.
      ,
      • Maron B.J.
      • Udelson J.E.
      • Bonow R.O.
      • et al.
      Eligibility and disqualification recommendations for competitive athletes with cardiovascular abnormalities: task force 3: hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and other cardiomyopathies, and myocarditis: a scientific statement from the American Heart Association and American College of Cardiology.
      ,
      • Pelliccia A.
      • Sharma S.
      • Gati S.
      • et al.
      2020 ESC guidelines on sports cardiology and exercise in patients with cardiovascular disease.
      — there remains a paucity of data on outcomes for athletes with GHD and an ICD who choose to RTP.
      Our analyses herein show that, although the risk of BCEs for such patients is not zero, the data support that competitive athletes with ICDs can safely participate in higher-intensity, competitive sports with minimal risk of damage to the device during sports, failed ICD rescue, or other adverse events. Although it is clear that athletes who receive an ICD are far more likely to experience at least one BCE during their RTP period than those GHD athletes who were not treated with an ICD, the main reason for this is that athletes who received a VT/VF-terminating therapy from their device were, in fact, appropriately risk-stratified and rightfully implanted with the device. This is supported by the fact that an equal number of patients received an ICD shock while engaged in sports compared with those received a shock outside of sports. This can also be observed by looking at the severity of the phenotype in patients who received an ICD.
      For example, in this cohort of patients, the athletes with LQTS and an ICD had a significantly longer QTc than the LQTS athletes without a device (496±48 ms vs 460±30 ms; P<.0001). All of this not only shows safety of playing sports with an ICD but shows the role (and effect) of accurate risk stratification and patient-specific tailoring of treatment recommendations before ICD placement. This further underscores that, before successful SDM (that concludes with an RTP) can occur, the athlete must have been well evaluated, well risk-stratified, and well treated. In short, when evaluated at the Mayo Clinic Windland Smith Rice Genetic Heart Rhythm Clinic, patients follow a comprehensive RTP protocol
      • Tobert K.E.
      • Bos J.M.
      • Garmany R.
      • Ackerman M.J.
      Return-to-play for athletes with long QT syndrome or genetic heart diseases predisposing to sudden death.
      • Johnson J.N.
      • Ackerman M.J.
      Competitive sports participation in athletes with congenital long QT syndrome.
      • Johnson J.N.
      • Ackerman M.J.
      Return to play? Athletes with congenital long QT syndrome.
      which includes full clinical evaluation with two electrocardiograms obtained on consecutive days, an echocardiogram, 24-hour Holter monitoring, treadmill exercise stress test, genetic testing, and additional consults where needed (psychiatry, genetic counseling, etc) Next, patients (and parents/guardians where appropriate) are provided with the current guidelines and literature on sports participation in GHD, and the risks of continued sports participation (with an ICD) are discussed. If — following this SDM approach — RTP is desired, the following conditions must be met or followed to support a full return: the treatment plans should be strictly followed, coaches and school administrators must be informed, a personal automatic external defibrillator should be obtained, proper hydration and electrolyte replenishment should be maintained during and after exercise, QT-prolonging drugs are to be avoided (for those athletes with LQTS), and the athlete should undergo regular follow-up (typically 1-2 times per year) during which the risk profile and treatment plan should be re-evaluated.
      The notion of implanting an ICD for primary prevention in an athlete based on their athletic status has become a clinical possibility in recent years. Despite the relative low risk of complications and low prevalence of inappropriate shock seen in our patients, neither of these are trivial. Therefore, an athlete’s desire to continue participation in competitive sports should not be the only qualifying factor for installing an ICD. Instead, guideline-based, GHD-specific ICD indications should always be followed. It is important that as further data evolve from GHD specialty centers, physicians continue to progress their practice and follow observational data-driven treatment optimization, ensuring that there is a balance between true risk-stratification and prevention of over-implantation. This study continues to bolster the notion that athlete status does not mandate an ICD, and that other more effective treatment plans, that do not involve an ICD, could be beneficial and preferred for certain athletes with GHD. Akin with our non-athletes with the GHDs represented in this study, unless the athlete presented with resuscitated SCA, most athletes do not need and should not receive an ICD for treatment of their underlying GHD.
      Looking at outcomes for the specific GHDs included in our cohort, some interesting observations can be made. For example, although incidence of BCE for the overall cohort was higher in those with ICD, event rates for athletes with HCM and CPVT were nearly similar between athletes with ICDs and without ICDs (Figure 2). These data are consistent with the current management of these diseases
      • Ommen S.R.
      • Mital S.
      • Burke M.A.
      • et al.
      2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy: executive summary: a report of the American College of Cardiology/American Heart Association joint committee on clinical practice guidelines.
      ,
      • Al-Khatib S.M.
      • Stevenson W.G.
      • Ackerman M.J.
      • et al.
      2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: executive summary: a report of the American College of Cardiology/American Heart Association task force on clinical practice guidelines and the Heart Rhythm Society.
      and highlight the challenges of risk stratification and treatment options for these conditions.
      Currently, for HCM, risk stratification is predicated on the presence of clinical risk factors, but the strength of each to predict risk remains low.
      • Ommen S.R.
      • Mital S.
      • Burke M.A.
      • et al.
      2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy: executive summary: a report of the American College of Cardiology/American Heart Association joint committee on clinical practice guidelines.
      As such, the use of ICDs in HCM has become a popular modern intervention in SCD prevention.
      • Trivedi A.
      • Knight B.P.
      ICD therapy for primary prevention in hypertrophic cardiomyopathy.
      ,
      • Maron B.J.
      • Maron M.S.
      Hypertrophic cardiomyopathy.
      Further treatment optimization is necessary in HCM and novel therapeutics are a current area of study for this disease.
      • Olivotto I.
      • Oreziak A.
      • Barriales-Villa R.
      • et al.
      Mavacamten for treatment of symptomatic obstructive hypertrophic cardiomyopathy (EXPLORER-HCM): a randomised, double-blind, placebo-controlled, phase 3 trial.
      In patients with CPVT, the role of an ICD as part of the treatment plan remains part of ongoing debate and is mostly focused on the potential risk of ICD device itself perpetuating an arrhythmia rather than terminating it. Studies have shown that there is an increased burden of appropriate ICD therapies in patients with CPVT that do not terminate arrhythmias, and these shocks can actually be proarrhythmic, resulting in more malignant arrhythmic events or electrical storms in these patients.
      • Miyake C.Y.
      • Webster G.
      • Czosek R.J.
      • et al.
      Efficacy of implantable cardioverter defibrillators in young patients with catecholaminergic polymorphic ventricular tachycardia: success depends on substrate.
      ,
      • Roston T.M.
      • Vinocur J.M.
      • Maginot K.R.
      • et al.
      Catecholaminergic polymorphic ventricular tachycardia in children: analysis of therapeutic strategies and outcomes from an international multicenter registry.
      As such, left cardiac sympathetic denervation has emerged as a safe, minimally invasive alternative for SCD prevention in CPVT patients.
      • De Ferrari G.M.
      • Dusi V.
      • Spazzolini C.
      • et al.
      Clinical management of catecholaminergic polymorphic ventricular tachycardia: the role of left cardiac sympathetic denervation.
      Further, even among CPVT patients who presented with SCA while undiagnosed and untreated, no survival benefit has been shown among those who received an ICD compared with those treated with either beta blocker monotherapy, beta blocker and flecainide combination therapy, or triple therapy with the addition of left cardiac sympathetic denervation.
      • van der Werf C.
      • Kannankeril P.J.
      • Sacher F.
      • et al.
      Flecainide therapy reduces exercise-induced ventricular arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia.
      Accordingly, whether an athlete or not, the majority of patients with CPVT are now being managed without an ICD in most GHD specialty centers.
      One of the more challenging diagnoses in determining safety of RTP is ARVC. Previous studies have linked exercise to exacerbation of ARVC’s phenotypic expressivity,
      • James C.A.
      • Bhonsale A.
      • Tichnell C.
      • et al.
      Exercise increases age-related penetrance and arrhythmic risk in arrhythmogenic right ventricular dysplasia/cardiomyopathy-associated desmosomal mutation carriers.
      • Saberniak J.
      • Hasselberg N.E.
      • Borgquist R.
      • et al.
      Vigorous physical activity impairs myocardial function in patients with arrhythmogenic right ventricular cardiomyopathy and in mutation positive family members.
      • Ruwald A.C.
      • Marcus F.
      • Estes 3rd, N.A.
      • et al.
      Association of competitive and recreational sport participation with cardiac events in patients with arrhythmogenic right ventricular cardiomyopathy: results from the North American multidisciplinary study of arrhythmogenic right ventricular cardiomyopathy.
      which has generally led to strict enforcement of no activity guidelines.
      • Prior D.
      • La Gerche A.
      Exercise and arrhythmogenic right ventricular cardiomyopathy.
      In our small sample, we did observe a slightly higher rate of BCEs in ARVC athletes, but this was in a vastly underpowered cohort. Although current guidelines echo the class IA-sport–only recommendation, whether athletes with ARVC should enter an SDM process for RTP is subject to ongoing debate and will need comprehensive evaluation of a larger cohort of ARVC patients.
      To provide details on all patients seen in Mayo Clinic’s Windland Smith Rice Genetic Heart Rhythm Clinic with an ICD who chose to RTP, we included patients with IVF in the analyses. Although we recognize that this is a diagnosis by exclusion, these patients have undergone comprehensive diagnostic evaluation (including genetic testing) at our institution. Furthermore, over the past few years, many new VF/SCD-predisposing GHDs and endophenotypes have been identified among patients previously classified as IVF. As such, it is important to report the outcomes on these patients, and we show here that these IVF patients have favorable outcomes after adhering to the RTP protocol. Whereas two patients did experience three shocks each during athletics, the majority of IVF patients (13 of 15 [86.7%]) did not have an event during their RTP.
      Of course, some of the most important aspects of an athlete’s RTP are physical and psychological well-being. Exercise, in any population of patients, is essential in maintaining health, both physical and mental, and preventing obesity and further cardiovascular disease.
      • Kim B.Y.
      • Choi D.H.
      • Jung C.H.
      • Kang S.K.
      • Mok J.O.
      • Kim C.H.
      Obesity and physical activity.
      In fact, adolescent athletes report higher survey scores in physical functioning, general health, social functioning, and mental health than their nonathletic peers.
      • Snyder A.R.
      • Martinez J.C.
      • Bay R.C.
      • Parsons J.T.
      • Sauers E.L.
      • Valovich McLeod T.C.
      Health-related quality of life differs between adolescent athletes and adolescent nonathletes.
      In contrast, athletes who are disqualified from competitive sports following a cardiac disease diagnosis are clearly affected psychologically and progress through the four stages of psychological impact: 1) immediate reaction, 2) coping and grief, 3) adaptation, and 4) acceptance.
      • Asif I.M.
      • Price D.
      • Fisher L.A.
      • et al.
      Stages of psychological impact after diagnosis with serious or potentially lethal cardiac disease in young competitive athletes: a new model.
      A physician’s understanding of this psychological distress mechanism is paramount when evaluating these patients, and additional support and reassurance should be offered when risk stratifying, treating, and potentially enabling RTP in these athletes.

      Study Limitations

      This retrospective study from a tertiary specialty center does not come without limitations. The majority of patients evaluated in Mayo Clinic’s Windland Smith Rice Genetic Heart Rhythm Clinic are referred to the clinic seeking comprehensive risk stratification and treatment optimization by a single genetic cardiologist (MJA). This referral-based dataset then comes with the expected referral bias but is also responsible for some patients only coming to the specialty clinic for a single evaluation with follow-up taking place with the patient’s primary cardiologist. Although these patients and physicians do communicate frequently with our clinic, a small number of BCEs might have occurred during follow-up without our clinic being made aware of them resulting in an underestimate of their true event rate.
      On the other hand, all patients evaluated in the Mayo Clinic Windland Smith Rice Genetic Heart Rhythm Clinic are encouraged to follow-up annually or biennially. However, it is possible that patients who experience recurring BCEs return for follow-up or remain in contact with our clinic more regularly than those who remain BCE-free. Consequently, this could lead instead to a slight overestimation of the BCE rates in this retrospective analysis of this cohort. Some of the disease subgroups in this cohort, such as ARVC, are underpowered to identify statistically significant differences and derive clinical conclusions from the incidence rates.

      Conclusion

      Although the risk of BCEs during the RTP period for athletes with ICDs is not zero, the ICD properly terminated all arrhythmic events and GHD-related mortality remains zero. Further, the data in this study show that, although device-related complications do occur, they were not caused by sports-related activities. Shared decision making should set the foundation for these athletes returning to play, ensuring the athlete is properly risk-stratified and treated for their GHD by a qualified health care provider. After being properly risk-stratified and treated, SDM culminating in the GHD athlete’s successful and safe RTP is feasible even with an ICD. Accordingly, an athlete with GHD and an ICD should no longer be viewed as an oxymoron but a mutually possible coexistence. Consequently, the onus should shift away from the athlete and his/her GHD to the health care provider caring for that athlete with appropriate self-reflection occurring to answer the pertinent question: “Am I the appropriate health care provider to be navigating this SDM journey?” So, rather than “if in doubt, kick them out,” the evolved approach should be “if in doubt, refer them out.”

      Potential Competing Interests

      Dr Ackerman is a consultant for Abbott, ARMGO Pharma, Boston Scientific, Bristol Myers Squibb, Daiichi Sankyo, Invitae, LQT Therapeutics, Medtronic, and UpToDate; and with Mayo Clinic has an equity/royalty relationship with AliveCor, Anumana, and Pfizer. The remaining authors report no potential competing interests.

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