title: Myocardial infarction is a frequent cause of exercise-related resuscitated out-of-hospital cardiac arrest in a general non-athletic population.
abstract: BACKGROUND
  Performing exercise is shown to prevent cardiovascular disease, but the risk of an out-of-hospital cardiac arrest (OHCA) is temporarily increased during strenuous activity. We examined the etiology and outcome after successfully resuscitated OHCA during exercise in a general non-athletic population.
  
  
  METHODS
  Consecutive patients with OHCA were admitted with return of spontaneous circulation (ROSC) or on-going resuscitation at hospital arrival (2002-2011). Patient charts were reviewed for post-resuscitation data. Exercise was defined as moderate/vigorous physical activity.
  
  
  RESULTS
  A total of 1393 OHCA-patients were included with 91(7%) arrests occurring during exercise. Exercise-related OHCA-patients were younger (60 ± 13 vs. 65 ± 15, p<0.001) and predominantly male (96% vs. 69%, p<0.001). The arrest was more frequently witnessed (94% vs. 86%, p=0.02), bystander CPR was more often performed (88% vs. 54%, p<0.001), time to ROSC was shorter (12 min (IQR: 5-19) vs. 15 (9-22), p=0.007) and the primary rhythm was more frequently shock-able (91% vs. 49%, p<0.001) compared to non-exercise patients. Cardiac etiology was the predominant cause of OHCA in both exercise and non-exercise patients (97% vs. 80%, p<0.001) and acute coronary syndrome was more frequent among exercise patients (59% vs. 38%, p<0.001). One-year mortality was 25% vs. 65% (p<0.001), and exercise was even after adjustment associated with a significantly lower mortality (HR=0.40 (95%CI: 0.23-0.72), p=0.002).
  
  
  CONCLUSIONS
  OHCA occurring during exercise was associated with a significantly lower mortality in successfully resuscitated patients even after adjusting for confounding factors. Acute coronary syndrome was more common among exercise-related cardiac arrest patients.
authors.affiliation: Department of Cardiology 2142, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Denmark. Electronic address: helle.soholm@gmail.com.
authors.forename: Helle
authors.initials: H
authors.lastname: Søholm
authors.affiliation: Department of Cardiology 2142, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Kjaergaard
authors.affiliation: Department of Cardiology 2142, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Denmark.
authors.forename: Jakob Hartvig
authors.initials: JH
authors.lastname: Thomsen
authors.affiliation: Department of Cardiology 2142, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Denmark.
authors.forename: John
authors.initials: J
authors.lastname: Bro-Jeppesen
authors.affiliation: Emergency Medical Services, Copenhagen, The Capital Region of Denmark, Denmark.
authors.forename: Freddy K
authors.initials: FK
authors.lastname: Lippert
authors.affiliation: Department of Cardiology 2142, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
authors.affiliation: Department of Cardiothoracic Anesthesia 4142, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Denmark.
authors.forename: Michael
authors.initials: M
authors.lastname: Wanscher
authors.affiliation: Department of Cardiology 2142, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Hassager
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004632:Emergency Medical Services / Q000379:methods / Q000706:statistics & numerical data; D015444:Exercise / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000175:diagnosis; D058687:Out-of-Hospital Cardiac Arrest / Q000453:epidemiology / Q000209:etiology* / Q000628:therapy*; D005082:Physical Exertion / Q000502:physiology*; D016016:Proportional Hazards Models; D011998:Recreation / Q000502:physiology; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D018709:Statistics, Nonparametric; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome
keywords: Cardiac arrest; Cardiopulmonary resuscitation; Exercise; Heart; Myocardial infarction