title: Distinctive profile of sudden cardiac arrest in middle-aged vs. older adults: a community-based study.
abstract: BACKGROUND
  While sudden cardiac arrest (SCA) rates increase with age, middle-aged adults (35-59 years) may comprise a significant proportion of SCA cases in the community (30-40%). However, there is a lack of studies evaluating SCA risk factors specifically associated with this age-group of the population.
  
  
  METHODS
  Using prospective multiple-source surveillance methodology we identified cases of SCA ≥35 years in the ongoing Oregon Sudden Unexpected Death Study (Portland, Oregon metropolitan area, population≈1,000,000). Out-of-hospital SCA cases, aged 35-59 years were compared to older SCA cases (≥60 years) in a comprehensive analysis of clinical profile of SCA.
  
  
  RESULTS
  The middle-aged (n=753) compared to older (n=1251) cases were more likely to be male, obese, have sleep apnea and seizure disorder (all p≤0.001); and were less likely to have a history of hypertension, diabetes mellitus, known coronary artery disease, congestive heart failure and syncope (all p<0.01). In multivariable analyses the middle-aged group had higher likelihood of male sex (O.R. 1.67, 95% C.I. 1.29-2.18), obesity (2.20, 1.52-3.19), sleep apnea (2.30, 1.44-3.68) and seizure disorder (2.69, 1.64-4.42); and lower rates of known coronary artery disease (0.57, 0.43-0.74) and congestive heart failure (0.35, 0.25-0.48).
  
  
  CONCLUSIONS
  SCA in the middle-aged adult was distinguishable from older subjects by higher rates of obesity, sleep apnea and seizure disorder; and lower prevalence of traditional clinical risk markers. With the growing epidemic of obesity, these findings have implications for SCA burden; and suggest the need for a clinical and investigational focus on SCA prediction and prevention in the middle-aged adult, that is distinct from older adults.
authors.affiliation: The Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States.
authors.forename: Amit
authors.initials: A
authors.lastname: Noheria
authors.forename: Carmen
authors.initials: C
authors.lastname: Teodorescu
authors.forename: Audrey
authors.initials: A
authors.lastname: Uy-Evanado
authors.forename: Kyndaron
authors.initials: K
authors.lastname: Reinier
authors.forename: Ronald
authors.initials: R
authors.lastname: Mariani
authors.forename: Karen
authors.initials: K
authors.lastname: Gunson
authors.forename: Jonathan
authors.initials: J
authors.lastname: Jui
authors.forename: Sumeet S
authors.initials: SS
authors.lastname: Chugh
mesh_terms: D000328:Adult; D000368:Aged; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D005260:Female; D006323:Heart Arrest / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods; D011446:Prospective Studies; D012111:Residence Characteristics
keywords: Community; Coronary artery disease; Middle-age; Obesity; Sudden-death