title: Impact of age on long-term survival and quality of life following out-of-hospital cardiac arrest.
abstract: OBJECTIVE
  Early defibrillation programs have improved long-term outcomes following out-of-hospital cardiac arrest from ventricular fibrillation. Although long-term collective quality of life and survival are favorable, there are subsets of these patients who may be predisposed to worse outcomes. In particular, elderly patients may present with more comorbid medical conditions affecting their outcome. However, the impact of age on mortality rate and quality of life after rapid defibrillation is unknown.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  Hospital.
  
  
  METHODS
  All patients with an out-of-hospital cardiac arrest between November 1990 and January 2001 who received rapid defibrillation for ventricular fibrillation in Olmsted County, Minnesota. All patients received treatment at one hospital.
  
  
  METHODS
  Long-term outcome and quality of life were followed. Survival was estimated using the Kaplan-Meier method. The quality of life was established by an SF-36 survey.
  
  
  RESULTS
  Two hundred patients presented in ventricular fibrillation out-of-hospital cardiac arrest; of these, 138 (69%) survived to hospital admission, seven (4%) died in the emergency department, and 79 (39%) were discharged neurologically intact. The average age was 62+/-16 yrs, with 51% (n = 40) of the population > or =65. The average length of follow-up was 4.8+/-3.0 yrs. The 5-yr survival in patients <65 was 94% (confidence interval, 86-100%) and 66% (confidence interval, 52-84%) in patients > or =65 (p <.001). The observed survival in the younger group was not different from that expected in a U.S. age- and gender-matched population. However, in the older group, the expected survival was significantly lower compared with an age- and gender-matched U.S. population (p =.01) but similar to an age-, gender-, and disease-matched cohort of patients from Olmsted County not experiencing an arrest. In both age-dependent cohort populations, the quality of life scores crossed the norm in all categories with exception of vitality in patients >65 yrs old (42.6+/-7.2). In direct comparison between the two patient groups, the older cohort reported lower levels of physical functioning (p =.002), role-emotional score (p =.03), and role-physical score (p =.007). Other SF-36 scores were not different between the groups. Sixty-five percent of patients <65 yrs returned to work compared with 56% of older patients.
  
  
  CONCLUSIONS
  The survival rate for ventricular fibrillation out-of-hospital cardiac arrest is significantly improved by the presence of a rapid defibrillation program. In patients <65 yrs old, long-term survival is equal to that of normal individuals and quality of life is similar to the general population. The survival, although high, in older patients is less than that in age-matched healthy controls, and physical and emotional quality of life scores are decreased.
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: T Jared
authors.initials: TJ
authors.lastname: Bunch
authors.forename: Roger D
authors.initials: RD
authors.lastname: White
authors.forename: Akbar H
authors.initials: AH
authors.lastname: Khan
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Packer
mesh_terms: D000046:Academic Medical Centers / Q000706:statistics & numerical data; D000367:Age Factors; D000368:Aged; D015331:Cohort Studies; D003422:Critical Care; D004554:Electric Countershock; D004632:Emergency Medical Services; D005260:Female; D005500:Follow-Up Studies; D006323:Heart Arrest / Q000401:mortality* / Q000628:therapy; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D010351:Patient Discharge / Q000706:statistics & numerical data; D011788:Quality of Life; D012016:Reference Values; D012307:Risk Factors; D016019:Survival Analysis; D014693:Ventricular Fibrillation / Q000401:mortality* / Q000628:therapy