title: Atrial fibrillation significantly increases total mortality and stroke risk beyond that conveyed by the CHADS2 risk factors.
abstract: BACKGROUND
  Atrial fibrillation (AF) is associated with an increased risk of mortality and stroke. However, it is unclear if AF is independently associated with these poor outcomes or it is merely a risk marker of other processes that convey the risk.
  
  
  METHODS
  Consecutive patients who underwent angiography for suspicion of coronary artery disease, but without a history of AF, were studied. Traditional CHADS2 (congestive heart failure, hypertension, age >75 years, diabetes, stroke/transient ischemic attack) risk factors for each patient were recorded.
  
  
  RESULTS
  A total of 343 AF patients (age = 69 +/- 10 years, 215 [63%] male) and 2,945 non-AF patients (age = 63 +/- 12 years, 2,012 [67%] male) were studied. Among AF patients, 51 (15%) had a myocardial infarction (MI), 35 (10%) had a stroke, and 180 (52%) died. CHADS2 score incrementally increased risk of stroke (adjusted hazard ratio [HR] for 1:1.92, 2:2.30, 3:1.14, 4:3.83, 5:10.96; P-trend = 0.14), death (HR for 1:1.83, 2:2.34, 3:3.69, 4:2.27, 5:4.53; P-trend < 0.001), and major adverse cardiac event (MACE)(HR for 1:1.29, 2:1.54, 3:2.07, 4:2.41, 5:2.68; P-trend = 0.002). Among non-AF patients, CHADS2 score incrementally increased risk of stroke (HR for 1:1.18, 2:3.17, 3:5.08, 4:10.78, 5:7.50; P-trend < 0.001), MI (HR for 1:1.05, 2:1.46, 3:1.57, 4:0.53, 5:4.76; P-trend = 0.002), death (HR for 1:1.79, 2:3.22, 3:6.23, 4:9.09, 5:14.00; P-trend < 0.001), and MACE (HR for 1:1.47, 2:2.36, 3:4.16, 4:5.91, 5:7.56; P-trend < 0.001). Among all patients, both CHADS2 score (all P < or = 0.001) and AF were independent risk factors for stroke (AF: P = 0.002), MI (AF: P = 0.035), death (AF: P < 0.001), and MACE (AF: P < 0.001).
  
  
  CONCLUSIONS
  The CHADS2 score is a powerful predictor of stroke and death. AF increases the risk of these outcomes in an independent manner. These data support the concept that AF is a risk factor of future cardiovascular disease.
authors: Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors: Mark A
authors: MA
authors: Crandall
authors: Benjamin D
authors: BD
authors: Horne
authors: John D
authors: JD
authors: Day
authors: Jeffrey L
authors: JL
authors: Anderson
authors: Joseph B
authors: JB
authors: Muhlestein
authors: Brian G
authors: BG
authors: Crandall
authors: J Peter
authors: JP
authors: Weiss
authors: Jeffrey S
authors: JS
authors: Osborne
authors: Donald L
authors: DL
authors: Lappé
authors: T Jared
authors: TJ
authors: Bunch
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000401:mortality*; D015897:Comorbidity; D003324:Coronary Artery Disease / Q000401:mortality*; D005260:Female; D006333:Heart Failure / Q000401:mortality*; D006801:Humans; D006973:Hypertension / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000401:mortality*; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D020521:Stroke / Q000401:mortality*; D016019:Survival Analysis; D015996:Survival Rate; D014481:United States