title: Outcomes associated with comorbid atrial fibrillation and heart failure in Medicare beneficiaries with acute coronary syndrome.
abstract: BACKGROUND
  Atrial fibrillation (AF) and heart failure (HF) are both common comorbid conditions of elderly patients with acute coronary syndrome (ACS), but published data on their associated clinical and economic outcomes are limited.
  
  
  METHODS
  Our study included patients from the Medicare Current Beneficiary Survey with an incident hospitalization for ACS between 03/01/2002 and 12/31/2006. Applying population weights, we identified 795 incident ACS patients, representing more than 2.5 million Medicare beneficiaries. Of this population, 13.1% had comorbid AF, and 22.9% had HF, which were identified from Medicare claims during the 6 months prior to the first ACS event (index date) Subsequent cardiovascular (CV) hospitalizations and mortality were compared using Kaplan-Meier curves. Cox proportional hazards regressions were used to estimate the relative risk of AF and HF on CV events and mortality. Healthcare costs were summarized for the calendar year in which the incident ACS event occurred.
  
  
  RESULTS
  HF was associated with a 41% higher risk of mortality (HR = 1.41; 95% confidence interval [CI] 1.05-1.89). Both AF (HR = 1.46; 95% CI 1.14-1.87) and HF (HR = 1.61; 95% CI 1.26-2.06) were associated with higher risks of subsequent CV events. During the year of the incident ACS event, ACS patients with comorbid AF or HF had approximately $18,000 higher total healthcare costs than those without these comorbidities.
  
  
  CONCLUSIONS
  Using a nationally representative sample of Medicare beneficiaries, we observed a significantly higher clinical and economic burden of patients hospitalized for ACS with comorbid AF and HF compared with those without these conditions.
authors.affiliation: Evidera, 430 Bedford Street Suite 300, Lexington, MA 02420, USA. Shih-Yin.Chen@evidera.com.
authors.forename: Shih-Yin
authors.initials: SY
authors.lastname: Chen
authors.forename: Concetta
authors.initials: C
authors.lastname: Crivera
authors.forename: Michael
authors.initials: M
authors.lastname: Stokes
authors.forename: Luke
authors.initials: L
authors.lastname: Boulanger
authors.forename: Jeff
authors.initials: J
authors.lastname: Schein
mesh_terms: D054058:Acute Coronary Syndrome / Q000191:economics / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D000368:Aged; D001281:Atrial Fibrillation / Q000191:economics / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D015897:Comorbidity; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data; D006333:Heart Failure / Q000191:economics / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data*; D063868:Patient Outcome Assessment; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012306:Risk; D012959:Socioeconomic Factors; D014481:United States / Q000453:epidemiology