title: Burden, timing, and relationship of cardiovascular hospitalization to mortality among Medicare beneficiaries with newly diagnosed atrial fibrillation.
abstract: BACKGROUND
  Limited data exist on the burden and relationship of cardiovascular (CV) hospitalization to mortality after newly diagnosed with atrial fibrillation (AF).
  
  
  METHODS
  Using a 20% sample of nationwide Medicare Part A and B claims data, we performed a retrospective cohort study of Medicare beneficiaries with newly diagnosed AF (2004-2008). Cox proportional hazards time-varying exposures were used to determine the risk of death among patients with CV hospitalization after AF diagnosis.
  
  
  RESULTS
  Of 228,295 patients (mean age 79.6 ± 7.4 years, 56% female), 57% had a CV hospitalization after diagnosis of AF (41% in the first year). The most common primary CV hospitalization diagnoses were AF/supraventricular arrhythmias (21%), heart failure (19%), myocardial infarction (11%), and stroke/transient ischemic attack (7.7%). Incidence rates per 1,000 person-years among patients with and without CV hospitalization were 114 and 87, respectively, for all-cause mortality. After adjustment for covariates and time to CV hospitalization, the hazard of mortality among newly diagnosed AF patients with CV hospitalization, compared with those without CV hospitalization, was higher (hazard ratio 1.22, 95% CI 1.20-1.24).
  
  
  CONCLUSIONS
  Cardiovascular hospitalization is common in the first year after AF diagnosis. Atrial fibrillation, heart failure, myocardial infarction, and stroke/transient ischemic attack account for half of primary hospitalization diagnosis. Cardiovascular hospitalization is independently associated with mortality, irrespective of time from diagnosis to first hospitalization, and represents a critical inflection point in survival trajectory. These findings highlight the importance of CV hospitalization as a marker of disease progression and poor outcomes. Efforts to clarify the determinants of hospitalization could inform interventions to reduce admissions and improve survival.
authors.affiliation: Stanford University School of Medicine, Stanford, CA. Electronic address: mintu@stanford.edu.
authors.forename: Mintu P
authors.initials: MP
authors.lastname: Turakhia
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Solomon
authors.forename: Mehul
authors.initials: M
authors.lastname: Jhaveri
authors.forename: Pamela
authors.initials: P
authors.lastname: Davis
authors.forename: Michael R
authors.initials: MR
authors.lastname: Eber
authors.forename: Ryan
authors.initials: R
authors.lastname: Conrad
authors.forename: Nicholas
authors.initials: N
authors.lastname: Summers
authors.forename: Darius
authors.initials: D
authors.lastname: Lakdawalla
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000191:economics / Q000401:mortality*; D015331:Cohort Studies; D017281:Cost of Illness; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D014481:United States