title: Implications of new-onset atrial fibrillation after cardiac surgery on long-term prognosis: a community-based study.
abstract: BACKGROUND
  Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery. Data are lacking on the long-term prognostic implications of POAF. We hypothesized that POAF, which reflects underlying cardiovascular pathophysiologic substrate, is a predictive marker of late AF and long-term mortality.
  
  
  METHODS
  We identified 603 Olmsted County, Minnesota, residents without prior documented history of AF who underwent coronary artery bypass graft and/or valve surgery from 2000 to 2005. Patients were monitored for first documentation of late AF or death at >30 days postoperatively. Multivariate Cox regression models were used to assess the independent association of POAF with late AF and long-term mortality.
  
  
  RESULTS
  After a mean follow-up of 8.3 ± 4.2 years, freedom from late AF was less with POAF than no POAF (57.4% vs 88.9%, P < .001). The risk of late AF was highest within the first year at 18%. Univariate analysis demonstrated that POAF was associated with significantly increased risk of late AF [hazard ratio (HR), 5.09; 95% CI, 3.65-7.22] and long-term mortality (HR, 1.79; 95% CI, 1.38-2.22). After adjustment for age, sex, and clinical and surgical risk factors, POAF remained independently associated with development of late AF (HR, 3.52; 95% CI, 2.42-5.13) but not long-term mortality (HR, 1.16; 95% CI, 0.87-1.55). Conversely, late AF was independently predictive of long-term mortality (HR, 3.25; 95% CI, 2.42-4.35). Diastolic dysfunction independently influenced the risk of late AF and long-term mortality.
  
  
  CONCLUSIONS
  Postoperative atrial fibrillation was an independent predictive marker of late AF, whereas late AF, but not POAF, was independently associated with long-term mortality. Patients who develop new-onset POAF should be considered for continuous anticoagulation at least during the first year following cardiac surgery.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN. Electronic address: melduni.rowlens@mayo.edu.
authors.forename: Rowlens M
authors.initials: RM
authors.lastname: Melduni
authors.affiliation: Division of Cardiovascular Surgery, Mayo Clinic, Rochester, MN.
authors.forename: Hartzell V
authors.initials: HV
authors.lastname: Schaff
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, MN.
authors.forename: Kent R
authors.initials: KR
authors.lastname: Bailey
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, MN.
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Cha
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: Naser M
authors.initials: NM
authors.lastname: Ammash
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: James B
authors.initials: JB
authors.lastname: Seward
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Gersh
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000209:etiology; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D011159:Population Surveillance; D011183:Postoperative Complications; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors