title: Preoperative atrial fibrillation increases risk of thromboembolic events after left ventricular assist device implantation.
abstract: BACKGROUND
  Because no series has specifically analyzed the impact of preoperative atrial fibrillation (AF) on patients already at higher risk of thromboembolism after implantation of a left ventricular assist device (LVAD), we review our experience with these patients.
  
  
  METHODS
  Between July 2003 and September 2011, 389 patients (308 male) underwent implantation of a continuous flow LVAD at University of Michigan Hospital and Mayo Clinic. Median age at implant was 60 years (range, 18 to 79 years). Preoperative AF was present in 120 patients (31%). Outcomes were analyzed for the association of preoperative AF and postoperative thromboembolic (TE) events defined as stroke, transient ischemic attack, hemolysis, or pump thrombosis. Thromboembolic events occurring within the first 30 days were not counted.
  
  
  RESULTS
  One hundred thirty-eight TEs events occurred in 97/389 patients (25%) for an event rate of 0.31 TE events/patient-years of support. Freedom from a TE event in patients with preoperative AF was 62% at 1 year and 46% at 2 years compared with 79% and 72% at 1 and 2 years, respectively, in patients without preoperative AF (p < 0.001). Median survival was 10 months (maximum 7.2 years, total 439 patient-years). Preoperative AF did not decrease late survival at 1 and 2 years after LVAD implant (preop AF: 85% and 70% versus no preop AF: 82% and 70%, respectively; p = 0.55).
  
  
  CONCLUSIONS
  Patients with preoperative AF have a lower freedom from TE events after LVAD implant. While overall late survival was not significantly reduced in these patients, refinement in anticoagulation strategies after VAD implant may be required.
authors.affiliation: Division of Cardiovascular Surgery, Department of General Surgery, Mayo Clinic College of Medicine, Rochester, Minnesota. Electronic address: stulak.john@mayo.edu.
authors.forename: John M
authors.initials: JM
authors.lastname: Stulak
authors.forename: Salil
authors.initials: S
authors.lastname: Deo
authors.forename: John
authors.initials: J
authors.lastname: Schirger
authors.forename: Keith D
authors.initials: KD
authors.lastname: Aaronson
authors.forename: Soon J
authors.initials: SJ
authors.lastname: Park
authors.forename: Lyle D
authors.initials: LD
authors.lastname: Joyce
authors.forename: Richard C
authors.initials: RC
authors.lastname: Daly
authors.forename: Francis D
authors.initials: FD
authors.lastname: Pagani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000150:complications / Q000628:therapy*; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D057234:Preoperative Period; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013923:Thromboembolism / Q000453:epidemiology / Q000209:etiology*; D055815:Young Adult
keywords: 24; 27; AF; CI; GI; HR; INR; LVAD; TE; TIA; VAD; atrial fibrillation; confidence interval; gastrointestinal; hazard ratio; international normalized ratio; left ventricular assist device; preop; preoperative; thromboembolic; transient ischemic attack; ventricular assist device