title: Readmissions after implantation of axial flow left ventricular assist device.
abstract: OBJECTIVE
  The purpose of this study was to determine the occurrence and causes of readmissions after implantation of axial flow left ventricular assist device (LVAD).
  
  
  BACKGROUND
  Based on the REMATCH (Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure) study experience, readmissions after LVAD implantation are thought to be frequent.
  
  
  METHODS
  We retrospectively analyzed admissions to our facility in a cohort of 115 patients implanted between January 2008 and July 2011 with the HeartMate II axial flow LVAD, of whom 42 were bridged to transplant. To account for repeated events, Andersen-Gill models were used to determine possible predictors.
  
  
  RESULTS
  The patients were followed for 1.4 ± 0.9 years. There were 224 readmissions in 83 patients. The overall readmission rate was 1.64 ± 1.97 per patient-year of follow-up. The readmission rate for the first 6 months was 2.0 ± 2.3 and decreased to 1.2 ± 2.1 during subsequent follow-up. Leading causes were bleeding (66 readmissions in 34 patients), mostly gastrointestinal bleed (51 in 27 patients), cardiac (51 in 36 patients, most for HF or arrhythmia), infections (32 in 25 patients) of which 6 were pump related, and thrombosis (20 in 15 patients) including 13 readmissions due to hemolysis. Preoperative variables associated with (fewer) readmissions in a multivariate model include residence within our hospital-extended referral zone of Minnesota and the neighboring states (hazard ratio: 0.66; 95% confidence interval: 0.48 to 0.91; p = 0.011), hemoglobin (hazard ratio: 0.91, 95% confidence interval: 0.84 to 0.99; p = 0.027) and N-terminal pro-B-type natriuretic peptide (hazard ratio: 0.98; 95% confidence interval: 0.96 to 1.0 per 1,000-unit increase, p = 0.022). C-statistic for the model: 0.63.
  
  
  CONCLUSIONS
  Readmission rates after axial flow LVAD implantation decrease during the first 6 months and then stabilize. The leading causes are bleeding, cardiac (heart failure and arrhythmia), infections, and thrombosis.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Tal
authors.initials: T
authors.lastname: Hasin
authors.forename: Yariv
authors.initials: Y
authors.lastname: Marmor
authors.forename: Walter
authors.initials: W
authors.lastname: Kremers
authors.forename: Yan
authors.initials: Y
authors.lastname: Topilsky
authors.forename: Cathy J
authors.initials: CJ
authors.lastname: Severson
authors.forename: John A
authors.initials: JA
authors.lastname: Schirger
authors.forename: Barry A
authors.initials: BA
authors.lastname: Boilson
authors.forename: Alfredo L
authors.initials: AL
authors.lastname: Clavell
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Rodeheffer
authors.forename: Robert P
authors.initials: RP
authors.lastname: Frantz
authors.forename: Brooks S
authors.initials: BS
authors.lastname: Edwards
authors.forename: Naveen L
authors.initials: NL
authors.lastname: Pereira
authors.forename: John M
authors.initials: JM
authors.lastname: Stulak
authors.forename: Lyle
authors.initials: L
authors.lastname: Joyce
authors.forename: Richard
authors.initials: R
authors.lastname: Daly
authors.forename: Soon J
authors.initials: SJ
authors.lastname: Park
authors.forename: Sudhir S
authors.initials: SS
authors.lastname: Kushwaha
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006331:Heart Diseases / Q000209:etiology; D006333:Heart Failure / Q000601:surgery*; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D010359:Patient Readmission / Q000706:statistics & numerical data* / Q000639:trends; D016459:Prosthesis-Related Infections / Q000209:etiology; D012189:Retrospective Studies