title: Readmissions after cardiac surgery: experience of the National Institutes of Health/Canadian Institutes of Health research cardiothoracic surgical trials network.
abstract: BACKGROUND
  Readmissions are a common problem in cardiac surgery. The goal of this study was to examine the frequency, timing, and associated risk factors for readmission after cardiac operations.
  
  
  METHODS
  A 10-center cohort study prospectively enrolled 5,158 adult cardiac surgical patients (5,059 included in analysis) to assess risk factors for infection after cardiac operations. Data were also collected on all-cause readmissions occurring within 65 days after the operation. Major outcomes included the readmission rate stratified by procedure type, cause of readmission, length of readmission stay, and discharge disposition after readmission. Multivariable Cox regression was used to determine risk factors for time to first readmission.
  
  
  RESULTS
  The overall rate of readmission was 18.7% (number of readmissions, 945). When stratified by the most common procedure type, readmission rates were isolated coronary artery bypass grafting, 14.9% (n = 248); isolated valve, 18.3% (n = 337); and coronary artery bypass grafting plus valve, 25.0% (n = 169). The three most common causes of first readmission within 30 days were infection (17.1% [n = 115]), arrhythmia (17.1% [n = 115]), and volume overload (13.5% [n = 91]). More first readmissions occurred within 30 days (80.6% [n = 672]) than after 30 days (19.4% [n = 162]), and 50% of patients were readmitted within 22 days from the index operation. The median length of stay during the first readmission was 5 days. Discharge in 15.8% of readmitted patients (n = 128) was to a location other than home. Baseline patient characteristics associated with readmission included female gender, diabetes mellitus on medication, chronic obstructive pulmonary disease, elevated creatinine, lower hemoglobin, and longer operation time. More complex surgical procedures were associated with an increased risk of readmission compared with the coronary artery bypass grafting group.
  
  
  CONCLUSIONS
  Nearly 1 of 5 patients who undergo cardiac operations require readmission, an outcome with significant health and economic implications. Management practices to avert in-hospital infections, reduce postoperative arrhythmias, and avoid volume overload offer important targets for quality improvement.
authors.affiliation: Division of Cardiovascular and Thoracic Surgery, Duke University Medical Center, Durham, North Carolina.
authors.forename: Alexander
authors.initials: A
authors.lastname: Iribarne
authors.affiliation: International Center for Health Outcomes and Innovation Research (InCHOIR), Department of Health Evidence and Policy, Icahn School of Medicine at Mount Sinai, New York, New York. Electronic address: helena.l.chang@mountsinai.org.
authors.forename: Helena
authors.initials: H
authors.lastname: Chang
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: John H
authors.initials: JH
authors.lastname: Alexander
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Cleveland Clinic, Cleveland, Ohio.
authors.forename: A Marc
authors.initials: AM
authors.lastname: Gillinov
authors.affiliation: International Center for Health Outcomes and Innovation Research (InCHOIR), Department of Health Evidence and Policy, Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Ellen
authors.initials: E
authors.lastname: Moquete
authors.affiliation: Department of Cardiothoracic Surgery, Icahn School of Medicine at Mount Sinai, Mount Sinai Beth Israel, New York, New York.
authors.forename: John D
authors.initials: JD
authors.lastname: Puskas
authors.affiliation: International Center for Health Outcomes and Innovation Research (InCHOIR), Department of Health Evidence and Policy, Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Emilia
authors.initials: E
authors.lastname: Bagiella
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Acker
authors.affiliation: Division of Cardiothoracic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: Mayer
authors.affiliation: Department of Cardiovascular Sciences, East Carolina Heart Institute at East Carolina University, Greenville, North Carolina.
authors.forename: T Bruce
authors.initials: TB
authors.lastname: Ferguson
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Department of Surgery, University of Virginia Health System, Charlottesville, Virginia.
authors.forename: Sandra
authors.initials: S
authors.lastname: Burks
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, Montreal Heart Institute, University of Montreal, Montreal, Quebec, Canada.
authors.forename: Louis P
authors.initials: LP
authors.lastname: Perrault
authors.affiliation: Division of Cardiovascular and Thoracic Surgery, Duke University Medical Center, Durham, North Carolina.
authors.forename: Stacey
authors.initials: S
authors.lastname: Welsh
authors.affiliation: Department of Neurology, University of Virginia Health System, Charlottesville, Virginia.
authors.forename: Karen C
authors.initials: KC
authors.lastname: Johnston
authors.affiliation: National Institutes of Health Heart Center at Suburban Hospital, Bethesda, Maryland.
authors.forename: Mandy
authors.initials: M
authors.lastname: Murphy
authors.affiliation: Department of Cardiovascular and Thoracic Surgery, Montefiore-Einstein Heart Center, New York, New York.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: DeRose
authors.affiliation: Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Alexis
authors.initials: A
authors.lastname: Neill
authors.affiliation: International Center for Health Outcomes and Innovation Research (InCHOIR), Department of Health Evidence and Policy, Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Edlira
authors.initials: E
authors.lastname: Dobrev
authors.affiliation: Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Kim T
authors.initials: KT
authors.lastname: Baio
authors.affiliation: Division of Cardiovascular Sciences, National Heart, Lung and Blood Institute, Bethesda, Maryland.
authors.forename: Wendy
authors.initials: W
authors.lastname: Taddei-Peters
authors.affiliation: International Center for Health Outcomes and Innovation Research (InCHOIR), Department of Health Evidence and Policy, Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Moskowitz
authors.affiliation: Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Patrick T
authors.initials: PT
authors.lastname: O'Gara
mesh_terms: D000328:Adult; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010359:Patient Readmission / Q000706:statistics & numerical data*; D011446:Prospective Studies; D013997:Time Factors