title: Impact of Annual Hospital Volume on Outcomes after Left Ventricular Assist Device (LVAD) Implantation in the Contemporary Era.
abstract: BACKGROUND
  There are few data in the literature regarding impact of annual hospital volume on outcomes such as mortality and length of stay (LOS) post-LVAD implantation.
  
  
  METHODS
  We queried the nationwide inpatient sample from 2008 to 2011 using International Classification of Diseases, 9th Revision procedure code 37.66. We included patients ≥18 years without primary diagnosis of orthotopic heart transplant. Annual volume of LVAD implantation was computed for each hospital. Multivariable hierarchical mixed effect logistic regression models were used to determine predictors of in-hospital mortality and LOS.
  
  
  RESULTS
  There were 1749 LVAD implants from 2008 to 2011; patients had a mean age of 55.4 years, and 23% were female. In-hospital mortality decreased from 20.9% in the first tertile (1-22 LVADs/y) to 13.7% in the third tertile (≥35 LVADs/y) of hospital volume. Median LOS decreased from 34 days in the first tertile to 28 days in third tertile of hospital volume. The adjusted odds ratios of the highest tertile of hospital volume in predicting in-hospital mortality and LOS were 0.41 (0.26-0.64, P < .001) and 0.41 (0.23-0.73, P = .003), respectively. Restricted cubic spline analysis showed that a volume threshold of >20 LVADs/year was associated with favorable mortality rates of <10%.
  
  
  CONCLUSIONS
  High annual LVAD volume is associated with significantly decreased in-hospital mortality and LOS after LVAD implantation. Center experience is an important determinant of optimal patient outcomes.
authors.affiliation: Department of Cardiology, Lehigh Valley Health Network, Allentown, Pennsylvania. Electronic address: neerajshah86@gmail.com.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Shah
authors.affiliation: Department of Cardiology, Mount Sinai St. Luke's Roosevelt Hospital, New York, New York.
authors.forename: Ankit
authors.initials: A
authors.lastname: Chothani
authors.affiliation: Department of Cardiology, Staten Island University Hospital, New York, New York.
authors.forename: Vratika
authors.initials: V
authors.lastname: Agarwal
authors.affiliation: Department of Cardiology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Deshmukh
authors.affiliation: Department of Cardiology, University of Miami, Miami, Florida.
authors.forename: Nileshkumar
authors.initials: N
authors.lastname: Patel
authors.affiliation: Department of Cardiology, Lehigh Valley Health Network, Allentown, Pennsylvania.
authors.forename: Jalaj
authors.initials: J
authors.lastname: Garg
authors.affiliation: Department of Cardiology, Everett Clinic, Everett, Washington.
authors.forename: Apurva
authors.initials: A
authors.lastname: Badheka
authors.affiliation: Department of Cardiology, Lehigh Valley Health Network, Allentown, Pennsylvania.
authors.forename: Matthew
authors.initials: M
authors.lastname: Martinez
authors.affiliation: Department of Cardiology, Lehigh Valley Health Network, Allentown, Pennsylvania.
authors.forename: Nauman
authors.initials: N
authors.lastname: Islam
authors.affiliation: Department of Cardiology, Lehigh Valley Health Network, Allentown, Pennsylvania.
authors.forename: Ronald
authors.initials: R
authors.lastname: Freudenberger
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006353:Heart-Assist Devices / Q000639:trends*; D017052:Hospital Mortality / Q000639:trends*; D061847:Hospitals, High-Volume / Q000639:trends*; D006801:Humans; D038801:International Classification of Diseases / Q000639:trends; D007902:Length of Stay / Q000639:trends; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
keywords: Left ventricular assist device (LVAD); annual hospital volume; continuous flow devices