title: Left atrial decompression pump for severe heart failure with preserved ejection fraction: theoretical and clinical considerations.
abstract: OBJECTIVE
  The purpose of this study was to provide insight into the potential for left atrium (LA) to aortic mechanical circulatory support as a treatment for patients with heart failure with preserved ejection fraction (HFpEF).
  
  
  BACKGROUND
  Although HFpEF arises from different etiologies, 1 hallmark of all forms of this syndrome is a small or minimally-dilated left ventricle (LV). Consequently, the use of traditional mechanical circulatory support in end-stage patients has been difficult. In contrast, HFpEF is also characterized by a large LA.
  
  
  METHODS
  Hemodynamic characteristics of 4 distinct HFpEF phenotypes were characterized from the published data: 1) hypertrophic cardiomyopathies; 2) infiltrative diseases; 3) nonhypertrophic HFpEF; and 4) HFpEF with common cardiovascular comorbidities (e.g., hypertension). Employing a previously-described cardiovascular simulation, the effects of a low-flow, micropump-based LA decompression device were modeled. The effect of sourcing blood from the LV versus the LA was compared.
  
  
  RESULTS
  For all HFpEF phenotypes, mechanical circulatory support significantly increased cardiac output, provided a mild increase in blood pressure, and markedly reduced pulmonary and LA pressures. LV sourcing of blood reduced LV end-systolic volume into a range likely to induce suction. With LA sourcing, however, LV end-systolic volume increased compared with baseline. Due to pre-existing LA enlargement, LA volumes remained sufficiently elevated, thus minimizing the risk of suction.
  
  
  CONCLUSIONS
  This theoretical analysis suggests that a strategy involving pumping blood from the LA to the arterial system may provide a viable option for end-stage HFpEF. Special considerations apply to each of the 4 types of HFpEF phenotypes described. Finally, an HFpEF-specific clinical profile scoring system (such as that of INTERMACS [Interagency Registry for Mechanically Assisted Circulatory Support]) would aid in the selection of patients with the appropriate risk-benefit ratio for implantation of an active pump.
authors.affiliation: HeartWare International, Framingham, Massachusetts; Division of Cardiology, Columbia University, New York, New York. Electronic address: db59@columbia.edu.
authors.forename: Daniel
authors.initials: D
authors.lastname: Burkhoff
authors.affiliation: Division of Cardiology, Columbia University, New York, New York.
authors.forename: Mathew S
authors.initials: MS
authors.lastname: Maurer
authors.affiliation: Division of Cardiology, Washington University, St. Louis, Missouri.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Joseph
authors.affiliation: Division of Cardiology, Duke University, Durham, North Carolina.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Rogers
authors.affiliation: Division of Cardiology, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Edo Y
authors.initials: EY
authors.lastname: Birati
authors.affiliation: Division of Cardiology, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: J Eduardo
authors.initials: JE
authors.lastname: Rame
authors.affiliation: Division of Cardiology, Northwestern University, Chicago, Illinois.
authors.forename: Sanjiv J
authors.initials: SJ
authors.lastname: Shah
mesh_terms: D001013:Aorta, Thoracic; D006325:Heart Atria; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006353:Heart-Assist Devices; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008954:Models, Biological; D013318:Stroke Volume / Q000502:physiology; D013599:Systole
keywords: LVAD; heart failure with preserved ejection fraction; mechanical circulatory support