title: Effects of continuous-flow versus pulsatile-flow left ventricular assist devices on myocardial unloading and remodeling.
abstract: BACKGROUND
  Continuous-flow left ventricular assist devices (LVAD) are increasingly used for patients with end-stage heart failure (HF). We analyzed the effects of ventricular decompression by continuous-flow versus pulsatile-flow LVADs on myocardial structure and function in this population.
  
  
  RESULTS
  Sixty-one patients who underwent LVAD implantation as bridge-to-transplant were analyzed (pulsatile-flow LVAD: group P, n=31; continuous-flow LVAD: group C, n=30). Serial echocardiograms, serum levels of brain natriuretic peptide (BNP), and extracellular matrix biomarkers (ECM) were compared between the groups. Myocardial BNP and ECM gene expression were evaluated in a subset of 18 patients. Postoperative LV ejection fraction was greater (33.2±12.6% versus 17.6±8.8%, P<0.0001) and the mitral E/E' was lower (9.9±2.6 versus 13.2±3.8, P=0.0002) in group P versus group C. Postoperative serum levels of BNP, metalloproteinases (MMP)-9, and tissue inhibitor of MMP (TIMP)-4 were significantly lower in group P compared with group C (BNP: 552.6±340.6 versus 965.4±805.7 pg/mL, P<0.01; MMP9: 309.0±220.2 versus 475.2±336.9 ng/dL, P<0.05; TIMP4: 1490.9±622.4 versus 2014.3±452.4 ng/dL, P<0.001). Myocardial gene expression of ECM markers and BNP decreased in both groups; however, expression of TIMP-4 decreased only in group P (P=0.024).
  
  
  CONCLUSIONS
  Mechanical unloading of the failing myocardium using pulsatile devices is more effective as indicated by echocardiographic parameters of systolic and diastolic LV function as well as dynamics of BNP and ECM markers. Therefore, specific effects of pulsatile mechanical unloading on the failing myocardium may have important implications for device selection especially for the purpose of bridge-to-recovery in patients with advanced HF.
authors.affiliation: Department of Medicine, Division of Cardiology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Tomoko S
authors.initials: TS
authors.lastname: Kato
authors.forename: Aalap
authors.initials: A
authors.lastname: Chokshi
authors.forename: Parvati
authors.initials: P
authors.lastname: Singh
authors.forename: Tuba
authors.initials: T
authors.lastname: Khawaja
authors.forename: Faisal
authors.initials: F
authors.lastname: Cheema
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Akashi
authors.forename: Khurram
authors.initials: K
authors.lastname: Shahzad
authors.forename: Shinichi
authors.initials: S
authors.lastname: Iwata
authors.forename: Shunichi
authors.initials: S
authors.lastname: Homma
authors.forename: Hiroo
authors.initials: H
authors.lastname: Takayama
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Naka
authors.forename: Ulrich
authors.initials: U
authors.lastname: Jorde
authors.forename: Maryjane
authors.initials: M
authors.lastname: Farr
authors.forename: Donna M
authors.initials: DM
authors.lastname: Mancini
authors.forename: P Christian
authors.initials: PC
authors.lastname: Schulze
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D003971:Diastole / Q000502:physiology; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D006333:Heart Failure / Q000378:metabolism / Q000503:physiopathology* / Q000601:surgery*; D006353:Heart-Assist Devices / Q000145:classification*; D006801:Humans; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D020097:Natriuretic Peptide, Brain / Q000378:metabolism; D012189:Retrospective Studies; D013599:Systole / Q000502:physiology; D019714:Tissue Inhibitor of Metalloproteinases / Q000378:metabolism; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000378:metabolism / Q000503:physiopathology* / Q000601:surgery*; D020257:Ventricular Remodeling / Q000502:physiology*; D000097792:Tissue Inhibitor of Metalloproteinase-4
chemical_list: D015415:Biomarkers; D020780:Matrix Metalloproteinase 9; D020097:Natriuretic Peptide, Brain; D019714:Tissue Inhibitor of Metalloproteinases; D000097792:Tissue Inhibitor of Metalloproteinase-4