title: Early and late results of left ventricular reshaping by passive cardiac-support device in canine heart failure.
abstract: BACKGROUND
  We tested whether the CardioClasp, a passive non-blood-contacting device could decrease excessive geometric burden in dilated cardiomyopathy and improve left ventricular systolic function and contractility by reshaping the left ventricle (LV) and by decreasing LV wall stress (LVWS) without decreasing arterial blood pressure.
  
  
  METHODS
  In mongrel dogs (n = 6, the early group; n = 6, the chronic group; 25-27 kg), 4 weeks of rapid right ventricular pacing (210 to 240 bpm) induced dilated cardiomyopathy with heart failure. In the early group, we used hemodynamic data and echocardiography to evaluate LV systolic function immediately after placing the CardioClasp device. In the chronic group, we also evaluated LV systolic function immediately after placing the device on dilated hearts and then left the device in place for 30 days. At the end of 30 days, before explantation of the device, we again assessed LV systolic function. We measured fractional area of contraction (FAC), LVWS, and hemodynamic data in both groups.
  
  
  RESULTS
  In the early group, use of the CardioClasp device decreased the LV end-diastolic anterior-to-posterior dimension by 27.8% +/- 2.6% at implantation (p < 0.05). In the chronic group, use of the CardioClasp decreased the LV end-diastolic anterior-to-posterior dimension by 19.4% +/- 2.0% at implantation (p < 0.05) and by 22.0% +/- 3.10% at explantation (p < 0.05). Use of the CardioClasp did not alter LV end-diastolic and peak pressure, LV dP/dts, or cardiac output at implantation or at explantation. In the early group, use of the CardioClasp decreased the LVWS by 43.4% +/- 3.1% at implantation (p < 0.05). In the chronic group, LVWS decreased by 28.8% +/- 2.1% at implantation (p < 0.05) and by 43.3% +/- 5.2% at explantation (p < 0.05). In the early group, FAC increased significantly, by 28.9% +/- 7.8% at implantation (p < 0.05). In the chronic group, FAC increased significantly, by 18% +/- 12% at implantation (p < 0.05) and by 19% +/- 12% at explantation (p < 0.05).
  
  
  CONCLUSIONS
  As expected, use of the CardioClasp device increased FAC and decreased LVWS by reshaping the LV. Use of the CardioClasp device maintained cardiac output and arterial pressure. In 30-day experiments, the increased FAC and decreased LVWS were maintained at explantation.
authors.affiliation: Cardiology Section, Temple University, Philadelphia, Pennsylvania, USA. mkashem@temple.edu
authors.forename: Abul
authors.initials: A
authors.lastname: Kashem
authors.forename: Sarmina
authors.initials: S
authors.lastname: Kashem
authors.forename: William P
authors.initials: WP
authors.lastname: Santamore
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Crabbe
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Margulies
authors.forename: David B
authors.initials: DB
authors.lastname: Melvin
authors.forename: Bruce I
authors.initials: BI
authors.lastname: Goldman
mesh_terms: D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000601:surgery / Q000628:therapy*; D004195:Disease Models, Animal; D004285:Dogs; D004452:Echocardiography; D006353:Heart-Assist Devices; D006439:Hemodynamics; D020257:Ventricular Remodeling