Placement of an elastic biodegradable cardiac patch on a subacute infarcted heart leads to cellularization with early developmental cardiomyocyte characteristics

J Card Fail. 2012 Jul;18(7):585-95. doi: 10.1016/j.cardfail.2012.05.006.

Abstract

Background: Placement of an elastic biodegradable patch onto a subacute myocardial infarct (MI) provides temporary elastic support that may act to effectively alter adverse left ventricular (LV) remodeling processes.

Methods: Two weeks after permanent left coronary ligation in Lewis rats, the infarcted anterior wall was covered with polyester urethane urea (MI + PEUU; n = 15) or expanded polytetrafluoroethylene (MI + ePTFE; n = 15) patches, or had no implantation (MI + sham; n = 12). Eight weeks after surgery, cardiac function and histology were assessed.

Results: The ventricular wall in the MI + ePTFE and MI + sham groups was composed of fibrous tissue, whereas PEUU implantation induced α-smooth muscle actin-positive muscle bundles coexpressing sarcomeric α-actinin and cardiac-specific troponin-T. This pattern of colocalization was also found in developing embryonic myocardium. Cardiac transcription factors Nkx-2.5 and GATA-4 were strongly expressed in the muscle bundles. In the MI + sham group, end-diastolic LV cavity area (EDA) increased and the percentage of fractional area change (%FAC) decreased. For ePTFE patched animals, both EDA and %FAC decreased. In contrast, with MI + PEUU patching, %FAC increased and EDA was maintained. With dobutamine-stress echocardiography, MI + PEUU patched LVs possessed contractile reserve significantly larger than the MI + sham group.

Conclusions: MI + PEUU patch implantation onto subacute infarcted myocardium induced muscle cellularization with characteristics of early developmental cardiomyocytes as well as providing a functional reserve.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actins / metabolism
  • Animals
  • Animals, Newborn
  • Biocompatible Materials / administration & dosage*
  • Connexin 43 / metabolism
  • Echocardiography
  • Elasticity
  • Female
  • Fetus
  • Fibrosis
  • GATA4 Transcription Factor / genetics
  • GATA4 Transcription Factor / metabolism
  • Heart / embryology
  • Heart Ventricles / pathology
  • Homeobox Protein Nkx-2.5
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Immunohistochemistry
  • Microscopy, Electron
  • Myocardial Infarction / pathology*
  • Myocardial Infarction / therapy*
  • Myocardium / metabolism*
  • Myocardium / pathology*
  • Polytetrafluoroethylene
  • Polyurethanes
  • RNA, Messenger / metabolism
  • Rats
  • Regeneration
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Troponin T / metabolism
  • Ventricular Remodeling

Substances

  • Actins
  • Biocompatible Materials
  • Connexin 43
  • GATA4 Transcription Factor
  • Homeobox Protein Nkx-2.5
  • Homeodomain Proteins
  • Nkx2-5 protein, mouse
  • Polyurethanes
  • RNA, Messenger
  • Transcription Factors
  • Troponin T
  • polyetherurethane
  • smooth muscle actin, rat
  • Polytetrafluoroethylene