Biomechanical assessment of remote and postinfarction scar remodeling following myocardial infarction

Sci Rep. 2019 Nov 14;9(1):16744. doi: 10.1038/s41598-019-53351-7.

Abstract

The importance of collagen remodeling following myocardial infarction (MI) is extensively investigated, but little is known on the biomechanical impact of fibrillar collagen on left ventricle post-MI. We aim to identify the significant effects of the biomechanics of types I, III, and V collagen on physio-pathological changes of murine hearts leading to heart failure. Immediately post-MI, heart reduces its function (EF = 40.94 ± 2.12%) while sarcomeres' dimensions are unchanged. Strikingly, as determined by immunohistochemistry staining, type V collagen fraction significantly grows in remote and scar for sustaining de novo-types I and III collagen fibers' assembly while hindering their enzymatic degradation. Thereafter, the compensatory heart function (EF = 63.04 ± 3.16%) associates with steady development of types I and III collagen in a stiff remote (12.79 ± 1.09 MPa) and scar (22.40 ± 1.08 MPa). In remote, the soft de novo-type III collagen uncoils preventing further expansion of elongated sarcomeres (2.7 ± 0.3 mm). Once the compensatory mechanisms are surpassed, the increased turnover of stiff type I collagen (>50%) lead to a pseudo-stable biomechanical regime of the heart (≅9 MPa) with reduced EF (50.55 ± 3.25%). These end-characteristics represent the common scenario evidenced in patients suffering from heart failure after MI. Our pre-clinical data advances the understanding of the cause of heart failure induced in patients with extended MI.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cicatrix / metabolism*
  • Cicatrix / physiopathology
  • Collagen Type I / metabolism*
  • Collagen Type III / metabolism*
  • Collagen Type V / metabolism*
  • Disease Models, Animal
  • Heart Function Tests
  • Humans
  • Male
  • Mice
  • Myocardial Infarction / metabolism
  • Myocardial Infarction / physiopathology*

Substances

  • Collagen Type I
  • Collagen Type III
  • Collagen Type V