Key Points
- To determine the extent and regional variability of extracellular matrix remodeling, specifically collagen concentration and mature cross-linking, following myocardial infarction.
- Moderate-to-large transmural infarcts were surgically induced in the left ventricular free wall of rats.
- Tissues from the infarct scar, surviving left ventricular free wall, and interventricular septum were harvested 13 weeks post-surgery and compared with age-matched controls.
- Collagen concentration more than doubled in remaining viable free wall (8.92 ± 0.59 vs. 3.95 ± 0.25 mg/100 mg, P < 0.0001) and increased by 27% in the septum (P < 0.01).
- Hydroxylysylpyridinoline cross-linking concentration rose by 60% in viable free wall (P < 0.05) but remained unchanged in the septum, while the scar itself displayed the highest collagen and cross-linking levels.
- Post-infarction hearts developed biventricular hypertrophy, including a ~30% increase in interventricular septum mass compared with controls (247 ± 9 vs. 189 ± 8 mg).
Structured PICO
PPopulationRats with surgically produced moderate-to-large transmural infarcts in the left ventricular (LV) free wall
IInterventionSurgically produced myocardial infarction
CComparatorAge-matched controls
OOutcomeRegional differences in remodeling response of the extracellular matrix (ECM), including collagen concentration and hydroxylysylpyridinoline (HP) concentration at 13 weekssurrogate
Post-myocardial infarction remodeling involves significant regional differences in extracellular matrix changes, highlighting the importance of evaluating both myocytes and the ECM.