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Updated: Jun 25, 2026

Scanning Electron Microscopy of Macerated Tissue to Visualize the Extracellular Matrix
Published on: June 14, 2016
Expression of extracellular matrix genes during myocardial recovery from heart failure after left ventricular assist
Leanne E Felkin1, Enrique Lara-Pezzi, Robert George
1Harefield Heart Science Centre, National Heart and Lung Institute, Imperial College London, Harefield, Middlesex, UK.
Background:
Abnormalities in the extracellular matrix (ECM) can occur in heart failure. In this study we analyzed ECM gene expression in patients with advanced dilated cardiomyopathy who did and did not develop sustained myocardial recovery after left ventricular assist device (LVAD) unloading combined with pharmacologic therapy.
Methods:
Myocardial gene expression of collagens (COL1A1 and COL3A1), fibronectin (FN), matrix metalloproteinases (MMPs 1 to 14), tissue inhibitors of metalloproteinases (TIMPs 1 to 4), connective tissue growth factor (CTGF), transforming growth factor-beta1 (TGF-beta1) and THY1 was measured by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) at LVAD implantation and again at explantation (recovery, n = 11) or transplantation (non-recovery, n = 5).
Results:
The non-recovery group had higher levels of pro-fibrotic markers (COL1A1, TGF-beta1 and THY1) at implantation compared with the recovery group (1.82 +/- 0.74-, 1.81 +/- 0.69- and 3.01 +/- 1.70-fold, respectively; p
Conclusions:
Patients who did not recover had higher myocardial expression of pro-fibrotic genes at LVAD implantation, and in recovered patients higher levels at explant were negatively associated with subsequent ejection fraction. However, individual patients showed complex expression patterns and a decrease in pro-fibrotic markers was not required for recovery.

