Myocardial interstitial remodelling in non-ischaemic dilated cardiomyopathy: insights from cardiovascular magnetic resonance

Abstract

Myocardial remodelling involves not only the myocytes, but also non-myocyte cells and the extracellular matrix, which constitutes around 6 % of the normal heart and includes fluid, collagen and glycoproteins. In non-ischaemic dilated cardiomyopathy (DCM), the cardiac interstitium increases as a result of diffuse interstitial (microscopic) fibrosis, post-necrotic replacement (macroscopic) fibrosis or myocardial oedema. The activation of the renin-angiotensin-aldosterone system is a major determinant of fibroblasts activation and collagen deposition, with the transforming growth factor β as the downstream signal mediator. Endomyocardial biopsy still represents the current reference method for interstitial and replacement myocardial fibrosis assessment, but cardiovascular magnetic resonance (CMR) allows in vivo detection of macroscopic fibrosis with post-contrast late enhancement imaging. Moreover, recent pre- and post-contrast T1 mapping techniques provide a quantitative estimation of myocardial interstitial remodelling, with potential diagnostic and prognostic clinical utility. Here, we review the pathophysiological mechanisms of myocardial interstitial remodelling in DCM, its non-invasive characterization with biomarkers and with CMR, as well as the most recent studies about their clinical utility.

Renal Denervation Attenuates Multi-Organ Fibrosis and Improves Vascular Remodeling in Rats with Transverse Aortic Constriction Induced Cardiomyopathy

“…Moreover, vascular remodeling plays an important role in the pathogenesis and progression of atherosclerosis, hypertension and cardiovascular diseases [27]. PINP and PIIINP are regarded as the biomarkers of collagen types I and III synthesis as they are products during collagen production [2]. In our study, RDN attenuated LA, LV, tubulointerstitial, glomerular and hepatic fibrosis as well as improved vascular remodeling.…”

“…Cardiac pressure overload leads to maladaptive myocardial remodeling, including cardiac hypertrophy, systolic and diastolic dysfunction as well as fibrosis [1,2]. Cardiac dysfunction can cause kidney and liver damage [3,4].…”

Myocardial T1 and T2 Mapping: Techniques and Clinical Applications

“…The myocardium can be divided into its cellular and extracellular or interstitial components (2930). The cellular components include cardiac muscles (involuntary striated muscle fibers), which are interconnected by intercalated discs, structural components, nuclei, sarcolemma, sarcoplasmic reticulum, and vascular and neuronal elements.…”

Myokardfibrose

“…Fibrosebedømming med MR viser god korrelasjon mot histologi (7,10,11,15,25). Hjerte-MR kan betegnes som en mer praktisk gjennomførbar gullstandard for fibrosepåvisning (11,26).…”

“…Kardial amyloidose, som også betegnes som infiltrerende interstitiell fibrose (7,16), innebaerer amyloidavleiring i myokard. Tilstanden oppstår, i motsetning til tradisjonell myokardfibrose, uavhengig av kardial belastning (11).…”