Novel Approaches in Cardiac Imaging for Non-invasive Assessment of Left Heart Myocardial Fibrosis

Abstract

In the past, the identification of myocardial fibrosis was only possible through invasive histologic assessment. Although endomyocardial biopsy remains the gold standard, recent advances in cardiac imaging techniques have enabled non-invasive tissue characterization of the myocardium, which has also provided valuable insights into specific disease processes. The diagnostic accuracy, incremental yield and prognostic value of speckle tracking echocardiography, late gadolinium enhancement and parametric mapping modules by cardiac magnetic resonance and cardiac computed tomography have been validated against tissue samples and tested in broad patient populations, overall providing relevant clinical information to the cardiologist. This review describes the patterns of left ventricular and left atrial fibrosis, and their characterization by advanced echocardiography, cardiac magnetic resonance and cardiac computed tomography, allowing for clinical applications in sudden cardiac death and management of atrial fibrillation.

SGLT2 Inhibition in HFpEF. Do We Need More Quantitative and Load Independent Metrics to Understand the Results of the EMPEROR-Preserved Trial?

“…From a pathophysiologic point of view, LVEF is a crude and load-dependent marker for cardiac efficiency (5,6), whereas myocardial strain by echocardiography and advanced quantitative CMR, recently exhibited important value for the non-invasive assessment of myocardial fibrosis and incremental prognostic value beyond LVEF in heart failure patients (6)(7)(8). Thus, global longitudinal strain (GLS) was associated with clinical heart failure status, the level of neurohormonal activation and with long-term cardiac mortality in patients with asymptomatic and symptomatic heart failure (6).…”

“…In the same direction, CMR T1 mapping techniques allow for the assessment of interstitial space characteristics and extracellular volume size, which are related to collagen content and interstitial infiltration of myocardial tissue by fibrotic tissue or other molecules, such as amyloid. The ability of such measures for the risk stratification of patients with heart failure, cardiomyopathies or amyloidosis has already been demonstrated (8)(9)(10)(11). In addition, recent studies highlighted the ability of such techniques to accurately assess longitudinal changes of myocardial extracellular volume in patients treated with SGLT2 inhibitors (12,13).…”

Left atrial strain — a current clinical perspective

“…It provides reliable estimates of myocardial deformation with further accuracy, thanks to the recent advent of dedicated software packages. Measurements of atrial strain using STE are well-validated [10,11] and, notably, correlated with the histologically proven fibrotic remodeling of the LA wall [12][13][14]. However, the results obtained with different echocardiographic machines and post-processing software packages should be interpreted with caution because vendor variability is not well studied yet.…”

Investigating the possible mechanisms of pirfenidone to be targeted as a promising anti-inflammatory, anti-fibrotic, anti-oxidant, anti-apoptotic, anti-tumor, and/or anti-SARS-CoV-2

“…Myocardial fibrosis is a natural response to a variety of cardiac stressors that can become maladaptive over time and contribute to the genesis and progression of heart failure [76] . Excess collagen buildup causes ECM expansion, which is thought to be a fundamental pathophysiological mechanism of HFpEF, a common pathway that exists regardless of aetiology.…”