AimsMyocardial fibrosis (MF) is a deleterious consequence of aortic valve stenosis (AVS). Global longitudinal strain (GLS) is a novel left ventricular (LV) functional parameter potentially useful to non-invasively estimate MF. MicroRNAs (miRNAs) are non-coding small ribonucleic acids (RNA) modulating genes function, mainly through RNA degradation. miRNA-21 is a biomarker associated with MF in pressure overload. The aim of the present study was to find an integrated algorithm for detection of MF using a combined approach with both bio- and functional markers.MethodsThirty-six patients (75.2 ± 8 y.o.; 63 % Female) with severe AVS and preserved LV ejection fraction (EF), candidate to surgical aortic valve replacement (sAVR) were enrolled. Clinical, bio-humoral evaluation (including plasmatic miRNA-21 collected using specific tubes, PAXgene, for stabilization of peripheral RNA) and a complete echocardiographic study, including GLS and septal strain, were performed before sAVR. Twenty-eight of those patients underwent sAVR and, in 23 of them, an inter-ventricular septum biopsy was performed. Tissues were fixed in formalin and embedded in paraffin. Sections were stained with Hematoxylin and Eosin for histological evaluation and with histochemical Masson trichrome for collagen fibers. The different components were calculated and expressed as micrometers2. To evaluate tissue miRNA components, sections 2-μm thick were cut using a microtome blade for each slide. Regression analysis was performed to test association between dependent variable and various predictors included in the model.ResultsDespite a preserved EF (66 ± 11 %), patients presented altered myocardial deformation parameters (GLS −14,02 ± 3.8 %; septal longitudinal strain, SSL −9.63 ± 2.9 %; septal longitudinal strain rate, SL-Sr −0.58 ± 0.17 1/s; Septal Longitudinal early-diastolic strain rate, SL-SrE 0.62 ± 0.32 1/s). The extent of MF showed an inverse association with both GLS and septal longitudinal deformation indices (GLS: R2 = 0.30; p = 0.02; SSL: R2 = 0.36; p = 0.01; SL-Sr: R2 = 0.39; p < 0.001; SL-SrE: R2 = 0.35; p = 0.001). miRNA-21 was mainly expressed in fibrous tissue (p < 0.0001). A significant association between MF and plasmatic miRNA-21, alone and weighted for measures of structural (LVMi R2 = 0.50; p = 0.0005) and functional (SSL R2 = 0.35; p = 0.006) remodeling, was found.ConclusionsIn AVS, MF is associated with alterations of regional and global strain. Plasmatic miRNA-21 is directly related to MF and associated with LV structural and functional impairment.

Aortic valve stenosis (AVS) represents a cluster of different phenotypes, considering gradient and flow pattern. Circulating micro RNAs may reflect specific pathophysiological processes and could be useful biomarkers to identify disease. We assessed 80 patients (81, 76.7–84 years; 46, 57.5%females) with severe AVS. We performed bio-humoral evaluation (including circulating miRNA-1, 21, 29, 133) and 2D-echocardiography. Patients were classified according to ACC/AHA groups (D1-D3) and flow-gradient classification, considering normal/low flow, (NF/LF) and normal/high gradient, (NG/HG). Patients with reduced ejection fractionwere characterized by higher levels of miRNA1 (p = 0.003) and miRNA 133 (p = 0.03). LF condition was associated with higher levels of miRNA1 (p = 0.02) and miRNA21 (p = 0.02). Levels of miRNA21 were increased in patients with reduced Global longitudinal strain (p = 0.03). LF-HG and LF-LG showed higher levels of miRNA1 expression (p = 0.005). At one-year follow-up miRNA21 and miRNA29 levels resulted significant independent predictors of reverse remodeling and systolic function increase, respectively. Different phenotypes of AVS may express differential levels and types of miRNAs, which may retain a pathophysiological role in pro-hypertrophic and pro-fibrotic processes.

MicroRNAs (miRNAs) are a huge class of noncoding RNAs that regulate protein-encoding genes (degradation/inhibition of translation). miRNAs are nowadays recognized as regulators of biological processes underneath cardiovascular disorders including hypertrophy, ischemia, arrhythmias, and valvular disease. In particular, circulating miRNAs are promising biomarkers of pathology. This review gives an overview of studies in aortic valve stenosis (AS), exclusively considering myocardial remodeling processes. We searched through literature (till September 2016), all studies and reviews involving miRNAs and AS (myocardial compartment). Although at the beginning of a new era, clear evidences exist on the potential diagnostic and prognostic implementation of miRNAs in the clinical setting. In particular, for AS, miRNAs are modulators of myocardial remodeling and hypertrophy. In our experience, here presented in summary, the principal findings of our research were a confirm of the pathophysiological role in AS of miRNA-21, in particular, the interdependence between textural miRNA-21 and fibrogenic stimulus induced by an abnormal left ventricular pressure overload. Moreover, circulating miRNA-21 (biomarker) levels are able to reflect the presence of significant myocardial fibrosis (MF). Thus, the combined evaluation of miRNA-21, a marker of MF, and hypertrophy, together with advanced echocardiographic imaging (two-dimensional speckle tracking), could fulfill many existing gaps, renewing older guidelines paradigms, also allowing a better risk prognostic and diagnostic strategies.