Aortic valve: anatomy and structure and the role of vasculature in the degenerative process

Aortic valve stenosis is a degenerative disease affecting increasing number of individuals and characterised by thickening, calcification and fibrosis of the valve resulting in restricted valve motion. Degeneration of the aortic valve is no longer considered a passive deposition of calcium, but an active process that involves certain mechanisms, that is endothelial dysfunction, inflammation, increased oxidative stress, calcification, bone formation, lipid deposition, extracellular matrix (ECM) remodelling and neoangiogenesis. Accumulating evidence indicates an important role for neoangiogenesis (i.e. formation of new vessels) in the pathogenesis of aortic valve stenosis. The normal aortic valve is generally an avascular tissue supplied with oxygen and nutrients via diffusion from the circulating blood. In contrast, presence of intrinsic micro-vasculature has been demonstrated in stenotic and calcified valves. Importantly, presence and density of neovessels have been associated with inflammation, calcification and bone formation. It remains unclear whether neoangiogenesis is a compensatory mechanism aiming to counteract hypoxia and increased metabolic demands of the thickened tissue or represents an active contributor to disease progression. Data extracted mainly from animal studies are supportive of a direct detrimental effect of neoangiogenesis, however, robust evidence from human studies is lacking. Thus, there is inadequate knowledge to assess whether neoangiogenesis could serve as a future therapeutic target for a disease that no effective medical therapy exists. In this review, we present basic aspects of anatomy and structure of the normal and stenotic aortic valve and we focus on the role of valve vasculature in the natural course of valve calcification and stenosis. © 2020 Belgian Society of Cardiology

Multi-slice CT (MSCT) imaging in pretrans-catheter aortic valve implantation (TAVI) screening. How to perform and how to interpret

Aortic valve stenosis (AS) is the most common valvular heart disease among elderly. Trans-catheter aortic valve implantation (TAVI) has become an established and effective alternative therapeutical procedure for inoperable and high-risk patients with symptomatic AS. The procedural success is greatly dependent on a thorough pre-TAVI imaging screening. This requires a comprehensive and multi-modality approach, in which multi-slice computed tomography (MSCT) is the cornerstone in the selection of eligible patients, in choosing the appropriate prosthesis and size, and in mapping the safest access route for the intervention. From our experience of more than 400 TAVI procedures and many more MSCTs for screening purposes, we provide clinical and technical details on the use of MSCT pre-TAVI and brief review of the knowledge so far. © 2017 Hellenic Society of Cardiolog

Transfemoral transcatheter aortic valve replacement in the presence of a mitral prosthesis

PurposeIn the current case series, we present our experience with the self-expanding CoreValve or Evolut R (Medtronic Inc.) in patients with severe symptomatic aortic valve stenosis and concomitant mitral valve prosthesis.MethodsTwelve patients with previous mitral valve prosthesis underwent transcatheter aortic valve replacement for severe symptomatic aortic valve stenosis and/or aortic valve regurgitation. All patients underwent evaluation with an echocardiogram, computed tomography and coronary angiogram. After the index intervention and before discharge all patients underwent transthoracic echocardiography. All outcomes were defined according to the Valve Academic Research Consortium-2 criteria. Results Eleven patients underwent transcatheter aortic valve replacement for severe symptomatic aortic valve stenosis and one patient for severe aortic valve regurgitation. There was immediate improvement of patients' hemodynamic status; no cases of procedural death, stroke, myocardial infarction, or urgent cardiac surgery occurred. There was no 30-day mortality and all patients improved, with 91.6% in functional New York Heart Association class I-II. Conclusion The current study demonstrates that in patients with severe aortic valve stenosis or regurgitation and mitral valve prosthesis, the implantation of a self-expanding aortic valve via the transfemoral route is safe and feasible, with maintained long-term results. © 2019 Italian Federation of Cardiology - I.F.C. All rights reserved

Haemodynamic Issues with Transcatheter Aortic Valve Implantation

Transcatheter aortic valves are typically implanted inside the native (or failed bioprosthetic’s) leaflets, permanently forcing the old leaflets open into a pseudo-cylindrical condition. Due to the passive nature of heart valves, the dynamics of the surrounding fluid environment is critical to their optimum performance. Following intervention, the haemodynamics of the region would ideally be returned to their healthy, physiological state, but major alterations are currently inevitable, such as increased peak flow velocity, the presence of stagnation regions, and increased haemolytic fluid environments. These leaflets reduce the volume of and restrict the flow into the Valsalva’s sinuses, and minimise the development of vortices and associated flow structures, which would aid washout and valve closure. Despite these differences to the healthy condition, implantation of these devices offers much improved flow from that of a moderately stenotic valve, with reduced transvalvular systolic pressure drop, peak blood velocity, and shear stress, which normally outweighs the disadvantages highlighted above, especially for high-risk patients

Assessing the cardiology community position on transradial intervention and the use of bivalirudin in patients with acute coronary syndrome undergoing invasive management: results of an EAPCI survey.

AIMS: Our aim was to report on a survey initiated by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) collecting the opinion of the cardiology community on the invasive management of acute coronary syndrome (ACS), before and after the MATRIX trial presentation at the American College of Cardiology (ACC) 2015 Scientific Sessions. METHODS AND RESULTS: A web-based survey was distributed to all individuals registered on the EuroIntervention mailing list (n=15,200). A total of 572 and 763 physicians responded to the pre- and post-ACC survey, respectively. The radial approach emerged as the preferable access site for ACS patients undergoing invasive management with roughly every other responder interpreting the evidence for mortality benefit as definitive and calling for a guidelines upgrade to class I. The most frequently preferred anticoagulant in ACS patients remains unfractionated heparin (UFH), due to higher costs and greater perceived thrombotic risks associated with bivalirudin. However, more than a quarter of participants declared the use of bivalirudin would increase after MATRIX. CONCLUSIONS: The MATRIX trial reinforced the evidence for a causal association between bleeding and mortality and triggered consensus on the superiority of the radial versus femoral approach. The belief that bivalirudin mitigates bleeding risk is common, but UFH still remains the preferred anticoagulant based on lower costs and thrombotic risks