Aortic Stenosis

Multimodality imaging in valvular heart disease: how to use state-of-the-art technology in daily practice

Our understanding of the complexities of valvular heart disease (VHD) has evolved in recent years, primarily because of the increased use of multimodality imaging (MMI). Whilst echocardiography remains the primary imaging technique, the contemporary evaluation of patients with VHD requires comprehensive analysis of the mechanism of valvular dysfunction, accurate quantification of severity, and active exclusion extravalvular consequences. Furthermore, advances in surgical and percutaneous therapies have driven the need for meticulous multimodality imaging to aid in patient and procedural selection. Fundamental decision-making regarding whom, when, and how to treat patients with VHD has become more complex. There has been rapid technological advancement in MMI; many techniques are now available in routine clinical practice, and their integration into has the potential to truly individualize management strategies. This review provides an overview of the current evidence for the use of MMI in VHD, and how various techniques within each modality can be used practically to answer clinical conundrums.

The Role of Extravalvular Cardiac Damage Staging in Aortic Valve Disease Management

Current management of patients with aortic valve disease, including aortic valve stenosis (AS), aortic valve regurgitation (AR), and mixed aortic valve disease (MAVD), remains challenging. American and European guideline recommendations regarding the timing of intervention are mainly based on the assessment of disease severity (ie, grading), presence of symptoms related to aortic valve disease, left ventricular systolic dysfunction, or LV enlargement. Furthermore, the decision regarding the type of intervention (ie, surgical vs transcatheter) is primarily based on risk assessment from surgical risk scores. There is, however, less emphasis on the importance of the assessment of anatomic and functional cardiac repercussions of aortic valve disease to guide the clinical management of these patients. Recently, a novel approach has been proposed to improve the management of aortic valve disease with 2 main components for risk stratification of the disease: 1) grading the severity of aortic valve disease, and 2) staging the extent of extravalvular cardiac damage associated with aortic valve disease with the use of echocardiography. To date, this novel approach of extravalvular cardiac damage staging was proposed and validated only in the context of AS but could be extended to other valvular heart diseases, including AR and MAVD. Further studies are also needed to test the incremental value of additional imaging parameters (eg, myocardial fibrosis by magnetic resonance) as well as blood biomarkers (eg, natriuretic peptide, cardiac troponin, and others) to the existing cardiac damage staging schemes.

Discordant Echocardiographic Grading in Low Gradient Aortic Stenosis (DEGAS Study) From the Italian Society of Echocardiography and Cardiovascular Imaging Research Network: Rationale and Study Design

Background

Low-gradient aortic stenosis (LG-AS) is characterized by the combination of an aortic valve area compatible with severe stenosis and a low transvalvular mean gradient with low-flow state (i.e., indexed stroke volume <35 mL/m²) in the presence of reduced (classical low-flow AS) or preserved (paradoxical low-flow AS) ejection fraction. Furthermore, the occurrence of a normal-flow LG-AS is still advocated by many authors. Within this diagnostic complexity, the diagnosis of severe AS remains challenging.

Objective

The general objective of the Discordant Echocardiographic Grading in Low-gradient AS (DEGAS Study) study will be to assess the prevalence of true severe AS in this population and validate new parameters to improve the assessment and the clinical decision-making in patients with LG-AS.

Methods and Analyses

The DEGAS Study of the Italian Society of Echocardiography and Cardiovascular Imaging is a prospective, multicenter, observational diagnostic study that will enroll consecutively adult patients with LG-AS over 2 years. AS severity will be ideally confirmed by a multimodality approach, but only the quantification of calcium score by multidetector computed tomography will be mandatory. The primary clinical outcome variable will be 12-month all-cause mortality. The secondary outcome variables will be (i) 30-day mortality (for patients treated by Surgical aortic valve replacement or TAVR); (ii) 12-month cardiovascular mortality; (iii) 12-month new major cardiovascular events such as myocardial infarction, stroke, vascular complications, and rehospitalization for heart failure; and (iv) composite endpoint of cardiovascular mortality and hospitalization for heart failure. Data collection will take place through a web platform (REDCap), absolutely secure based on current standards concerning the ethical requirements and data integrity.