Imaging of the mitral valve: role of echocardiography, cardiac magnetic resonance, and cardiac computed tomography

Degenerative mitral regurgitation

Degenerative mitral regurgitation is a major threat to public health and affects at least 24 million people worldwide, with an estimated 0.88 million disability-adjusted life years and 34,000 deaths in 2019. Improving access to diagnostic testing and to timely curative therapies such as surgical mitral valve repair will improve the outcomes of many individuals. Imaging such as echocardiography and cardiac magnetic resonance allow accurate diagnosis and have provided new insights for a better definition of the most appropriate timing for intervention. Advances in surgical techniques allow minimally invasive treatment with durable results that last for ≥20 years. Transcatheter therapies can provide good results in select patients who are considered high risk for surgery and have a suitable anatomy; the durability of such repairs is up to 5 years. Translational science has provided new knowledge on the pathophysiology of degenerative mitral regurgitation and may pave the road to the development of medical therapies that could be used to halt the progression of the disease.

Transcatheter Mitral Valve Repair or Replacement: Competitive or Complementary?

Over the last two decades, transcatheter devices have been developed to repair or replace diseased mitral valves (MV). Transcatheter mitral valve repair (TMVr) devices have been proven to be efficient and safe, but many anatomical structures are not compatible with these technologies. The most significant advantage of transcatheter mitral valve replacement (TMVR) over transcatheter repair is the greater and more reliable reduction in mitral regurgitation. However, there are also potential disadvantages. This review introduces the newest TMVr and TMVR devices and presents clinical trial data to identify current challenges and directions for future research.

Characterization of Degenerative Mitral Valve Disease: Differences between Fibroelastic Deficiency and Barlow's Disease

Degenerative mitral valve disease causing mitral valve prolapse is the most common cause of primary mitral regurgitation, with two distinct phenotypes generally recognized with some major differences, i.e., fibroelastic deficiency (FED) and Barlow’s disease. The aim of this review was to describe the main histological, clinical and echocardiographic features of patients with FED and Barlow’s disease, highlighting the differences in diagnosis, risk stratification and patient management, but also the still significant gaps in understanding the exact pathophysiology of these two phenotypes.

"Learning curve and procedural volume in mitral valve disease"

The impact of procedural volume on outcome results is a widespread topic in surgery, The importance of referral centers and high-volume hospitals have reached the forefront, particularly in mitral valve surgery, impacting the recommendations of the latest European and American guidelines. In this issue, Wayne et al. presented an interesting analysis of the relationship between surgeon and hospital procedural volume, mitral valve repair rates, and 30-day mortality for degenerative mitral regurgitation (MR) in Australia. Based on the database of the Australian and New Zealand Society of Cardiac and Thoracic Surgeons, they have shown how the surgeon and hospital caseload are significantly associated with repair rates of degenerative MR. This study reaches the same results presented by Chikwe et al. and others and corroborates what guidelines reported about the need for referral centers for mitral valve disease. These results are the reasons why many surgeons, as Adams et al., published papers to highlight the importance of a minimum mitral valve surgery volume threshold to achieve optimum results and discourage at the same time low-volume centers. The concept of minimum thresholds in mitral surgery suggested by Wayne et al. and previously by Vassileva et al. is fundamental to guarantee periprocedural safety, accuracy, and a high rate of reparation. Moreover, not only hospital volume but also surgeon yearly number of mitral valve interventions are crucial in valve repair rate and the threshold of 20 mitral procedures per year, proposed by Wayne et al., seems absolutely consistent with the literature.