Update on Transcatheter Tricuspid Valve Replacement Therapies

Severe tricuspid regurgitation is relatively common, especially in the elderly, and portends poor survival. Neither medical therapy nor conventional surgery is efficacious for most patients. In contrast, transcatheter tricuspid valve interventions are showing promise to improve quality of life and mortality. Although there is more clinical experience with transcatheter tricuspid valve repair, there are many patients for which repair is either not possible or cannot optimally reduce the severity of tricuspid regurgitation. Transcatheter tricuspid valve replacement is rapidly emerging and may ultimately become the preferred treatment option. In this review, we discuss transcatheter tricuspid valve replacement, analyze the devices in development and in clinical trials, and highlight the advantages and drawbacks of transcatheter tricuspid valve replacement vs. repair.

Bacterial infiltration in structural heart valve disease

OBJECTIVES

The pathology of structural valvular heart disease (sVHD) ranges from basic diseases of rheumatologic origin to chronic degenerative remodeling processes after acute bacterial infections. Molecular genetic methods allow detection of the complete microbial spectrum in heart valve tissues independent of microbiological cultivation. In particular, whole-metagenome analysis is a sensitive and highly specific analytical method that allows a deeper insight into the pathogenicity of the diseases. In the present study we assessed the pathogen spectrum in heart valve tissue from 25 sVHD patients using molecular and microbiological methods.

METHODS

Twenty-five sVHD patients were selected randomly from an observational cohort study (March 2016 to January 2017). The explanted native heart valves were examined using microbiological methods and immunohistological structural analysis. In addition, the bacterial metagenome of the heart valve tissue was determined using next-generation sequencing.

RESULTS

The use of sonication as a pretreatment of valve tissue from 4 sVHD patients permitted successful detection of Clostridium difficile, Enterococcus faecalis, Staphylococcus saccharolyticus, and Staphylococcus haemolyticus using microbial cultivation. Histological staining revealed intramural localization. Metagenome analysis identified a higher rate of bacterial infiltration in 52% of cases. The pathogen spectrum included both gram-positive and gram-negative bacteria.

CONCLUSIONS

Microbiological and molecular biological studies are necessary to detect the spectrum of bacteria in a calcified heart valve. Metagenome analysis is a valid method to gain new insight into the polymicrobial pathophysiology of sVHD. Our results suggest that an undetected proportion of sVHD might be triggered by chronic inflammation or influenced by secondary bacterial infiltration.