Transcatheter Aortic and Mitral Valve Replacements

Bioprosthetic versus mechanical valves for mitral valve replacement in patients < 70 years: an updated pairwise meta-analysis

BACKGROUND

The ideal conduit for mitral valve replacement (MVR) remains elusive, particularly among younger patients due to increased life expectancy. We perform a pairwise meta-analysis comparing the use of bioprosthetic valves (BPV) and mechanical mitral valves (MMV) in patients < 70 years old undergoing MVR.

METHODS

We comprehensively searched medical databases to identify studies comparing the use of BPV and MMV in patients < 70 years old undergoing MVR. Pairwise meta-analysis was performed using the Mantel-Haenszel method in R version 4.0.2. Outcomes were pooled using the random effect model as risk ratios (RR) with their 95% confidence intervals (95% CI).

RESULTS

16,879 patients from 15 studies were pooled. Compared to MMV, BPV was associated with significantly higher rates of 30-day mortality (RR 1.53, p = 0.0006) but no difference in 30-day stroke (RR 0.70, p = 0.43). At a weighted mean follow-up duration of 14.1 years, BPV was associated with higher rates of long-term mortality (RR 1.28, p = 0.0054). No difference was seen between the two groups for risk of long-term stroke (RR 0.92, p = 0.67), reoperation(RR 1.72, p = 0.12), or major-bleeding (RR 0.57, p = 0.10) at a weighted mean follow-up duration of 11.7, 11.3, and 11.9 years, respectively.

CONCLUSION

The use of MMV in patients < 70 undergoing MVR is associated with lower rates of 30-day/long-term mortality compared to BPV. No significant differences were observed for risk of 30-day/long-term stroke, long-term reoperation, and long-term major bleeding. These findings support the use of MMV in younger patients, although prospective, randomized trials are still needed.

Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021

BACKGROUND

 Transcatheter aortic valve implantation (TAVI) has gained worldwide acceptance and implementation as an alternative therapeutic option in patients with severe aortic valve stenosis unable to safely undergo surgical aortic valve replacement. This transformative technique places the radiologist in a key position in the pre-procedural assessment of potential candidates for this technique, delivering key anatomical information necessary for patient eligibility and procedural safety. Recent trials also provide encouraging results to potentially extend the indication to patients with safer risk profiles.

METHOD

 The review is based on a PubMed literature search using the search terms "transcatheter heart valve", "TAVI", "TAVR", "CT", "imaging", "MR" over a period from 2010-2020, combined with personal comments based on the author's experience.

RESULTS AND CONCLUSION

 CT plays a prominent role in the pre-procedural workup, delivering as a true 3D imaging modality optimal visualization of the complex anatomy of the aortic root with simultaneous evaluation of the patency of the different access routes. As such, the contribution of CT is key for the determination of patient eligibility and procedural safety. This input is supplementary to the contributions of other imaging modalities and forms an important element in the discussions of the Heart Valve Team. Knowledge of the procedure and its characteristics is necessary in order to provide a comprehensive and complete report. While the role of CT in the pre-procedural evaluation is well established, the contribution of CT and MR and the clinical significance of their findings in the routine follow-up after the intervention are less clear and currently the subject of intense investigation. Important issues remain, including the occurrence and significance of subclinical leaflet thrombosis, prosthetic heart valve endocarditis, and long-term structural valve degeneration.

KEY POINTS

  · CT plays a crucial role in evaluating transcatheter heart valve candidates. · Evaluation must include the dimensions of the aortic root and access paths. · The exact post-procedural role of CT and MRI has not yet been determined..

CITATION FORMAT

· Salgado R, El Addouli H, Budde RP. Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021. Fortschr Röntgenstr 2021; 193: 1411 - 1425.

Paravalvular leakage in transcatheter mitral valve replacement: Bringing simulation theory one step closer to reality

Transcatheter mitral valve replacement (TMVR) has emerged as a promising technique for the treatment of these patients with severe mitral valve disease and high or prohibitive surgical risk. Early experience with TMVR has shown a high rate of technical success and promising reductions in the severity of mitral regurgitation sustained out to 1 year post procedure. Despite this, procedural complications remain high, with the most common and significant of these being valve embolization, left ventricualr outflow tract (LVOT) obstruction and paravalvular leakage (PVL). It is this currently unanswered question that Morris et al. start to address in this issue of the Journal. They use the same annular segmentation and valve simulation as already proposed to predict LVOT obstruction, but use it to focus instead on examining the residual gap left between the base of the simulated transcatheter valve and the mitral leaflets or surgical prosthesis.

Evolution of Transcatheter Aortic Valve Replacement | Review of Literature

Aortic valve stenosis is the most common primary valvular heart disease leading to either surgical or transcatheter valve replacement in the United States with its prevalence on the rise due to the elderly population. Over the recent years, the rise of transcatheter aortic valve replacement has been exponential due to technologic developments and randomized control trials. In this review article, we aim to review current literature on transcatheter aortic valve replacements.

Bioprosthetic Heart Valve Degeneration and Dysfunction: Focus on Mechanisms and Multidisciplinary Imaging Considerations

Bioprosthetic heart valves (BPHVs) have fundamentally changed the treatment of valvular heart disease. Despite the continuous progress of BPHVs, from early valve designs for use in surgical replacement to the rapidly evolving use of transcatheter replacement techniques and designs, valve dysfunction and degeneration remain fundamental issues. Current guidelines and proposed standard definitions of BPHV dysfunction and degeneration outline the importance of imaging. Imaging plays a key role in understanding valve degeneration, including clinical imaging to identify transvalvular gradients, leaflet thickening, thrombosis, calcification, and restricted or reduced leaflet motion. Similarly, translational imaging approaches-including micro-CT, high-speed video, computational modeling, and high-resolution microscopy-and histologic analysis are crucial to understanding mechanisms of valve degeneration and factors that may contribute to valve dysfunction. This article provides an overview of valve dysfunction and degeneration and the role of imaging. © RSNA, 2019.