Clinical outcome of TAVR vs SAVR in patients with cardiac amyloidosis

Multimodal preoperative imaging for transcatheter mitral valve replacement in the domestic sheep model

Preclinical in vivo evaluation is an essential step in the progression of new cardiac devices into patient use, with studies predominantly performed in the domestic sheep model. A growing area of interest in cardiac device development is transcatheter mitral valve replacement (TMVR). Clinically, multimodal imaging, or computed tomography (CT) and echocardiography (echo) are used extensively to preoperatively determine mitral valve morphology prior to an intervention, but there is no description on how these modalities can be implemented to support preclinical studies. The purpose of this study is to apply clinically relevant CT and echo acquisition and assessment techniques to a large group of naive research sheep in order to analyze and report modality-related effects on mitral valve dimensional reference intervals in the sheep model. To this end, fifty-five adult domestic sheep underwent preoperative CT and echo exams and resultant images were analyzed using a landmark-based multiplanar measurement protocol and compiled into a master dataset for statistical analysis. We found moderate agreement between CT and echo-derived measurements of the mitral valve in sheep and propose the first clinically-relevant dimensional indices for the sheep's naive mitral valve which can be used to guide future studies evaluating novel TMVR devices. This study is the first of its kind in proposing a reproducible method for detailed examination of the mitral valve in the sheep model using clinically-relevant multimodal imaging. As in patients, CT and echo can reveal accurate native mitral valve dimensions in the sheep prior to preclinical TMVR studies.

Concomitant transthyretin cardiac amyloidosis in patients undergoing TAVR for aortic stenosis: A systemic review and meta-analysis

OBJECTIVE

Transcatheter aortic valve replacement (TAVR) is a successful treatment for aortic stenosis (AS) patients, and previous studies indicate favorable outcomes for those with concomitant aortic stenosis and transthyretin-associated cardiac amyloidosis (TTRCA-AS). However, the impact of TAVR on more adverse outcomes in TTRCA-AS patients compared to those with AS alone is still uncertain, with conflicting findings reported in the literature.

METHODS

PubMed and Scopus were extensively searched from inception till August 2021. Studies were included if they reported data for prevalence and outcomes including mortality and cardiovascular-related hospitalization events in TTRCA-AS patients referred for TAVR. The data for these outcomes were pooled using a random effects model and forest plots were created.

RESULTS

After initially screening 146 articles, 6 were shortlisted for inclusion in our analysis. Pooled analysis demonstrated a 13.3% [95% CI: 10.9-16.5; p = 0.307] prevalence of TTRCA in patients with AS undergoing TAVR. The incidence of mortality and cardiovascular (CV) hospitalization in patients with TTRCA-AS undergoing TAVR were 28.3% [95% CI: 18.7-39.0, p = 0.478] and 21.1% [95% CI: 10.2-34.5, p = 0.211], respectively.

CONCLUSION

The overall pooled TTRCA-AS prevalence was reported to be 13.3% in AS patients who underwent TAVR. Furthermore, transthyretin-associated CA was found to be associated with an increased risk of mortality and hospitalization. Large patient population studies are required to assess the safety and efficacy of TAVR in TTRCA-AS patients, as current research report data from small patient cohorts.

Transcatheter Aortic Valve Replacement (TAVR) Versus Surgical Aortic Valve Replacement (SAVR): A Review on the Length of Stay, Cost, Comorbidities, and Procedural Complications

This review provides an in-depth analysis of the effect of length of stay (LOS), comorbidities, and procedural complications on the cost-effectiveness of transcatheter aortic valve replacement (TAVR) in comparison to surgical aortic valve replacement (SAVR). We found that the average LOS was shorter for patients undergoing TAVR, contributing to lower average costs associated with the procedure, although the LOS varied between patients due to the severity of illness and comorbidities present. TAVR has also been found to improve the quality of life for patients receiving aortic valve replacement compared to SAVR. Although TAVR has a lower rate of most post-operative complications caused by SAVR, such as bleeding and cardiac complications, TAVR shows an increased rate of permanent pacemaker (PPM) implantation due to mechanical trauma on the heart's conduction system. In addition, our findings suggest that the cost-effectiveness of each procedure varies based on the types of valve, the patient history of other medical conditions, and the procedural methods. Our findings show that TAVR is preferred over SAVR in terms of cost-effectiveness across a variety of patients with other coexisting medical conditions, including cancer, advanced kidney disease, cirrhosis, diabetes mellitus, and bundle branch block. TAVR also appears to be superior to SAVR with fewer post-operative complications. However, TAVR appears to have a higher rate of PPM implantation rates as compared to SAVR. The comorbidities of the valve recipient must be considered when deciding whether to use TAVR or SAVR as cost-effectiveness varies with the patient background.

Cardiac amyloidosis and aortic stenosis: a state-of-the-art review

Cardiac amyloidosis is caused by the extracellular deposition of amyloid fibrils in the heart, involving not only the myocardium but also any cardiovascular structure. Indeed, this progressive infiltrative disease also involves the cardiac valves and, specifically, shows a high prevalence with aortic stenosis. Misfolded protein infiltration in the aortic valve leads to tissue damage resulting in the onset or worsening of valve stenosis. Transthyretin cardiac amyloidosis and aortic stenosis coexist in patients > 65 years in about 4-16% of cases, especially in those undergoing transcatheter aortic valve replacement. Diagnostic workup for cardiac amyloidosis in patients with aortic stenosis is based on a multi-parametric approach considering clinical assessment, electrocardiogram, haematologic tests, basic and advanced echocardiography, cardiac magnetic resonance, and technetium labelled cardiac scintigraphy like technetium-99 m (99mTc)-pyrophosphate, 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid, and 99mTc-hydroxymethylene diphosphonate. However, a biopsy is the traditional gold standard for diagnosis. The prognosis of patients with coexisting cardiac amyloidosis and aortic stenosis is still under evaluation. The combination of these two pathologies worsens the prognosis. Regarding treatment, mortality is reduced in patients with cardiac amyloidosis and severe aortic stenosis after undergoing transcatheter aortic valve replacement. Further studies are needed to confirm these findings and to understand whether the diagnosis of cardiac amyloidosis could affect therapeutic strategies. The aim of this review is to critically expose the current state-of-art regarding the association of cardiac amyloidosis with aortic stenosis, from pathophysiology to treatment.

Transcatheter Aortic Valve Implantation in Cardiac Amyloidosis and Aortic Stenosis

Aortic stenosis (AS) and cardiac amyloidosis (CA) occur concomitantly in a significant number of patients and portend a higher risk of all-cause mortality. Previous studies have investigated outcomes in patients with concomitant CA/AS who underwent transcatheter aortic valve implantation (TAVI) versus medical therapy alone, but no evidence-based consensus regarding the ideal management of these patients has been established. Medline, Scopus, and Cochrane Central Register of Controlled Trials were systematically searched to identify relevant studies. Methodologic bias was assessed using the modified Newcastle-Ottawa scale for observational studies. A total of 4 observational studies comprising 83 patients were included. Of these, 45 patients (54%) underwent TAVI, whereas 38 (46%) were managed conservatively. Of the 3 studies that included baseline characteristics by treatment group, 30% were women. The risk of all-cause mortality was found to be significantly lower in patients who underwent TAVI than those treated with conservative medical therapy alone (odds ratio 0.24, 95% confidence interval 0.08 to 0.73). In conclusion, this meta-analysis suggests a lower risk of all-cause mortality in patients with CA with AS who underwent TAVI than those managed with medical therapy alone.