Long-term Follow-up After Transcatheter Aortic Valve Implantation for Severe Aortic Stenosis

Transcatheter aortic valve replacements alter circulating serum factors to mediate myofibroblast deactivation

The transcatheter aortic valve replacement (TAVR) procedure has emerged as a minimally invasive treatment for patients with aortic valve stenosis (AVS). However, alterations in serum factor composition and biological activity after TAVR remain unknown. Here, we quantified the systemic inflammatory effects of the TAVR procedure and hypothesized that alterations in serum factor composition would modulate valve and cardiac fibrosis. Serum samples were obtained from patients with AVS immediately before their TAVR procedure (pre-TAVR) and about 1 month afterward (post-TAVR). Aptamer-based proteomic profiling revealed alterations in post-TAVR serum composition, and ontological analysis identified inflammatory macrophage factors implicated in myofibroblast activation and deactivation. Hydrogel biomaterials used as valve matrix mimics demonstrated that post-TAVR serum reduced myofibroblast activation of valvular interstitial cells relative to pre-TAVR serum from the same patient. Transcriptomics and curated network analysis revealed a shift in myofibroblast phenotype from pre-TAVR to post-TAVR and identified p38 MAPK signaling as one pathway involved in pre-TAVR–mediated myofibroblast activation. Post-TAVR serum deactivated valve and cardiac myofibroblasts initially exposed to pre-TAVR serum to a quiescent fibroblast phenotype. Our in vitro deactivation data correlated with patient disease severity measured via echocardiography and multimorbidity scores, and correlations were dependent on hydrogel stiffness. Sex differences in cellular responses to male and female sera were also observed and may corroborate clinical observations regarding sex-specific TAVR outcomes. Together, alterations in serum composition after TAVR may lead to an antifibrotic fibroblast phenotype, which suggests earlier interventions may be beneficial for patients with advanced AVS to prevent further disease progression.

Transcatheter aortic valve replacement alters a patient’s serum proteome, reversing valvular interstitial cell and cardiac myofibroblast activation.

Aortic valve stenosis (narrowing of the aortic valve) contributes to inadequate blood flow, fibrosis, hypertrophy, and, ultimately, heart failure. Transcatheter aortic valve replacement (TAVR) improves blood flow, but little is known about cardiac remodeling after the procedure. Aguado and colleagues performed proteomics on serum samples collected from patients before and after TAVR and studied the effects of serum on valve and cardiac cells using hydrogel culture platforms. A role for p38 MAPK signaling in activating cells was identified using pre-TAVR serum, whereas post-TAVR serum returned cells to a quiescent state. Along with preliminary insights into sex-specific differences, the authors’ research supports a role for TAVR-induced alteration of circulating inflammatory cytokines in regulating valve cell phenotype.

How TAVI registries report clinical outcomes-A systematic review of endpoints based on VARC-2 definitions

Introduction

Transcatheter aortic valve implantation (TAVI) has been demonstrated to be an alternative treatment for severe aortic stenosis in patients considered as high surgical risk. Since its first human implantation by Cribier et al., TAVI has been shown to increase survival rate and quality of life for high surgical risks patients. The objective of this study is to provide an overview of TAVI registries and the reporting clinical outcomes based on the VARC-2 definitions. In addition, the comparability and adherence of VARC-2 reporting within the identified TAVI registries was reviewed.

Materials and methods

A systematic review of TAVI registries reporting VARC-2 definitions has been performed in line with PRISMA guidelines in PubMed, ScienceDirect, Scopus databases and EMBASE. Based on VARC-2, patients’ characteristics and procedure characteristics, 30-day clinical outcomes, 1-year mortality and composited endpoints were extracted from each registry’s publications.

Results

This review identified 466 studies that were potentially relevant, and 20 TAVI registries reported VARC-2 definitions involved in our present review. Of all 20 registries, an overall sample size of 12,583 patients was involved. The 30-day all-cause mortality ranged from 0 to 12.7%. From 20 registries, 14 registries reported the cardiovascular mortality at 30 days. 9 registries reported myocardial infarction (MI) rate based on VARC-2 definitions, and 7 registries reported peri-procedural MI rate (<72h). In our review, most of registries presented MI rates ranging from 0.5% to 2%. The majority of registries have reported complications such as bleeding, vascular complications and new pacemaker implantation.

Conclusion

Since the introduction of VARC definitions from 2011, VARC and VARC-2 definitions are still not systematically used by all TAVI studies. These endpoint definitions warrant a concise and systemic analysis of outcome measures. Reporting TAVI-outcome uniformly makes study result comparison feasible. This definitely will increase patient safety, additionally to provide sufficient evidence to support decision makers like regulatory bodies, HTA agencies, payers.

Long term outcomes of transcatheter aortic valve implantation (TAVI): a systematic review of 5-year survival and beyond

BACKGROUND

Transcatheter aortic valve implantation/replacement (TAVI/TAVR) is becoming more frequently used to treat aortic stenosis (AS), with increasing push for the procedure in lower risk patients. Numerous randomized controlled trials have demonstrated that TAVI offers a suitable alternative to the current gold standard of surgical aortic valve replacement (SAVR) in terms of short-term outcomes. The present review evaluates long-term outcomes following TAVI procedures.

METHODS

Literature search using three electronic databases was performed up to June 2017. Studies which included 20 or more patients undergoing TAVI procedures, either as a stand-alone or concomitant procedure and with a follow-up of at least 5 years, were included in the present review. Literature search and data extraction were performed by two independent researchers. Digitized survival data were extracted from Kaplan-Meier curves in order to re-create the original patient data using an iterative algorithm and subsequently aggregated for analysis.

RESULTS

Thirty-one studies were included in the present analysis, with a total of 13,857 patients. Two studies were national registries, eight were multi-institutional collaborations and the remainder were institutional series. Overall, 45.7% of patients were male, with mean age of 81.5±7.0 years. Where reported, the mean Logistic EuroSCORE (LES) was 22.1±13.7 and the mean Society of Thoracic Surgeons (STS) score was 9.2±6.6. The pooled analysis found 30-day mortality, cerebrovascular accidents, acute kidney injury (AKI) and requirement for permanent pacemaker (PPM) implantation to be 8.4%, 2.8%, 14.4%, and 13.4%, respectively. Aggregated survival at 1-, 2-, 3-, 5- and 7-year were 83%, 75%, 65%, 48% and 28%, respectively.

CONCLUSIONS

The present systematic review identified acceptable long-term survival results for TAVI procedures in an elderly population. Extended follow-up is required to assess long-term outcomes following TAVI, particularly before its application is extended into wider population groups.