Transcatheter Aortic Valve Replacement in Rheumatic Aortic Stenosis: A Comprehensive Review

Effective health management strategies for patients undergoing valve replacement: a bibliometric analysis of the current research status and future directions

Background

Valvular heart disease is a major health concern worldwide. The effective management of patients undergoing valve replacement determines their prognosis. Bibliometric analysis of studies on managing patients with artificial heart valves has not been previously performed.

Methods

This study analyzed 2,771 publications related to patient management after valve replacement published in the Web of Science Core Collection database between January 1, 2013, and December 31, 2022. Bibliometric analysis was performed using CiteSpace and VOSviewer considering countries, institutions, authors, journals, references, and keywords.

Results

The countries with the most significant contributions in this field were the United States of America (USA), Germany, and Italy. Leon MB from Columbia University, USA was the most influential author. Transcatheter aortic valve replacement was a current research hotspot, while anticoagulation management was a key area of interest. Combining anticoagulation therapy with internet-linked tools and portable health devices may offer new research avenues. Frailty assessment and intervention were potential future research areas.

Conclusions

This bibliometric analysis provides clinicians and researchers with useful insights for developing novel ideas and directions to manage the health of patients undergoing valve replacement.

Lifetime Management of Patients With Severe Aortic Stenosis in the Era of Transcatheter Aortic Valve Replacement

Aortic stenosis is the most common valvular disease. Surgical aortic valve replacement (SAVR) using mechanical valves has been the preferred treatment for younger patients, but bioprosthetic valves are gaining favour to avoid anticoagulation with warfarin. Transcatheter aortic valve replacement (TAVR) was approved in recent years for the treatment of severe aortic stenosis in intermediate- and low-risk patients as an alternative to SAVR. The longer life expectancy of these groups of patients might exceed the durability of the TAVR or SAVR bioprosthetic valves. Therefore, many patients need 2 or even 3 interventions during their lifetime. Because it has important implications on the feasibility of subsequent procedures, the decision between opting for SAVR or TAVR as the primary procedure requires thorough consideration by the heart team, incorporating patient preferences, clinical indicators, and anatomic aspects. If TAVR is favoured initially, selecting the valve type and determining the implantation level should be conducted, aiming for positive outcomes in the index intervention and keeping in mind the potential for subsequent TAVR-in-TAVR procedures. When SAVR is selected as the primary procedure, the operator must make choices regarding the valve type and the potential need for aortic root enlargement, with the intention of facilitating future valve-in-valve interventions. This narrative review examines the existing evidence concerning the lifelong management of severe aortic stenosis, delving into available treatment strategies, particularly emphasising the initial procedure's selection and its impact on subsequent interventions.

A Rare Case of Congestive Heart Failure due to Isolated Aortic Valve Disease in a Middle-Aged Man Secondary to Rheumatic Fever

Rheumatic heart disease (RHD) is commonly seen in people from developing and low-income countries. More cases are being recorded in developed countries due to migration and globalization. RHD develops in people with a history of rheumatic fever; it is an autoimmune response to group A streptococcal infection due to similarities at the molecular level. Congestive heart failure, arrhythmia, atrial fibrillation, stroke, and infective endocarditis are a few of the many complications associated with RHD. Here we present a case of a 48-year-old male with a past medical history of rheumatic fever at the age of 12 years, who presented to the emergency room (ER) complaining of bilateral ankle swelling, dyspnea on exertion, and palpitations. The patient was tachycardic with a heart rate of 146 beats per minute and tachypneic with a respiratory rate of 22 breaths per minute. On physical exam, there was a harsh systolic and diastolic murmur at the right upper sternal border. A 12-lead electrocardiogram (EKG) revealed atrial flutter with a variable block. Chest X-ray revealed an enlarged cardiac silhouette with a pro-brain natriuretic peptide (proBNP) of 2,772 pg/mL (normal ≤ 125 pg/mL). The patient was stabilized with metoprolol and furosemide and was admitted to the hospital for further investigation. Transthoracic echocardiogram showed left ventricular ejection fraction (LVEF) of 50-55% with severe concentric hypertrophy of the left ventricle with a severely dilated left atrium. Increased thickness of the aortic valve with severe stenosis and a peak gradient of 139 mm Hg and a mean gradient of 82 mm Hg was noted. The valve area was measured to be 0.8 cm². Transesophageal echocardiogram showed a tri-leaflet aortic valve with commissural fusion of valve cusps with severe leaflet thickening consistent with rheumatic valve disease. The patient underwent tissue aortic valve replacement with a bioprosthetic valve. The pathology report showed extensive fibrosis and calcification of the aortic valve. The patient came in for a follow-up visit 6 months later and expressed feeling better and more active.

Identification of MMP9 as a Novel Biomarker to Mitochondrial Metabolism Disorder and Oxidative Stress in Calcific Aortic Valve Stenosis

Calcific aortic valve stenosis (CAVS) is the most common heart valve disorder among humans. To date, no effective method has been identified to prevent this disease. Herein, we aimed to identify novel diagnostic and mitochondria-related biomarkers of CAVS, based on two machine learning algorithms. We further explored their association with infiltrating immune cells and studied their potential function in CAVS. The GSE12644, GSE51472, and GSE83453 expression profiles were downloaded from the Gene Expression Omnibus (GEO) repository. The GSE12644 and GSE51472 datasets were integrated to identify differentially expressed genes (DEGs). GSE12644 contains 10 normal and 10 CAVS samples, whereas GSE51472 contains 5 normal and 10 CAVS samples. GO and KEGG assays of DEGs were conducted, and the correlation between matrix metalloproteinase 9 (MMP9) expression and immune cell infiltration was explored, using CIBERSORT. The LASSO regression model and SVM-RFE analysis were used to identify diagnostic genes. The expression of MMP9 in CAVS and non-CAVS samples was measured using RT-PCR, western blotting and immunohistochemistry. A series of functional experiments were performed to explore the potential role of MMP9 in mitochondrial metabolism and oxidative stress during CAVS progression. Twenty-two DEGs were identified, of which six genes (SCG2, PPBP, TREM1, CCL19, WIF1, and MMP9) were ultimately distinguished as diagnostic genes in CAVS. Of these, MMP9 was indicated as a mitochondria-related gene, the expression and diagnostic value of which were further confirmed in the GSE83453 dataset. Correlation analysis revealed a positive correlation between MMP9 and infiltrating immune cells. In our cohort, MMP9 expression was distinctly increased in CAVS samples, and its inhibition attenuated the calcification of valve interstitial cells (VICs) by suppressing mitochondrial damage and oxidative stress. Taken together, our findings suggest MMP9 as a novel mitochondrial dysfunction biomarker and therapeutic target for CAVS.

Transcatheter aortic valve implantation in patients with rheumatic aortic stenosis

Background

Rheumatic heart disease (RHD) accounts for the highest number of deaths from valvular heart disease globally. Yet, rheumatic aortic stenosis (AS) was excluded from landmark studies investigating the safety and efficacy of transcatheter aortic valve implantation (TAVI). We aimed to describe the clinical and anatomical characteristics of patients with rheumatic AS undergoing TAVI, and to compare procedural and clinical outcomes with patients undergoing TAVI for degenerative AS.

Methods

In a prospective TAVI registry, patients with rheumatic AS were identified based on International Classification of Diseases version 10 codes and/or a documented history of acute rheumatic fever and/or the World Heart Federation criteria for echocardiographic diagnosis of RHD, and were propensity score-matched in a 1:4 ratio to patients with degenerative AS.

Results

Among 2329 patients undergoing TAVI, 105 (4.5%) had rheumatic AS. Compared with patients with degenerative AS, patients with rheumatic AS were more commonly female, older, had higher surgical risk and more commonly suffered from multivalvular heart disease. In the unmatched cohort, both technical success (85.7% vs 85.9%, p=0.887) and 1-year cardiovascular mortality (10.0% vs 8.6%; HR 1.16, 95% CI 0.61 to 2.18, p=0.656) were comparable between patients with rheumatic and degenerative AS. In contrast, patients with rheumatic AS had lower rates of 30-day and 1-year cardiovascular mortality compared with matched patients with degenerative AS (1.9% vs 8.9%, adjusted HR (HRadj) 0.18, 95% CI 0.04 to 0.80, p=0.024; and 10.0% vs 20.3%, HRadj 0.44, 95% CI 0.24 to 0.84, p=0.012, respectively).

Conclusion

TAVI may be a safe and effective treatment strategy for selected elderly patients with rheumatic AS.

Trial registration number

NCT01368250.