Transcatheter Versus Surgical Aortic Valve Replacement in Patients With Rheumatic Aortic Stenosis

Association of age-adjusted Charlson comorbidity index with adverse outcomes in patients undergoing transcatheter aortic valve replacement: A retrospective cohort study

Patients undergoing transcatheter aortic valve replacement (TAVR) have a high comorbid burden. Our objective was to assess the association between the age-adjusted Charlson comorbidity index (Age-CCI) and mortality and readmission rates within 1-year post-TAVR. Data were extracted from the Medical Information Mart for Intensive Care IV database (MIMIC-IV version 2.0). The primary endpoint was a composite outcome of all-cause mortality or readmission within 1-year after TAVR. To examine the associations of Age-CCI with outcomes, we used multivariable Cox proportional hazards regression, restricted cubic spline (RCS), and Kaplan-Meier curves. A total of 785 patients (52.9% male) with a median age of 84.0 years were assessed. More than half of our patients had an Age-CCI ≥ 7. After adjustment for potential confounders, we found that a 1 unit increase in Age-CCI was associated with a 10% increase in mortality and readmission rates after TAVR (HR = 1.10, 95% CI: 1.04-1.17, P < .001). High Age-CCI (Age-CCI ≥ 7) compared with the low Age-CCI (Age-CCI < 7) showed a 36% increase of mortality and readmission rates (HR = 1.36, 95% CI: 1.07-1.73, P = .013). The RCS curve analysis showed a continuous linear relationship between Age-CCI and the composite outcome risk (P for non-linearity = .671). The Kaplan-Meier survival analysis showed that patients with Age-CCI ≥ 7 had a poorer prognosis than those with Age-CCI < 7 (log-rank P < .001). Subgroup analyses showed the results remained stable. Age-CCI is independently associated with all-cause mortality and readmission in patients treated with TAVR, which may help clinicians risk-stratify patients and offer an opportunity to improve patient outcomes.

Endocarditis after Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) use is gaining momentum as the mainstay for the treatment of aortic stenosis compared to surgical aortic valve replacement (SAVR). Unfortunately, TAVR-related infective endocarditis (TAVR-IE) is expected to be detected more and more as a result of the ever-expanding indications in younger patients. Given the overall poor prognosis of TAVR-IE, it is imperative that clinicians familiarize themselves with common presentations, major risk factors, diagnostic pitfalls, therapeutic approaches, and the prevention of TAVR-IE. Herein, we review all of the above in detail with the most updated available literature.

Transcatheter heart valve interventions for patients with rheumatic heart disease

Rheumatic heart disease [RHD] is the most prevalent cause of valvular heart disease in the world, outstripping degenerative aortic stenosis numbers fourfold. Despite this, global resources are firmly aimed at improving the management of degenerative disease. Reasons remain complex and include lack of resources, expertise, and overall access to valve interventions in developing nations, where RHD is most prevalent. Is it time to consider less invasive alternatives to conventional valve surgery? Several anatomical and pathological differences exist between degenerative and rheumatic valves, including percutaneous valve landing zones. These are poorly documented and may require dedicated solutions when considering percutaneous intervention. Percutaneous balloon mitral valvuloplasty (PBMV) is the treatment of choice for severe mitral stenosis (MS) but is reserved for patients with suitable valve anatomy without significant mitral regurgitation (MR), the commonest lesion in RHD. Valvuloplasty also rarely offers a durable solution for patients with rheumatic aortic stenosis (AS) or aortic regurgitation (AR). MR and AR pose unique challenges to successful transcatheter valve implantation as landing zone calcification, so central in docking transcatheter aortic valves in degenerative AS, is often lacking. Surgery in young RHD patients requires mechanical prostheses for durability but morbidity and mortality from both thrombotic complications and bleeding on Warfarin remains excessively high. Also, redo surgery rates are high for progression of aortic valve disease in patients with prior mitral valve replacement (MVR). Transcatheter treatments may offer a solution to anticoagulation problems and address reoperation in patients with prior MVR or failing ventricles, but would have to be tailored to the rheumatic environment. The high prevalence of MR and AR, lack of calcification and other unique anatomical challenges remain. Improvements in tissue durability, the development of novel synthetic valve leaflet materials, dedicated delivery systems and docking stations or anchoring systems to securely land the transcatheter devices, would all require attention. We review the epidemiology of RHD and discuss anatomical differences between rheumatic valves and other pathologies with a view to transcatheter solutions. The shortcomings of current RHD management, including current transcatheter treatments, will be discussed and finally we look at future developments in the field.

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.

The Technological Basis of a Balloon-Expandable TAVR System: Non-occlusive Deployment, Anchorage in the Absence of Calcification and Polymer Leaflets

Leaflet durability and costs restrict contemporary trans-catheter aortic valve replacement (TAVR) largely to elderly patients in affluent countries. TAVR that are easily deployable, avoid secondary procedures and are also suitable for younger patients and non-calcific aortic regurgitation (AR) would significantly expand their global reach. Recognizing the reduced need for post-implantation pacemakers in balloon-expandable (BE) TAVR and the recent advances with potentially superior leaflet materials, a trans-catheter BE-system was developed that allows tactile, non-occlusive deployment without rapid pacing, direct attachment of both bioprosthetic and polymer leaflets onto a shape-stabilized scallop and anchorage achieved by plastic deformation even in the absence of calcification. Three sizes were developed from nickel-cobalt-chromium MP35N alloy tubes: Small/23 mm, Medium/26 mm and Large/29 mm. Crimp-diameters of valves with both bioprosthetic (sandwich-crosslinked decellularized pericardium) and polymer leaflets (triblock polyurethane combining siloxane and carbonate segments) match those of modern clinically used BE TAVR. Balloon expansion favors the wing-structures of the stent thereby creating supra-annular anchors whose diameter exceeds the outer diameter at the waist level by a quarter. In the pulse duplicator, polymer and bioprosthetic TAVR showed equivalent fluid dynamics with excellent EOA, pressure gradients and regurgitation volumes. Post-deployment fatigue resistance surpassed ISO requirements. The radial force of the helical deployment balloon at different filling pressures resulted in a fully developed anchorage profile of the valves from two thirds of their maximum deployment diameter onwards. By combining a unique balloon-expandable TAVR system that also caters for non-calcific AR with polymer leaflets, a powerful, potentially disruptive technology for heart valve disease has been incorporated into a TAVR that addresses global needs. While fulfilling key prerequisites for expanding the scope of TAVR to the vast number of patients of low- to middle income countries living with rheumatic heart disease the system may eventually also bring hope to patients of high-income countries presently excluded from TAVR for being too young.

Recent Advances in the Rheumatic Fever and Rheumatic Heart Disease Continuum

Nearly a century after rheumatic fever (RF) and rheumatic heart disease (RHD) was eradicated from the developed world, the disease remains endemic in many low- and middle-income countries (LMICs), with grim health and socioeconomic impacts. The neglect of RHD which persisted for a semi-centennial was further driven by competing infectious diseases, particularly the human immunodeficiency virus (HIV) pandemic. However, over the last two-decades, slowly at first but with building momentum, there has been a resurgence of interest in RF/RHD. In this narrative review, we present the advances that have been made in the RF/RHD continuum over the past two decades since the re-awakening of interest, with a more concise focus on the last decade’s achievements. Such primary advances include understanding the genetic predisposition to RHD, group A Streptococcus (GAS) vaccine development, and improved diagnostic strategies for GAS pharyngitis. Echocardiographic screening for RHD has been a major advance which has unearthed the prevailing high burden of RHD and the recent demonstration of benefit of secondary antibiotic prophylaxis on halting progression of latent RHD is a major step forward. Multiple befitting advances in tertiary management of RHD have also been realized. Finally, we summarize the research gaps and provide illumination on profitable future directions towards global eradication of RHD.

Socioeconomic and Geographic Characteristics of Hospitals Establishing Transcatheter Aortic Valve Replacement Programs, 2012-2018

BACKGROUND

Despite the benefits of novel therapeutics, inequitable diffusion of new technologies may generate disparities. We examined the growth of transcatheter aortic valve replacement (TAVR) in the United States to understand the characteristics of hospitals that developed TAVR programs and the socioeconomic status of patients these hospitals served.

METHODS

We identified fee-for-service Medicare beneficiaries aged 66 years or older who underwent TAVR between January 1, 2012, and December 31, 2018, and hospitals that developed TAVR programs (defined as performing ≥10 TAVRs over the study period). We used linear regression models to compare socioeconomic characteristics of patients treated at hospitals that did and did not establish TAVR programs and described the association between core-based statistical area level markers of socioeconomic status and TAVR rates.

RESULTS

Between 2012 and 2018, 583 hospitals developed new TAVR programs, including 572 (98.1%) in metropolitan areas, and 293 (50.3%) in metropolitan areas with preexisting TAVR programs. Compared with hospitals that did not start TAVR programs, hospitals that did start TAVR programs treated fewer patients with dual eligibility for Medicaid (difference of -2.83% [95% CI, -3.78% to -1.89%], P≤0.01), higher median household incomes (difference $2447 [95% CI, $1348-$3547], P=0.03), and from areas with lower distressed communities index scores (difference -4.02 units [95% CI, -5.43 to -2.61], P≤0.01). After adjusting for the age, clinical comorbidities, race and ethnicity and socioeconomic status, areas with TAVR programs had higher rates of TAVR and TAVR rates per 100 000 Medicare beneficiaries were higher in core-based statistical areas with fewer dual eligible patients, higher median income, and lower distressed communities index scores.

CONCLUSIONS

During the initial growth phase of TAVR programs in the United States, hospitals serving wealthier patients were more likely to start programs. This pattern of growth has led to inequities in the dispersion of TAVR, with lower rates in poorer communities.