Management strategies and future challenges for aortic valve disease

Calcific Aortic Valve Disease: a Developmental Biology Perspective

PURPOSE OF REVIEW

This review aims to highlight the past and more current literature related to the multifaceted pathogenic programs that contribute to calcific aortic valve disease (CAVD) with a focus on the contribution of developmental programs.

RECENT FINDINGS

Calcification of the aortic valve is an active process characterized by calcific nodule formation on the aortic surface leading to a less supple and more stiffened cusp, thereby limiting movement and causing clinical stenosis. The mechanisms underlying these pathogenic changes are largely unknown, but emerging studies have suggested that signaling pathways common to valvulogenesis and bone development play significant roles and include Transforming Growth Factor-β (TGF-β), bone morphogenetic protein (BMP), Wnt, Notch, and Sox9. This comprehensive review of the literature highlights the complex nature of CAVD but concurrently identifies key regulators that can be targeted in the development of mechanistic-based therapies beyond surgical intervention to improve patient outcome.

Association between apolipoprotein B genetic polymorphism and the risk of calcific aortic stenosis in Chinese subjects, in Xinjiang, China

Background

Limited information is available when it comes to the impact of genetic on Calcific Aortic Stenosis (CAS). Apolipoprotein B (apoB) is a key component in lipid metabolism and plays an important role in the dynamic equilibrium of cholesterol. We performed a case–control study to explore the association of apoB genetic polymorphisms with CAS in Chinese subjects, in Xinjiang, China.

Methods

We designed a case-control study including 314 CAS patients and 652 age- and sex-matched control subjects. Using the polymerase chain reaction-restriction fragment length (PCR-RFLP) method, we genotyped two SNPs (rs6725189 and rs693) of apoB gene in all subjects.

Results

We found that the rs693 T allele was associated with a significantly elevated CAS risk [TT/CT vs. CC: adjusted odds ratio (AOR) = 1.58, 95% confidence interval (CI) = 1.82–2.10, P = 0.002] and the rs6725189 T allele was also associated with a significantly elevated CAS risk (GT vs. GG: AOR = 1.82, 95% CI = 1.14–2.92, P = 0.013). Furthermore, we also found that the TC levels were significantly higher in rs693 TT/CT genotypes than that in CC genotypes (P < 0.05).

Conclusions

Both rs693 and rs6725189 of the apoB gene are associated with CAS in Chinese subjects, in Xinjiang, China.

Comprehensive geriatric assessment in patients undergoing transcatheter aortic valve implantation - results from the CGA-TAVI multicentre registry

Background

In older patients with aortic stenosis (AS) undergoing TAVI, the potential role of prior CGA is not well established. To explore the value of comprehensive geriatric assessment (CGA) for predicting mortality and/or hospitalisation within the first 3 months after transcatheter aortic valve implantation (TAVI).

Methods

An international, multi-centre, prospective registry (CGA-TAVI) was established to gather data on CGA results and medium-term outcomes in geriatric patients undergoing TAVI. Logistic regression was used to evaluate the predictive value of a multidimensional prognostic index (MPI); a short physical performance battery (SPPB); and the Silver Code, which was based on administrative data, for predicting death and/or hospitalisation in the first 3 months after TAVI (primary endpoint).

Results

A total of 71 TAVI patients (mean age 85.4 years; mean log EuroSCORE I 22.5%) were enrolled. Device success according to VARC criteria was 100%. After adjustment for selected baseline characteristics, a higher (poorer) MPI score (OR: 3.34; 95% CI: 1.39–8.02; p = 0.0068) and a lower (poorer) SPPB score (OR: 1.15; 95% CI: 1.01–1.54; p = 0.0380) were found to be associated with an increased likelihood of the primary endpoint. The Silver Code did not show any predictive ability in this population.

Conclusions

Several aspects of the CGA have shown promise for being of use to physicians when predicting TAVI outcomes. While the MPI may be useful in clinical practice, the SPPB may be of particular value, being simple and quick to perform. Validation of these findings in a larger sample is warranted.

Trial registration

The trial was registered in ClinicalTrials.gov on November 7, 2013 (NCT01991444).

Model-Based Therapy Planning Allows Prediction of Haemodynamic Outcome after Aortic Valve Replacement

Optimizing treatment planning is essential for advances in patient care and outcomes. Precisely tailored therapy for each patient remains a yearned-for goal. Cardiovascular modelling has the potential to simulate and predict the functional response before the actual intervention is performed. The objective of this study was to proof the validity of model-based prediction of haemodynamic outcome after aortic valve replacement. In a prospective study design virtual (model-based) treatment of the valve and the surrounding vasculature were performed alongside the actual surgical procedure (control group). The resulting predictions of anatomic and haemodynamic outcome based on information from magnetic resonance imaging before the procedure were compared to post-operative imaging assessment of the surgical control group in ten patients. Predicted vs. post-operative peak velocities across the valve were comparable (2.97 ± 1.12 vs. 2.68 ± 0.67 m/s; p = 0.362). In wall shear stress (17.3 ± 12.3 Pa vs. 16.7 ± 16.84 Pa; p = 0.803) and secondary flow degree (0.44 ± 0.32 vs. 0.49 ± 0.23; p = 0.277) significant linear correlations (p < 0.001) were found between predicted and post-operative outcomes. Between groups blood flow patterns showed good agreement (helicity p = 0.852, vorticity p = 0.185, eccentricity p = 0.333). Model-based therapy planning is able to accurately predict post-operative haemodynamics after aortic valve replacement. These validated virtual treatment procedures open up promising opportunities for individually targeted interventions.

Assessment of aortic valve disease - a clinician oriented review

Aortic valve disease [aortic stenosis (AS) and aortic regurgitation (AR)] represents an important global health problem; when severe, aortic valve disease carries poor prognosis. For AS, aortic valve replacement, either surgical or interventional, may provide definite treatment in carefully selected patients. For AR, valve surgery (either replacement or - in selected cases - aortic valve repair) remains the gold standard of care. To properly identify those patients who are candidates for surgery, the clinician has to carefully assess the severity of valve disease with an understanding of the potential pitfalls involved in these assessments. This review focuses on the practical issues concerning the evaluation of patients with AS and AR from a general cardiologist’s perspective. The most important issues regarding the documentation of the severity of AS and AR are summarized. More specific issues, such as the role of stress echocardiography, other imaging techniques and details regarding the treatment options (medical, surgical, or interventional), are mentioned briefly.

Aortic Stenosis: Pathophysiology, Diagnosis, and Therapy

The incidence of aortic stenosis increases with age, affecting up to 10% of the population by the eighth decade. Once symptoms develop, aortic stenosis is rapidly fatal. Proper management requires an understanding of the physiology and criteria used to define disease severity. There is no effective pharmacologic treatment. Surgical aortic valve replacement has been the gold standard treatment for decades. However, over the last 10 years transcatheter aortic valve replacement has emerged as an attractive, less-invasive option for appropriately selected patients. Refinements in valve design and delivery systems have led to widespread use of this breakthrough technology in selected patients. We review the pathophysiology, criteria for valve replacement, and the results of the trials comparing transcatheter aortic valve replacement with surgical aortic valve replacement.

A hospital-based survey of patients with severe valvular heart disease in China

OBJECTIVES

Due to increasing aging, the epidemiology of VHD may have changed in China. This study aimed to provide contemporary information on the prevalence, distribution patterns, and etiology of severe VHD in China.

METHODS

This was a retrospective survey at Second Affiliated Hospital of Zhejiang University, which included all consecutive patients between 2010 and 2015.

RESULTS

In all, 139,496 patients were enrolled. Among severe valve diseases, MR was the most frequent (n=946, 0.68%) followed by MS (n=524, 0.38%), AS (n=392, 0.28%), and AR (n=371, 0.27%). Severe MR and AS prevalence rates increased strikingly with age. Rheumatic heart disease had an prevalence of 1.56% (n=2179), and remained one of the most common causes of severe VHD in patients younger than 65years old (99.5% of MS with rheumatic; 27.6% of MR with rheumatic; 25.7% of AS with rheumatic; 31.6% of AR with rheumatic). Aortic valve calcification was the predominant AS etiology, and its prevalence greatly increased with age. In severe AR, rheumatic fever was the most common etiology in patients below 65; in those above 65, etiology was mostly degenerative. In severe primary MR, mitral valve prolapse was the most common cause. Prevalence of secondary MR increased with age, from 16.4% in 18-44years old to 51.7% in individuals ≥75.

CONCLUSIONS

Severe valvular diseases are very common; rheumatic fever and degenerative valvular changes remain predominant causes in patients below 65 and older ones, respectively. Young adults present mainly with primary MR, while secondary MR is more common in elderly ones.

Morphology, Clinicopathologic Correlations, and Mechanisms in Heart Valve Health and Disease

The clinical and pathological features of the most frequent intrinsic structural diseases that affect the heart valves are well established, but heart valve disease mechanisms are poorly understood, and effective treatment options are evolving. Major advances in the understanding of the structure, function and biology of native valves and the pathobiology, biomaterials and biomedical engineering, and the clinical management of valvular heart disease have occurred over the past several decades. This communication reviews contemporary considerations relative to the pathology of valvular heart disease, including (1) clinical significance and epidemiology of valvular heart disease; (2) functional and dynamic valvular macro-, micro- and ultrastructure; (3) causes, morphology and mechanisms of human valvular heart disease; and (4) pathologic considerations in valve replacement, repair and, potentially, regeneration of the heart valves.