Aortic stenosis: medical and surgical management

Cerebral Embolic Protection Devices for Transcatheter Aortic Valve Replacement: Review of the Literature and Future Perspectives

PURPOSE OF REVIEW

Transcatheter aortic valve replacement (TAVR) has been a revolutionary therapy in the treatment of aortic valve stenosis. The risk of stroke associated with TAVR has decreased significantly since its introduction; however, it remains a devastating complication when it does occur.

RECENT FINDINGS

Many of the strokes associated with TAVR occur peri-procedurally and are thought to be due to embolic debris entering the cerebrovascular circulation. A number of different cerebral embolic protection devices (CEPD) have been developed and are in various stages of testing and use. The results from clinical trials evaluating the role for CEPD to reduce the risk of stroke have been mixed. As a result, their uptake has been very heterogeneous. This review provides a summary of the diverse CEPD devices available for use and outlines the clinical evidence available to date.

Inhibition of miR-101-3p prevents human aortic valve interstitial cell calcification through regulation of CDH11/SOX9 expression

BACKGROUND

Calcific aortic valve disease (CAVD) is the second leading cause of adult heart diseases. The purpose of this study is to investigate whether miR-101-3p plays a role in the human aortic valve interstitial cells (HAVICs) calcification and the underlying mechanisms.

METHODS

Small RNA deep sequencing and qPCR analysis were used to determine changes in microRNA expression in calcified human aortic valves.

RESULTS

The data showed that miR-101-3p levels were increased in the calcified human aortic valves. Using cultured primary HAVICs, we demonstrated that the miR-101-3p mimic promoted calcification and upregulated the osteogenesis pathway, while anti-miR-101-3p inhibited osteogenic differentiation and prevented calcification in HAVICs treated with the osteogenic conditioned medium. Mechanistically, miR-101-3p directly targeted cadherin-11 (CDH11) and Sry-related high-mobility-group box 9 (SOX9), key factors in the regulation of chondrogenesis and osteogenesis. Both CDH11 and SOX9 expressions were downregulated in the calcified human HAVICs. Inhibition of miR-101-3p restored expression of CDH11, SOX9 and ASPN and prevented osteogenesis in HAVICs under the calcific condition.

CONCLUSION

miR-101-3p plays an important role in HAVIC calcification through regulation of CDH11/SOX9 expression. The finding is important as it reveals that miR-1013p may be a potential therapeutic target for calcific aortic valve disease.

The application of 3D printing in preoperative planning for transcatheter aortic valve replacement: a systematic review

BACKGROUND

Recently, transcatheter aortic valve replacement (TAVR) has been suggested as a less invasive treatment compared to surgical aortic valve replacement, for patients with severe aortic stenosis. Despite the attention, persisting evidence suggests that several procedural complications are more prevalent with the transcatheter approach. Consequently, a systematic review was undertaken to evaluate the application of three-dimensional (3D) printing in preoperative planning for TAVR, as a means of predicting and subsequently, reducing the incidence of adverse events.

METHODS

MEDLINE, Web of Science and Embase were searched to identify studies that utilised patient-specific 3D printed models to predict or mitigate the risk of procedural complications.

RESULTS

13 of 219 papers met the inclusion criteria of this review. The eligible studies have shown that 3D printing has most commonly been used to predict the occurrence and severity of paravalvular regurgitation, with relatively high accuracy. Studies have also explored the usefulness of 3D printed anatomical models in reducing the incidence of coronary artery obstruction, new-onset conduction disturbance and aortic annular rapture.

CONCLUSION

Patient-specific 3D models can be used in pre-procedural planning for challenging cases, to help deliver personalised treatment. However, the application of 3D printing is not recommended for routine clinical practice, due to practicality issues.

Cellular senescence evaluated by P16INK4a immunohistochemistry is a prevalent phenomenon in advanced calcific aortic valve disease

BACKGROUND

Fibrosis, calcification, and ossification are histopathologic hallmarks of calcific aortic valve disease (CAVD), a leading cause of morbidity and mortality in the aging population. Cellular senescence contributes to a functional decay in chronic diseases by intensifying tissue remodeling and impairing tissue regeneration. We evaluated the expression of P16^INK4A and P53 as surrogate markers of senescence in CAVD.

METHODS

Aortic valves from 27 individuals with severe CAVD requiring aortic valve replacement were selected for routine histologic processing. Immunohistochemical expression of P16^INK4A and P53 was quantified using computerized image analysis on fields matching compartments with varying degrees of tissue remodeling.

RESULTS

All aortic valves demonstrated P16^INK4A and P53-positive cells. The percentage of P16^INK4A -positive cells, but not of P53, was higher in areas of calcification and/or ossification (57.21%±26.31, n=40) and severe fibrosis (54.79%±27.19, n=25) than in areas with minimal to mild tissue remodeling (13.69% ± 11.88, n=16, P<.0001). P16^INK4A expression was observed in interstitial valve cells within all compartments proportional to the degree of fibrosis and did not correlate with age, severity of aortic stenosis, or P53 expression. Multiple linear regression analysis by backward elimination revealed P16^INK4A expression was lower among statin users (P<.01).

CONCLUSIONS

P16^INK4A- expression is ubiquitous in calcified aortic valves and correlates with severity of tissue remodeling, suggesting a role of cellular senescence in the progression of CAVD. Further research is needed to identify possible treatment modalities as disease modifying agents for CAVD.

Transcatheter aortic valve replacement in patients with a history of cancer: Periprocedural and long-term outcomes

BACKGROUND

A history of cancer is incorporated into the surgical risk assessment of patients undergoing surgical aortic valve replacement through the Society for Thoracic Surgeons score. However, the prognostic significance of cancer in patients treated with transcatheter aortic valve replacement (TAVR) is unclear. As the cancer survivorship population increases, it is imperative to establish the efficacy and safety of TAVR in patients with severe symptomatic aortic stenosis (AS) and a history of malignancy.

OBJECTIVES

The primary goal of this study was to assess the periprocedural outcomes and long-term mortality in patients with a history of cancer undergoing TAVR.

METHODS

A systematic review of PubMed, MEDLINE, and EMBASE was conducted to identify studies reporting outcomes in patients with a history of malignancy undergoing TAVR. A meta-analysis was performed using a random-effects model with a primary outcome of all-cause mortality and cardiac mortality at the longest follow-up. On secondary analyses, procedural safety was assessed.

RESULTS

A total of 13 observational studies with 10,916 patients were identified in the systematic review. Seven studies including 6,323 patients were included in the quantitative analysis. Short-term mortality (relative risk [RR] 0.61, 95%CI 0.36-1.01; p = .06) and long-term all-cause mortality (RR 1.24, 95%CI 0.95-1.63; p = .11) were not significantly different when comparing patients with and without a history of cancer. No significant difference in the rate of periprocedural complications including stroke, bleeding, acute kidney injury, and pacemaker implantation was noted.

CONCLUSION

In patients with severe AS undergoing TAVR, a history of cancer was not associated with adverse short or long-term survival. Based on these findings, TAVR should be considered in all patients with severe symptomatic AS, irrespective of their history of malignancy.

Quantification of aortic valve area: comparison of different methods of echocardiography with 3-D scan of the excised valve

Accurate determination of severity of aortic valve stenosis (AS) by aortic valve area (AVA) is essential for choosing the best treatment strategy. We compared AVA quantified by 4 different in vivo echocardiographic methods with AVA measured by 3D ex vivo scanning of the excised AV. The data on 38 patients who underwent aortic valve replacement were assessed. The AVA was determined by 4 echocardiographic methods of planimetry in 2D transesophageal echocardiography [planimetry (2D-TEE)], plainemetry by multiplanar reconstruction approach in 3D transesophageal echocardiography [MPR (3D-TEE)], and two continuity equation (CE) approaches; conventional CE (2D-TTE) in which left ventricular outflow tract [LVOT] area derived by LVOT diameter obtained in 2D transthoracic echocardiography and CE (3D-TEE) in which LVOT area obtained by 3D MPR. After the surgical removal of the AV, AVA was determined by 3D ex vivo scanning. Lowest AVA mean difference with 3D ex vivo scanning was found between CE (2D-TTE), followed by CE (3D-TEE). Planimetry (2D-TEE) in male patients as well as severely and non-severely calcified valves revealed a significant higher AVA mean difference with 3D ex vivo scanning than CE (2D-TTE) and CE (3D-TEE) methods. However, with a nonsignificant effect, CE (2D-TTE) and planimetry (2D-TEE) had the least mean difference with 3D ex vivo scanning possibly due to less frequent bicuspid AV in females. CE (2D-TTE) was more accurate than other methods of AVA calculation. Moreover, CE (3D-TEE) and MPR (3D-TEE) methods had acceptable accuracy in comparison with planimetry (2D-TEE) for definition of AS severity.

Novel Perspective for Antithrombotic Therapy in TAVI

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While surgical aortic valve replacement (SAVR) was for years the only available treatment for symptomatic aortic stenosis, the introduction of transcatheter aortic valve implantation (TAVI) in 2002 and the improvement of its technical aspects in the following years, has holistically changed the synchronous therapeutic approach of aortic valve stenosis. Recent evidence has expanded the indication of TAVI from high to lower surgical risk populations with symptomatic aortic stenosis. The administration of antithrombotic therapy periprocedurally and its maintenance after a successful TAVI is crucial for the prevention of complications and affects postprocedural survival. Randomized controlled trials investigating the appropriate combination and the duration of antithrombotic treatment after TAVI are for the moment scarce. This review article sheds light on the underlying pathogenetic mechanisms contributing in periprocedural TAVI thrombotic complications and discuss the efficacy of current antithrombotic policies as evaluated in randomized trials.

Transcatheter Aortic Valve Replacement versus Surgical Aortic Valve Replacement: A Review of Aortic Stenosis Management

Severe aortic stenosis (AS) affects 3.4% of the elderly over 60 years of age. It presents with exertional dyspnea, syncope, angina, and progression to irreversible congestive heart failure. Early intervention produces a better outcome in preventing the clinical deterioration of AS. The choice of intervention is transcatheter aortic valve implantation or surgical aortic valve replacement (SAVR). The decision should be made after evaluating an individual case based on its clinical features and the user’s experience with transcatheter aortic valve replacement (TAVR). We reviewed available data to illustrate the types of ASs, the background of interventions, current guidelines for TAVR, and its comparison with SAVR in terms of adverse effects.

Nt-ProBNP Discriminatory Role Between Symptomatic and Asymptomatic Patients with Severe Valvular Aortic Stenosis

Background: The aim was to evaluate the Nt-proBNP discriminatory role between symptomatic and asymptomatic patients with severe aortic stenosis.

Methods: 187 patients with severe valvular aortic stenosis, with normal EF > 50%, were included, 61 asymptomatic and 126 symptomatic. We used clinical, laboratory (Nt-proBNP) and echocardiographic parameters. Endpoints of monitoring (occurrence of event) were: the onset of symptoms in asymptomatic patients and death in both groups.

Results: The symptomatic group with severe AS had a significantly higher means of Nt-proBNP, in comparison with the asymptomatic group. Nt-proBNP was a significant predictor for the risk of event occurrence (HR 1.4). In the group of severe AS without CAD (n = 101), the subgroup with Nt-proBNP above the cut-off value, took significantly higher percentage of patients with chest pain, fatigue and syncope. In the group with Nt-proBNP above the cut-off value, we had a significantly higher percentage of patients with severe AS without CAD, compared to those with CAD (n = 142). Nt-proBNP was negatively correlated with AVA and LVEF, whether the positive correlation was expressed for: LVEDd, LVEDs, IVSd, AV_Vmax, AV_MaxGrad, LVM and LA. Patients with Nt-proBNP above the cut-off, had a significantly lower event free survival, compared to patients with Nt-proBNP below the cut-off (n = 187; n = 101).

Conclusion: The Nt-proBNP cut-off> 460 pg/ml was confirmed as a useful tool in the determination of event free survival in patients with severe AS. Nt-proBNP not only had relevance in the assessment of the severity of the disease, but also was a significant predictor for the risk of event occurrence.

Value of neutrophil to lymphocyte ratio as a predictor of mortality in patients undergoing aortic valve replacement

Background

Neutrophil to lymphocyte ratio (NLR) has been studied as a measure of inflammation and as a prognosticating factor in various medical conditions including neoplastic, inflammatory and cardiovascular. The prognostic role of NLR in predicting mortality in patients with aortic stenosis undergoing surgical aortic valve replacement (AVR) has not been studied. The aim of our study is to explore the utility of NLR as a predictor of both, short and long-term mortality, in patients undergoing surgical AVR.

Methods

Consecutive patients with aortic stenosis admitted for AVR to our institution were evaluated for study inclusion. Of the 335 patients admitted from January 2007 to September 2011, 234 met study inclusion criteria. Patients were divided into two groups depending on their initial preoperative NLR level with a cutoff value of 3. Three-year vital status was accessed with electronic medical records and Social Security Death Index. Survival analysis, stratified by NLR, was used to evaluate the predictive value of preoperative NLR levels.

Results

Patients with NLR ≥3, when compared to those with NLR <3, had a significantly higher short-term (9.40% vs. 0, P=0.0006), 6-month (19.54% vs. 0.95%, P<0.0001), and 3-year mortality (27.35% vs. 3.78%, P<0.0001). After adjustment for baseline characteristics, co-morbidities, symptomatology, echocardiographic findings, and blood tests, NLR level remained a significant independent predictor of 3-year mortality; Hazard ratios (HRs) increased by a factor of 1.18 (1.05-1.33, P=0.0068) and patients with a NLR ≥3 had 4.77 fold increase in 3-year mortality (1.48-15.32, P=0.0090).

Conclusions

NLR is an independent predictor of short-term and long-term mortality in patients with aortic stenosis undergoing AVR surgery, especially those with NLR ≥3. We strongly suggest the use of NLR as a tool to risk stratify patients with aortic stenosis undergoing AVR surgery.

Secreted Klotho Attenuates Inflammation-Associated Aortic Valve Fibrosis in Senescence-Accelerated Mice P1

Senescence-accelerated mice P1 (SAMP1) is an aging model characterized by shortened lifespan and early signs of senescence. Klotho is an aging-suppressor gene. The purpose of this study is to investigate whether in vivo expression of secreted klotho (Skl) gene attenuates aortic valve fibrosis in SAMP1 mice. SAMP1 mice and age-matched (AKR/J) control mice were used. SAMP1 mice developed obvious fibrosis in aortic valves, namely fibrotic aortic valve disease. Serum level of Skl was decreased drastically in SAMP1 mice. Expression of MCP-1 (monocyte chemoattractant protein 1), ICAM-1 (intercellular adhesion molecule 1), F4/80, and CD68 was increased in aortic valves of SAMP1 mice, indicating inflammation. An increase in expression of α-smooth muscle actin (myofibroblast marker), transforming growth factorβ-1, and scleraxis (a transcription factor of collagen synthesis) was also found in aortic valves of SAMP1 mice, suggesting that accelerated aging is associated with myofibroblast transition and collagen gene activation. We constructed adeno-associated virus 2 carrying mouse Skl cDNA for in vivo expression of Skl. Skl gene delivery effectively increased serum Skl of SAMP1 mice to the control level. Skl gene delivery inhibited inflammation and myofibroblastic transition in aortic valves and attenuated fibrotic aortic valve disease in SAMP1 mice. It is concluded that senescence-related fibrotic aortic valve disease in SAMP1 mice is associated with a decrease in serum klotho leading to inflammation, including macrophage infiltration and transforming growth factorβ-1/scleraxis-driven myofibroblast differentiation in aortic valves. Restoration of serum Skl levels by adeno-associated virus 2 carrying mouse Skl cDNA effectively suppresses inflammation and myofibroblastic transition and attenuates aortic valve fibrosis. Skl may be a potential therapeutic target for fibrotic aortic valve disease.

Statins and Progression of Calcified Aortic Stenosis

Objective:

To review the evidence evaluating the efficacy of statins in reducing the progression of calcified aortic stenosis (AS).

Data Sources:

MEDLINE, EMBASE, and PubMed were searched (all up to November 2006) for studies evaluating the use of statins to reduce the progression of calcified AS. Search terms included statin, HMG CoA reductase inhibitor, calcified AS, valve stenosis, and calcified stenosis. Additional primary trials were located by searching references noted in review articles.

Study Selection and Data Extraction:

Clinical trials published in the English language were selected for review. Primary efficacy outcomes evaluated were changes in aortic valve measurements, hemodynamic measures of AS, and change in measures of AS severity.

Data Synthesis:

TWO prospective clinical trials and 5 retrospective studies were included in this review. All of the retrospective studies demonstrated that statin use was associated with a statistically significant delay in the progression of AS. One prospective observation trial showed benefit of statin use; however, a large, randomized, double-blind, prospective trial showed no benefit of statin use in decreasing the progression of AS.

Conclusions:

An association between statin use and a delay in AS progression has been observed in retrospective studies; however, prospective trials showed conflicting results. Currently, statins cannot be recommended for medical treatment of AS until larger trials are conducted.

Mean Transaortic Gradient is an Emerging Predictor of Chronic Kidney Disease in Elderly Patients

Arterial hypertension (AH) is a major risk factor for chronic kidney disease (CKD). However, whether AH maintains this role in the development of CKD in elderly patients with aortic stenosis (AS) or whether transaortic gradient influences CKD remains unclear. Consecutive hospitalized patients were prospectively recruited to evaluate the relationship between AS and CKD. In all patients, transthoracic 2-dimensional echocardiography was performed to evaluate AS; renal function was evaluated using the Chronic Kidney Disease Epidemiology Collaboration formula. A total of 346 patients were included in the study (mean age: 79.5 ± 7.4 years): 104 had diabetes mellitus (DM), 298 had AH, and 59 (moderate: 52; severe: 7) showed AS. After multivariate analysis, age ( P <.01), DM ( P = .02), and mean transaortic gradient ( P = .03), but not AH, were independent predictors of CKD. Both in the presence (n = 59) or absence (n = 287) of AS, the estimated glomerular filtration rate did not differ in patients with (51 ± 24 mL/min/1.73 m2 and 59 ± 25 mL/min/1.73 m2, respectively) and those without AH (50 ± 21 mL/min/1.73 m2 and 65 ± 24 mL/min/1.73 m2, respectively). In the whole population, for each mm Hg of mean transaortic gradient, the risk of CKD increased by 2.5 times.

Deficiency in the anti-aging gene Klotho promotes aortic valve fibrosis through AMPKα-mediated activation of RUNX2

Fibrotic aortic valve disease (FAVD) is an important cause of aortic stenosis, yet currently there is no effective treatment for FAVD due to its unknown etiology. The purpose of this study was to investigate whether deficiency in the anti‐aging Klotho gene (KL) promotes high‐fat‐diet‐induced FAVD and to explore the underlying molecular mechanism. Heterozygous Klotho‐deficient (KL^+/−) mice and WT littermates were fed with a high‐fat diet (HFD) or normal diet for 13 weeks, followed by treatment with the AMPKα activator (AICAR) for an additional 2 weeks. A HFD caused a greater increase in collagen levels in the aortic valves of KL^+/− mice than of WT mice, indicating that Klotho deficiency promotes HFD‐induced aortic valve fibrosis (AVF). AMPKα activity (pAMPKα) was decreased, while protein expression of collagen I and RUNX2 was increased in the aortic valves of KL^+/− mice fed with a HFD. Treatment with AICAR markedly attenuated HFD‐induced AVF in KL^+/− mice. AICAR not only abolished the downregulation of pAMPKα but also eliminated the upregulation of collagen I and RUNX2 in the aortic valves of KL^+/− mice fed with HFD. In cultured porcine aortic valve interstitial cells, Klotho‐deficient serum plus cholesterol increased RUNX2 and collagen I protein expression, which were attenuated by activation of AMPKα by AICAR. Interestingly, silencing of RUNX2 abolished the stimulatory effect of Klotho deficiency on cholesterol‐induced upregulation of matrix proteins, including collagen I and osteocalcin. In conclusion, Klotho gene deficiency promotes HFD‐induced fibrosis in aortic valves, likely through the AMPKα–RUNX2 pathway.

Transcatheter aortic valve implantation versus surgical aortic valve replacement: A meta-analysis of randomized controlled trials

BACKGROUND

Transcatheter aortic valve implantation (TAVI) has become a widely utilized method of treatment of severe aortic valve stenosis. The present meta-analysis included all published relevant randomized controlled trials (RCTs) and aimed to compare the safety and efficacy of TAVI compared to surgical aortic valve replacement (AVR).

METHOD

Nine electronic databases were comprehensively searched. Eligible studies were required to be randomized controlled trials which reported comparative endpoints on both TAVI and AVR.

RESULTS

Five published RCTs were included in the meta-analysis. A total of 3828 patients were studied. The overall mortality and stroke rates at 30days and 1year were not significantly different between TAVI and AVR. Patients undergoing TAVI were more likely to experience vascular complications, aortic regurgitation and permanent pacemaker insertion, however, they were less likely to encounter acute renal failure and major haemorrhage.

CONCLUSIONS

The data suggest that TAVI is a safe and efficacious alternative to surgical aortic valve replacement in judiciously selected patients.

Asymptomatic severe aortic stenosis with normal left ventricular function - A review

Aortic stenosis (AS) is one of the commonest forms of acquired valvular heart disease. Aortic valve replacement (AVR) is the treatment of choice for symptomatic severe AS. Conservative management is usually advocated for asymptomatic severe AS. But there are data on predictors to identify subsets of asymptomatic AS patients at high risk of cardiac events in whom early surgical intervention is warranted. Non-invasive tests like exercise stress test, exercise echocardiography will help us to identify those who are at high risk of developing early symptoms due to LV dysfunction and also those at high risk of sudden death. In this article, an attempt is made to review the literature on this subset of asymptomatic severe AS to help clinicians to decide regarding the need for early aortic valve replacement in them.

The Early Variation of Left Ventricular Strain after Aortic Valve Replacement by Three-Dimensional Echocardiography

Aortic stenosis (AS) and aortic incompetence (AI) are common aortic valve diseases. Both may deteriorate into irreversible myocardial dysfunction and will increase the risk of sudden death. In this study, we aimed to investigate the early variation trend of left ventricular function by three-dimensional speckle tracking echocardiography (3D-STE) in the patients who underwent cardiac surgeries for aortic valve disease. Twenty patients with severe aortic AS and 16 patients with severe AI were enrolled. All of them underwent the aortic valve replacement (AVR) procedures. The patients’ global longitudinal strain (GLS) and global circumferential strain (GCS) were evaluated by 3D-STE before surgery and at 1 week after surgery. In addition, GLS and GCS were followed at 1 month as well as 3 months after AVR. In AS patients, the GCS after AVR altered little both at 1 week (p = 0.562) and at 1 month (p = 0.953) compared with the data before the surgery. And it increased significantly at 3 months of follow-up observation compared to that before AVR (p<0.05). Meanwhile, GLS increased progressively after AVR and improved significantly at 3 months after surgery (p<0.05). For the AI patients, GLS as well as GCS decreased at 1 week after AVR compared to those data at baseline (p<0.05). However, these two parameters recovered at 1 month after AVR. Furthermore, GLS and GCS improved significantly at 3 months after the surgery (p<0.05). Therefore, both GLS and GCS were influenced by AVR and would be improved at 3 months after surgery both in AS patients or AI patients. GLS and GCS can be finely evaluated by 3D-STE, and they are helpful to determine the variation tendency of left ventricular function in patients with AVR.

Cardiovascular magnetic resonance assessment of the aortic valve stenosis: an in vivo and ex vivo study

Background

Aortic valve area (AVA) estimation in patients with aortic stenosis may be obtained using several methods. This study was undertaken to verify the cardiovascular magnetic resonance (CMR) planimetry of aortic stenosis by comparing the findings with invasive catheterization, transthoracic (TTE) as well as tranesophageal echocardiography (TEE) and anatomic CMR examination of autopsy specimens.

Methods

Our study was performed in eight patients with aortic valve stenosis. Aortic stenosis was determined by TTE and TEE as well as catheterization and CMR. Especially, after aortic valve replacement, the explanted aortic valves were examined again with CMR ex vivo model.

Results

The mean AVA determined in vivo by CMR was 0.75 ± 0.09 cm² and ex vivo by CMR was 0.65 ± 0.09 cm² and was closely correlated (r = 0.91, p < 0.001). The mean absolute difference between AVA derived by CMR ex vivo and in vivo was −0.10 ± 0.04 cm². The mean AVA using TTE was 0.69 ± 0.07 with a significant correlation between CMR ex vivo (r = 0.85, p < 0.007) and CMR in vivo (r = 0.86, p < 0.008). CMR ex vivo and in vivo had no significant correlation with AVA using Gorlin formula by invasive catheterization or using planimetry by TEE.

Conclusion

In this small study using an ex vivo aortic valve stenosis model, the aortic valve area can be reliably planimetered by CMR in vivo and ex vivo with a well correlation between geometric AVA by CMR and the effective AVA calculated by TTE.

Platelet activation and arterial peripheral serotonin turnover in cardiac remodeling associated to aortic stenosis

Peripheral serotonin (5-HT) has been involved in adverse cardiac remodeling and valve fibrosis. The peripheral levels of 5-HT mainly depend on its release from activated platelets and degradation by monoamine oxidase A (MAO-A). The SERAOPI study investigated the relationship between arterial serotoninergic system, degree of platelet activation and cardiac remodeling, in patients with aortic valve stenosis (AS). Thirty patients with severe AS and 15 control subjects underwent transthoracic echocardiography, radial, and aortic arterial blood sampling. Measurements of 5-HT and its MAO-A-dependent degradation product, 5-HIAA, were performed by HPLC. Arterial platelet activation was assessed by flow cytometry analysis of platelet surface expression of P-selectin and activated integrin GPIIb/IIIa. Activated platelets and arterial plasma 5-HT increased in AS patients as compared to control subjects (P-selectin 1.08 ± 0.2MFI vs. 0.49 ± 0.1MFI, P = 0.04; GPIIb/IIIa 0.71 ± 0.1MFI vs. 0.35 ± 0.1MFI; P = 0.0015 and arterial plasma 5-HT 11.55 ± 1.6 nM vs. 6.18 ± 0.7 nM, P = 0.028, respectively). Moreover, 5-HT was strongly correlated to left ventricular hypertrophy assessed by echocardiography. The correlation was independent of cardiovascular risk comorbidities and others echocardiographic AS parameters. Finally, plasma 5-HIAA increased in AS patients (74.64 ± 9.7 nM vs. 37.16 ± 4.1 nM; P = 0.0002) indicating a higher 5-HT degradation rate by MAO-A. Platelet activation, arterial circulating serotonin, and serotonin degradation increased in patients with AS. These observations suggest that the serotoninergic system may contribute to the pathogenesis of AS including valve fibrosis and adverse ventricular remodeling.

Is the degeneration of aortic valve bioprostheses similar to that of native aortic valves? Insights into valvular pathology

Aortic stenosis (AS) is the most common valvular disease requiring valve replacement with a prevalence of 2-4% in adults greater than or equal to 65 years of age. There is increasing evidence that AS is an active inflammatory process that is highly regulated, displaying multiple hallmarks of atherosclerosis. Clinically, the definite therapy of advanced AS is prosthetic valve replacement. Herein, bioprosthetic tissue valves (BPs) possess superior thromboresistant and hemodynamic properties compared with mechanical valves. However, cusp degeneration and calcification also limit their long-term outcome. The pathogenesis of BP calcification as well as that of native valves is still poorly understood. Recent studies suggest a similar valvular pathology, that underlies both types of valvular degeneration, but also an even more important role of inflammatory and repair processes in the case of BP degeneration.

Fibrocalcific aortic valve disease: opportunity to understand disease mechanisms using mouse models

Studies in vitro and in vivo continue to identify complex-regulated mechanisms leading to overt fibrocalcific aortic valve disease (FCAVD). Assessment of the functional impact of those processes requires careful studies of models of FCAVD in vivo. Although the genetic basis for FCAVD is unknown for most patients with FCAVD, several disease-associated genes have been identified in humans and mice. Some gene products which regulate valve development in utero also protect against fibrocalcific disease during postnatal aging. Valve calcification can occur via processes that resemble bone formation. But valve calcification can also occur by nonosteogenic mechanisms, such as formation of calcific apoptotic nodules. Anticalcific interventions might preferentially target either osteogenic or nonosteogenic calcification. Although FCAVD and atherosclerosis share several risk factors and mechanisms, there are fundamental differences between arteries and the aortic valve, with respect to disease mechanisms and responses to therapeutic interventions. Both innate and acquired immunity are likely to contribute to FCAVD. Angiogenesis is a feature of inflammation, but may also contribute independently to progression of FCAVD, possibly by actions of pericytes that are associated with new blood vessels. Several therapeutic interventions seem to be effective in attenuating the development of FCAVD in mice. Therapies which are effective early in the course of FCAVD, however, are not necessarily effective in established disease.

Association of myocardial deformation with outcome in asymptomatic aortic stenosis with normal ejection fraction

BACKGROUND

Current guidelines recommend intervention for symptomatic aortic stenosis, but the management of asymptomatic aortic stenosis remains controversial. As left ventricular global longitudinal strain (GLS) has been shown to predict cardiovascular outcome, we sought to find whether its use could guide the assessment of risk in these patients.

METHODS AND RESULTS

We prospectively followed 79 patients with severe asymptomatic aortic stenosis (39 men; mean age, 77 ± 12 years; aortic valve [AV] area index, 0.36 cm(2)/m(2)). In addition to standard echocardiography, speckle strain was measured to assess GLS. Patients were followed for cardiac death and AV replacement driven by symptom development. A multivariable Cox regression was performed to identify associations with events. During 23 ± 20 months, 3 patients had cardiac death and 49 underwent AV replacement. Event-free survival was 72 ± 5% at 1 year, 50 ± 5% at 2 years, and 24 ± 5% at 4 years. Death and AV replacement were predicted by GLS (hazard ratio [HR], 1.14 [95% CI, 1.01-1.28]; P=0.037), as well as extent of AV calcification (HR, 2.44 [95% CI, 1.17-5.12]; P=0.018), peak transaortic pressure gradient (HR, 1.03 [95% CI, 1.01-1.04]; P<0.001), valvulo-arterial impedance (HR, 1.32 [95% CI, 1.04-1.67]; P=0.045), and Society of Thoracic Surgeons Predicted Risk of Morbidity and Mortality (HR, 0.95 [95% CI, 0.90-1.00]; P=0.052). A mean absolute GLS <15% was associated with a significant excess mortality, and this measurement added incremental prognostic value to the Society of Thoracic Surgeons Predicted Risk of Morbidity and Mortality, transaortic peak pressure gradient, AV calcification, and valvulo-arterial impedance.

CONCLUSIONS

GLS is associated with outcomes in patients with severe asymptomatic aortic stenosis, incremental to other clinical and echocardiographic variables.

Circulating endothelial progenitor cells in patients with dysfunctional versus normally functioning congenitally bicuspid aortic valves

Patients with bicuspid aortic valve (BAV) may gradually develop significant valve dysfunction, whereas others remain free of dysfunction. Factors that determine the prognosis of BAV remain unclear. Because endothelial progenitor cells (EPCs) have a role in the repair of endothelial surfaces after injury, we hypothesized that EPCs may also be involved in preventing BAV degeneration. Accordingly, we compared EPC level and function in patients with BAV with versus without valve dysfunction. The study group included 22 patients with BAV and significant valve dysfunction (at least moderate aortic regurgitation and/or at least moderate aortic stenosis). The control group included 28 patients with BAV without valve dysfunction. All patients had 1 blood sample taken. Proportion of peripheral mononuclear cells expressing vascular endothelial growth factor receptor 2, CD133 and CD34 was evaluated by flow cytometry. EPC colony-forming units (CFUs) were grown from peripheral mononuclear cells, characterized, and counted after 7 days of culture. The 2 groups had similar clinical characteristics except for higher prevalence of hypertension in the dysfunctional valve group. Number of EPC CFUs was smaller in the dysfunctional valve group (32 CFUs/plate, 15 to 42.5, vs 48 CFUs/plate, 30 to 62.5, respectively, p = 0.01), and the migratory capacity of the cells in this group was decreased. In addition, the proportion of cells coexpressing vascular endothelial growth factor receptor 2, CD133, and CD34 tended to be smaller in the dysfunctional valve group. In conclusion, patients with BAV and significant valve dysfunction appear to have circulating EPCs with impaired functional properties. These findings require validation by further studies.

Management and outcomes of severe aortic stenosis in cancer patients

BACKGROUND

Aortic stenosis (AS) is the commonest native valve lesion, affecting 43% of all patients with valvular heart disease. The optimal treatment of severe AS in cancer patients is unknown. The purpose of this study was to assess the impact of aortic valve replacement (AVR) on survival of cancer patients with severe AS.

METHODS

Cancer patients with severe AS seen at our center between January 2001 and April 2007 were identified. Baseline demographics, symptoms, cancer diagnosis, laboratory data, treatment, and outcome were collected. Patient who had AVR were matched with controls who did not have AS.

RESULTS

Out of 39,071 echocardiograms performed over the study period, 1,299 had AS (3.3%), of which 50 patients (0.13%) were identified as having severe AS. Thirteen patients (27%) underwent AVR, and 35 were managed medically. Two patients underwent valvuloplasty and were excluded. Survival was significantly longer in patients with severe AS who underwent AVR and was independent of cancer status or presence of metastases. No difference in survival was found between patients who underwent AVR and matched cancer controls. In a multivariable Cox proportional hazard regression analysis, AVR was the only significant predictor of longer survival (adjusted hazard ratio = 0.22, P = .028).

CONCLUSIONS

Cancer patients with severe AS who underwent AVR had an improved survival, regardless of cancer status.

Degenerative valve disease and bioprostheses: risk assessment, predictive diagnosis, personalised treatments

Aortic stenosis (AS) is the most frequent valvular heart disease. Severe AS results in concentric left ventricular hypertrophy, and ultimately, the heart dilates and fails. During a long period of time patients remain asymptomatic. In this period a pathology progression should be monitored and effectively thwarted by targeted measures. A cascade of cellular and molecular events leads to chronic degeneration of aortic valves. There are some molecular attributes characteristic for the process of valvular degeneration with clear functional link between shifted cell-cycle control, calcification and tissue remodelling of aortic valves. Bioactivity of implanted bioprosthesis is assumed to result in its dysfunction. Age, gender (females), smoking, Diabetes mellitus, and high cholesterol level dramatically shorten the re-operation time. Therefore, predictive and preventive measures would be highly beneficial, in particular for young female diabetes-predisposed patients. Molecular signature of valvular degeneration is reviewed here with emphases on clinical meaning, risk-assessment, predictive diagnosis, individualised treatments.

Screening and evaluation of the cardiovascular and pulmonary systems in patients presenting with upper extremity impairments

NARRATIVE REVIEW: Given the prevalence of cardiovascular and pulmonary (CV-P) disease, it is likely that a substantial portion of patients seeking services from hand therapists have diagnosed or yet to be diagnosed disease in one or both of these systems. Pain originating from these systems is more common in the chest, shoulder, and scapular regions, but both systems can refer pain into the medial aspect of the forearm and hand. Pancoast's tumors of the lung, myocardial ischemia, and myocardial infarction are examples of specific pathologies capable of referring pain into these upper extremity regions. Another concern for the hand therapist is that upper extremity exercise is more stressful on the cardiovascular system than lower extremity exercise. Because of this, hand therapists need to be able to recognize when to discontinue or modify exercise interventions based on inappropriate cardiovascular system responses. Thus, the purpose of this review is to present 1) screening for potential pathology in the CV-P systems, 2) methods typically available to hand therapists for monitoring these systems, 3) criteria that indicate the need for therapy modification or medical referral, and 4) symptomatology of some common cardiac and pulmonary pathologic conditions the hand therapist may encounter.

LEVEL OF EVIDENCE

5.

Valvular aortic stenosis: a proteomic insight

Calcified aortic valve disease is a slowly progressive disorder that ranges from mild valve thickening with no obstruction of blood flow, known as aortic sclerosis, to severe calcification with impaired leaflet motion or aortic stenosis. In the present work we describe a rapid, reproducible and effective method to carry out proteomic analysis of stenotic human valves by conventional 2-DE and 2D-DIGE, minimizing the interference due to high calcium concentrations. Furthermore, the protocol permits the aortic stenosis proteome to be analysed, advancing our knowledge in this area.

SUMMARY

Until recently, aortic stenosis (AS) was considered a passive process secondary to calcium deposition in the aortic valves. However, it has recently been highlighted that the risk factors associated with the development of calcified AS in the elderly are similar to those of coronary artery disease. Furthermore, degenerative AS shares histological characteristics with atherosclerotic plaques, leading to the suggestion that calcified aortic valve disease is a chronic inflammatory process similar to atherosclerosis. Nevertheless, certain data does not fit with this theory making it necessary to further study this pathology. The aim of this study is to develop an effective protein extraction protocol for aortic stenosis valves such that proteomic analyses can be performed on these structures. In the present work we have defined a rapid, reproducible and effective method to extract proteins and that is compatible with 2-DE, 2D-DIGE and MS techniques. Defining the protein profile of this tissue is an important and challenging task that will help to understand the mechanisms of physiological/pathological processes in aortic stenosis valves.

Left ventricular response to exercise in aortic stenosis: an exercise echocardiographic study

BACKGROUND

While normal at rest, left ventricular (LV) systolic function may become abnormal during exercise in patients with aortic stenosis. Once contraindicated in patients with aortic stenosis, exercise testing is now recommended in asymptomatic patients with aortic stenosis to elicit symptoms and thereby ascertain the need for aortic valve replacement. However, the clinical significance of an abnormal LV response to exercise in asymptomatic patients with aortic stenosis remains unknown.

OBJECTIVE

The aim of this study was to evaluate the clinical implications of an abnormal LV response during exercise in the setting of aortic stenosis.

METHODS

We monitored the LV response to exercise by 2D-Doppler echocardiography during a symptom limited semirecumbent bicycle exercise in 50 patients with tight aortic stenosis (aortic valve area < or = 1.0 cm(2)) and a normal LV systolic function (LV ejection fraction, EF > or = 50%) and followed them for an average of 11 months.

RESULTS

Twenty patients had an abnormal LV response to exercise with a mean decrease in LV EF from 64 +/- 10 to 53 +/- 12% while 30 patients had a normal LV response to exercise with a mean increase in LV EF from 62 +/- 7 to 70 +/- 8%. Patients with an abnormal LV response during exercise were more likely to develop symptoms during exercise than patients with a normal LV response: 80% versus 27% (P< 0.0001). The survival free of cardiac events was significantly lower in patients with abnormal LV response to exercise than in patients with a normal response (P = 0.03).

CONCLUSION

Exercise echocardiography provides objective data that facilitate interpretation of exercise elicited symptoms in asymptomatic patients with severe aortic stenosis. In addition, an abnormal LV response to exercise may predict a poor outcome.

Congenital aortic stenosis in adults: Rate of progression and predictors of clinical outcome

BACKGROUND

Little data are available on the natural history of young adults with congenital valvular aortic stenosis (AS). The aim of the present study was to determine the progression rate of AS in young adults, and to identify predictors of stenosis progression and outcome.

METHODS

Retrospective study of all patients seen at a single centre diagnosed with congenital AS (> or = 2.5 m/s) between 1992 and 2005, excluding patients with severe aortic regurgitation. The slope of the regression of the aortic jet velocity on the time elapsed since the baseline study was used to define the rate of progression of stenosis.

RESULTS

A total of 84 adults (mean age, 23.5+/-7.9 years) were studied who had at least two echocardiograms > 1 year (5.6+/-2.6 years) apart. The annual progression of aortic jet velocity was 0.09+/-0.15 m/s per year. Multivariable linear regression analysis identified older age (p<0.001) as an independent predictor of faster haemodynamic progression. During the follow-up period of 7.7+/-2.7 years, no patient died and 35 patients (42%) underwent aortic valve intervention. By multivariable Cox regression analysis, severe AS (> or = 4.0 m/s) and rapid progression of aortic jet velocity (> or = 0.2 m/s/year) were independent predictors of intervention. Cumulative intervention-free survival for patients with severe AS was 78+/-8% at 3 years and 48+/-10% at 5 years versus respectively 98+/-2% and 96+/-3% for patients with mild-to-moderate AS (log-rank: p<0.001).

CONCLUSIONS

Progression of congenital AS was relatively low in young adults compared to elderly with degenerative AS. Older age was associated with more rapid progression.