Prognostic value of N-terminal pro-B-type natriuretic peptide for conservatively and surgically treated patients with aortic valve stenosis

Early Intervention in Asymptomatic Aortic Stenosis: What Are We Waiting For?

Aortic stenosis (AS) contributes to significant cardiovascular morbidity and mortality worldwide, and the natural history from symptoms to ventricular decompensation, heart failure, and death has been well documented. For more than 2 decades, technologies including imaging and biomarkers have shown a promising ability to detect myocardial damage associated with AS before symptoms arise. Current treatment guidelines rely heavily on symptoms or ventricular decompensation as triggers for aortic valve intervention. There is increasing appreciation of the relationship between myocardial damage due to AS before the emergence of symptoms, and a number of published randomised trials suggest a benefit to early intervention in asymptomatic AS, with additional trials actively enrolling. Future treatment paradigms may incorporate early detection of ventricular damage by noninvasive new technologies as triggers for asymptomatic intervention. Enthusiasm for early aortic valve replacement should be tempered by consideration of the competing risks of early valve intervention, but an increasing preponderance of evidence continues to suggest that earlier intervention in AS is warranted.

Novel Biomarkers and Advanced Cardiac Imaging in Aortic Stenosis: Old and New

Currently, the symptomatic status and left ventricular ejection fraction (LVEF) play a crucial role in aortic stenosis (AS) assessment. However, the symptoms are often subjective, and LVEF is not a sensitive marker of left ventricle (LV) decompensation. Over the past years, the cardiac structure and function research on AS has increased due to advanced imaging modalities and potential therapies. New imaging parameters emerged as predictors of disease progression in AS. LV global longitudinal strain has proved useful for risk stratification in asymptomatic severe AS patients with preserved LVEF. The assessment of myocardial fibrosis by cardiac magnetic resonance is the most studied application and offers prognostic information on AS. Moreover, the usage of biomarkers in AS as objective measures of LV decompensation has recently gained more interest. The present review focuses on the transition from compensatory LV hypertrophy (H) to LV dysfunction and the biomarkers associated with myocardial wall stress, fibrosis, and myocyte death. Moreover, we discuss the potential impact of non-invasive imaging parameters for optimizing the timing of aortic valve replacement and provide insight into novel biomarkers for possible prognostic use in AS. However, data from randomized clinical trials are necessary to define their utility in daily practice.

Biomarkers Associated with Mortality in Aortic Stenosis: A Systematic Review and Meta-Analysis

The optimal timing of aortic valve replacement (AVR) remains controversial. Several biomarkers reflect the underlying pathophysiological processes in aortic stenosis (AS) and may be of use as mortality predictors. The aim of this systematic review and meta-analysis is to evaluate the blood biomarkers utilised in AS and assess whether they associate with mortality. PubMed and Embase were searched for studies reporting baseline biomarker level and mortality outcomes in patients with AS. A total of 83 studies met the inclusion criteria and were systematically reviewed. Of these, 21 reporting brain natriuretic peptide (BNP), N-terminal pro B-type natriuretic peptide (NT-proBNP), Troponin and Galectin-3 were meta-analysed. Pooled analysis demonstrated that all-cause mortality was significantly associated with elevated baseline levels of BNP (HR 2.59; 95% CI 1.95–3.44; p < 0.00001), NT-proBNP (HR 1.73; 95% CI 1.45–2.06; p = 0.00001), Troponin (HR 1.65; 95% CI 1.31–2.07; p < 0.0001) and Galectin-3 (HR 1.82; 95% CI 1.27–2.61; p < 0.001) compared to lower baseline biomarker levels. Elevated levels of baseline BNP, NT-proBNP, Troponin and Galectin-3 were associated with increased all-cause mortality in a population of patients with AS. Therefore, a change in biomarker level could be considered to refine optimal timing of intervention. The results of this meta-analysis highlight the importance of biomarkers in risk stratification of AS, regardless of symptom status.

Aortic valve calcification in the era of non-coding RNAs: The revolution to come in aortic stenosis management?

Aortic valve stenosis remains the most frequent structural heart disease, especially in the elderly. During the last decade, we noticed an important consideration and a huge number of publications related to the medical and surgical treatment of this disease. However, the molecular aspect of this degenerative issue has also been more widely studied recently. As evidenced in oncologic but also cardiac research fields, the emergence of microRNAs in the molecular screening and follow-up makes them potential biomarkers in the future, for the diagnosis, follow-up and treatment of aortic stenosis. Herein, we present a review on the implication of microRNAs in the aortic valve disease management. After listing and describing the main miRNAs of interest in the field, we provide an outline to develop miRNAs as innovative biomarkers and innovative therapeutic strategies, and describe a groundbreaking pre-clinical study using inhibitors of miR-34a in a pre-clinical model of aortic valve stenosis.

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.

Rise and fall of NT-proBNP in aortic valve intervention

Objectives

To describe the dynamics of N-terminal pro-B-type natriuretic peptide (NT-proBNP) from preoperative evaluation to 6-month follow-up in patients undergoing aortic valve intervention, and to evaluate NT-proBNP with regard to 1-year mortality.

Methods

At preoperative evaluation, we prospectively included 462 patients accepted for aortic valve intervention. The median time to surgical aortic valve replacement (SAVR; n=336) or transcatheter aortic valve implantation (TAVI; n=126) was 4 months. NT-proBNP was measured at enrolment for preoperative evaluation, on the day of surgery, postoperatively on day 1, day 3 and at the 6-month follow-up. Subgroups of patients undergoing SAVR with aortic regurgitation and aortic stenosis with and without coronary artery bypass were also analysed.

Results

NT-proBNP remained stable in all subgroups during the preoperative waiting period, but displayed a substantial transient early postoperative increase with a peak on day 3 except in the TAVI group, which peaked on day 1. At the 6-month follow-up, NT-proBNP had decreased to or below the preoperative level in all groups. In the SAVR group, NT-proBNP preoperatively and on postoperative days 1 and 3 revealed significant discriminatory power with regard to 1-year mortality (area under the curve (AUC)=0.79, P=0.0001; AUC=0.71, P=0.03; and AUC=0.79, P=0.002, respectively). This was not found in the TAVI group, which had higher levels of NT-proBNP both preoperatively and at the 6-month follow-up compared with the SAVR group.

Conclusions

The dynamic profile of NT-proBNP differed between patients undergoing TAVI and SAVR. NT-proBNP in the perioperative course was associated with increased risk of 1-year mortality in SAVR but not in TAVI.

Evaluation and Management of Aortic Stenosis for the Emergency Clinician: An Evidence-Based Review of the Literature

INTRODUCTION

Aortic stenosis is a common condition among older adults that can be associated with dangerous outcomes, due to both the disease itself and its influence on other conditions.

OBJECTIVE

This review provides an evidence-based summary of the current emergency department (ED) evaluation and management of aortic stenosis.

DISCUSSION

Aortic stenosis refers to significant narrowing of the aortic valve and can be caused by calcific disease, congenital causes, or rheumatic valvular disease. Symptoms of advanced disease include angina, dyspnea, and syncope. Patients with these symptoms have a much higher mortality rate than asymptomatic patients. Initial evaluation should include an electrocardiogram, complete blood count, basic metabolic profile, coagulation studies, troponin, brain natriuretic peptide, type and screen, and a chest radiograph. Transthoracic echocardiogram is the test of choice, but point-of-care ultrasound has been found to have good accuracy when a formal echocardiogram is not feasible. Initial management should begin with restoring preload and ensuring a normal heart rate, as both bradycardia and tachycardia can lead to clinical decompensation. For patients with high blood pressure and heart failure symptoms, nitrate agents may be reasonable, but hypotension should be avoided. Dobutamine can increase inotropy. For hypotensive patients, vasopressors should be used at the lowest effective dose. The treatment of choice is valve replacement, but extracorporeal membrane oxygenation and percutaneous balloon dilatation of the aortic valve have been described as temporizing measures.

CONCLUSION

Aortic stenosis is an important condition that can lead to dangerous outcomes and requires prompt recognition and disease-specific management in the ED.

Blood, tissue and imaging biomarkers in calcific aortic valve stenosis: past, present and future

PURPOSE OF REVIEW

Calcific aortic valve stenosis is the most prevalent valvular heart disease in the high-income countries. To this date, no medical therapy has been proven to prevent or to stop the progression of aortic valve stenosis. The physiopathology of aortic valve stenosis is highly complex and involves several signalling pathways, as well as genetic related factors, which delay the elaboration of effective pharmacotherapies. Moreover, it is difficult to predict accurately the progression of the valve stenosis and finding the optimal timing for aortic valve replacement remains challenging. Therefore, the present review makes an inventory of the most recent and promising circulating and imaging biomarkers related to the underlying mechanisms involved in the physiopathology of aortic valve stenosis, as well as the biomarkers associated with the left ventricular (LV) remodelling and subsequent dysfunction in patients with aortic valve stenosis.

RECENT FINDINGS

Over the last decade, several blood, tissue and imaging biomarkers have been investigated in aortic valve stenosis patients. At the aortic valve level, these biomarkers are mostly associated and/or involved with processes such as lipid infiltration and oxidation, chronic inflammation and fibrocalcific remodelling of the valve. Moreover, recent findings suggest that aging and sex hormones might interact with these multiple processes. Several studies demonstrated the usefulness of circulating biomarkers such as lipoprotein(a), brain natriuretic peptides and high-sensitivity cardiac troponin, which are very close to clinical routine. Furthermore, noninvasive imaging biomarkers including positron emission tomography and cardiac magnetic resonance, which provide a detailed view of the disease activity within the aortic valve and its repercussion on the left ventricle, may help to improve the understanding of aortic valve stenosis physiopathology and enhance the risk stratification. Other biomarkers such as von Willebrand factor and microRNAs are promising but further studies are needed to prove their additive value in aortic valve stenosis.

SUMMARY

Most of the biomarkers are used in research and thus, are still being investigated. However, some biomarkers including plasma level of lipoprotein(a), F-sodium fluoride, brain natriuretic peptides and high-sensitivity cardiac troponin can be or are very close to be used for the clinical management of patients with aortic valve stenosis. Moreover, a multibiomarker approach might provide a more global view of the disease activity and improve the management strategies of these patients.

Combined use of tissue Doppler imaging and natriuretic peptides as prognostic marker in asymptomatic aortic stenosis

INTRODUCTION

Tissue Doppler imaging (TDI) and N-terminal-pro-Brain Natriuretic Peptide (NT-proBNP) provides useful non-invasive information about left ventricle filling pressures and both have demonstrated to be a prognostic marker in some valve disease as aortic stenosis (AS).

OBJECTIVES

To assess the clinical value of combined TDI and NT-proBNP information in asymptomatic AS patients.

MATERIAL AND METHODS

Prospective study of 350 initially asymptomatic moderate to severe AS patients with: Mean aortic valve area 0.8 (0.3) cm², mean gradient 45(13) mmHg, ejection fraction 61 (9) %. Mean age: 74.6 (4.3) years. In all patients were determined NT-proBNP in the serum and TDI parameters the lateral mitral annulus. We considered clinical event the admission in the hospital due to symptoms related to AS (angina, heart failure or syncope) as well as surgical treatment or mortality.

RESULTS

After a mean follow-up of 29 (10) months, 165 (47%) patients suffered some clinical event. In order to predict clinical events, Bootstrap analysis determined the best cut-point value: E/E' ratio higher than 13 and NT-proBNP higher than 515pg/mL. E/E' ratio provides more specificity (78.9% vs 55.9%) and NT-proBNP provides more sensitivity (76.6% vs 43.7%). Combined use of both parameters provides the best prognostic information (sensitivity 75.6%, specificity 67.2%, negative predictive value 82.1%, positive predictive value 57.5%, accuracy 71.4%).

CONCLUSION

Combined use of TDI and natriuretic peptides information provides incremental prognostic value and is a useful tool to predict the prognosis in asymptomatic AS patients.

Usefulness of cardiovascular magnetic resonance imaging for the evaluation of valve opening and closing kinetics in aortic stenosis

AIMS

The aims of this study were : (i) to determine the feasibility and reproducibility of the measurement of valve kinetic parameters by cardiovascular magnetic resonance (CMR) and (ii) to examine the association between these parameters and markers of a poor prognosis in patients with aortic stenosis (AS).

METHODS AND RESULTS

Eight healthy control subjects and 71 patients with AS (0.60 cm(2) ≤ EOA ≤ 1.90 cm(2)) underwent transthoracic echocardiography (TTE) and CMR. The valve opening slope (OS) and closing slope (CS) were calculated from instantaneous effective orifice area (EOA) curves obtained by CMR. Intra- and inter-observer variability were 4.8 ± 3.9 and 5.0 ± 4.1%, respectively, for OS, 3.8 ± 2.9 and 4.0 ± 3.1% for CS. OS was significantly related to the plasma level of NT-pro-brain natriuretic peptide (BNP) (r = -0.36, P = 0.002), whereas the EOA or gradient were not.

CONCLUSION

This study demonstrates the excellent feasibility and reproducibility of CMR for the measurement of valve kinetic parameters in patients with AS. Larger studies are needed to confirm the incremental prognostic value of these new CMR parameters of aortic valve kinetics in patients with severe AS.

Improving assessment of aortic stenosis

"Degenerative" or calcific aortic stenosis is a complex, multifaceted, systemic disease that is not solely limited to the aortic valve but also includes reduced arterial compliance as well as alterations of left ventricular geometry and function. This particular nature of the disease underscores the need for a more comprehensive evaluation of disease severity going beyond the standard parameters routinely used to assess stenosis severity (i.e., peak jet velocity, pressure gradients, valve effective orifice area) or left ventricle function (i.e., left ventricular ejection fraction). The present paper thus proposes to review newer approaches to improve the quantification of disease severity taking into account the interrelation between the different valvular, arterial, and ventricular variables that may be responsible for the appearance of symptoms and/or poorer prognosis in patients with aortic stenosis.

High-sensitive troponin T and N-terminal-brain-natriuretic-peptide predict outcome in symptomatic aortic stenosis

OBJECTIVES

Aortic stenosis (AS) and atherosclerosis share similarities when it comes to risk factors and disease progression. Like in other heart diseases, we hypothesized that biomarkers like high-sensitive troponin T (hsTnT), N-terminal-pro-brain-natriuretic-peptide (NT-proBNP) and high-sensitive C-reactive protein (hsCRP) could be useful in risk stratification.

DESIGN

A total of 136 patients (57% men, mean age 74 years), referred for evaluation of AS (valve area 0.62 cm(2), left ventricular ejection fraction 64%) were consecutively enrolled in the study. The relationship between hsTnT, hsCRP and NT-proBNP, different echocardiographic parameters of AS and cardiac function were investigated as well as their relation to all-cause mortality.

RESULTS

In contrast to hsCRP, hsTnT and NT-proBNP were individually correlated with prognosis. Regression analysis identified diabetes and the combination of hsTnT and NT-proBNP as significant predictors of all-cause mortality. When analyzing patients without surgery separately, only the combination of hsTnT and NT-proBNP were identified as a significant predictor of all-cause mortality in multivariable analysis.

CONCLUSION

The combination of NT-proBNP and hsTnT came out as the strongest predictor of outcome irrespective of surgical treatment or not and could be of particular interest in risk-stratification in AS-patients. The results should be confirmed in prospective studies both in symptomatic and asymptomatic patients.

Comparison of goal-directed hemodynamic optimization using pulmonary artery catheter and transpulmonary thermodilution in combined valve repair: a randomized clinical trial

Our aim was to compare the effects of goal-directed therapy guided either by pulmonary artery catheter (PAC) or by transpulmonary thermodilution (TTD) combined with monitoring of oxygen transport on perioperative hemodynamics and outcome after complex elective valve surgery. Measurements and Main Results. Forty patients were randomized into two equal groups: a PAC group and a TTD group. In the PAC group, therapy was guided by mean arterial pressure (MAP), cardiac index (CI) and pulmonary artery occlusion pressure (PAOP), whereas in the TTD group we additionally used global end-diastolic volume index (GEDVI), extravascular lung water index (EVLWI), and oxygen delivery index (DO₂I). We observed a gradual increase in GEDVI, whereas EVLWI and PAOP decreased by 20–30% postoperatively (P < 0.05). The TTD group received 20% more fluid accompanied by increased stroke volume index and DO₂I by 15–20% compared to the PAC group (P < 0.05). Duration of mechanical ventilation was increased by 5.2 hrs in the PAC group (P = 0.04). Conclusions. As compared to the PAC-guided algorithm, goal-directed therapy based on transpulmonary thermodilution and oxygen transport increases the volume of fluid therapy, improves hemodynamics and DO₂I, and reduces the duration of respiratory support after complex valve surgery.

Elevated intraoperative expression of ventricular myosin light chain predicts heart failure after valve replacement surgery

BACKGROUND

It can be difficult to predict which patients will survive and recover cardiac function after valve replacement surgery. We hypothesized that the expression levels of ventricular myosin light chain (MLCv) might reflect the severity of disease or the extent of irreversible myocardial damage and might be useful for predicting the postoperative course. Thus, the aim of this study was to explore the relationship between MLCv expression in specimens obtained during valve replacement surgery and the postoperative New York Heart Association (NYHA) class.

METHODS

The levels of expression of the regulatory MLCv (MLC-2v) and MLC-1v in papillary muscle specimens from 80 patients who underwent valve replacement surgery for rheumatic valvular disease were evaluated by Western blot analysis.

RESULTS

The patients were similar with regard to the intraoperative expression of MLC-1v, regardless of postoperative NYHA class. The preoperative NYHA class, the end-systolic left ventricular internal dimension, and the intraoperative expression of MLC-2v emerged as independent risks factors for a NYHA class status of III/IV at 6 months after surgery, with an area under the receiver operating characteristic curve of 0.862.

CONCLUSION

The intraoperative level of MLC-2v expression was predictive of the patients' NYHA class after valve replacement surgery. This result suggests that future studies evaluating the use of preoperative specimens (such as biopsy or peripheral blood samples) for measurement of MLC-2v levels could lead to a valuable preoperative tool for the assessment of candidates for valve replacement.

Effects of rosuvastatin on progression of stenosis in adult patients with congenital aortic stenosis (PROCAS Trial)

Recent trials have failed to show that statin therapy halts the progression of calcific aortic stenosis (AS). We hypothesized that statin therapy in younger patients with congenital AS would be more beneficial, because the valve is less calcified. In the present double-blind, placebo-controlled trial, 63 patients with congenital AS (age 18 to 45 years) were randomly assigned to receive either 10 mg of rosuvastatin daily (n = 30) or matched placebo (n = 33). The primary end point was the progression of peak aortic valve velocity. The secondary end points were temporal changes in the left ventricular mass, ascending aortic diameter, and N-terminal pro-brain natriuretic peptide (NT-proBNP). The median follow-up was 2.4 years (interquartile range 1.9 to 3.0). The mean increase in peak velocity was 0.05 ± 0.21 m/s annually in the rosuvastatin group and 0.09 ± 0.24 m/s annually in the placebo group (p = 0.435). The annualized change in the ascending aorta diameter (0.4 ± 1.7 mm with rosuvastatin vs 0.5 ± 1.6 mm with placebo; p = 0.826) and left ventricular mass (1.1 ± 15.8 g with rosuvastatin vs -3.7 ± 30.9 g with placebo; p = 0.476) were not significantly different between the 2 groups. Within the statin group, the NT-proBNP level was 50 pg/ml (range 19 to 98) at baseline and 21 pg/ml (interquartile range 12 to 65) at follow-up (p = 0.638). NT-proBNP increased from 40 pg/ml (interquartile range 20 to 92) to 56 pg/ml (range 26 to 130) within the placebo group (p = 0.008). In conclusion, lipid-lowering therapy with rosuvastatin 10 mg did not reduce the progression of congenital AS in asymptomatic young adult patients. Interestingly, statins halted the increase in NT-proBNP, suggesting a potential positive effect of statins on cardiac function in young patients with congenital AS.

Aortic valve disease and treatment: the need for naturally engineered solutions

The aortic valve regulates unidirectional flow of oxygenated blood to the myocardium and arterial system. The natural anatomical geometry and microstructural complexity ensures biomechanically and hemodynamically efficient function. The compliant cusps are populated with unique cell phenotypes that continually remodel tissue for long-term durability within an extremely demanding mechanical environment. Alteration from normal valve homeostasis arises from genetic and microenvironmental (mechanical) sources, which lead to congenital and/or premature structural degeneration. Aortic valve stenosis pathobiology shares some features of atherosclerosis, but its final calcification endpoint is distinct. Despite its broad and significant clinical significance, very little is known about the mechanisms of normal valve mechanobiology and mechanisms of disease. This is reflected in the paucity of predictive diagnostic tools, early stage interventional strategies, and stagnation in regenerative medicine innovation. Tissue engineering has unique potential for aortic valve disease therapy, but overcoming current design pitfalls will require even more multidisciplinary effort. This review summarizes the latest advancements in aortic valve research and highlights important future directions.

Early hemodynamic and neurohormonal response after transcatheter aortic valve implantation

BACKGROUND

The conventional surgical aortic bioprostheses used for treatment of aortic stenosis (AS) are inherently stenotic in nature. The more favorable mechanical profile of the Medtronic CoreValve bioprosthesis may translate into a better hemodynamic and neurohormonal response.

PATIENTS AND METHODS

The early hemodynamic and neurohormonal responses of 56 patients who underwent successful transcatheter aortic valve implantation (TAVI) using the Medtronic CoreValve bioprosthesis for severe symptomatic AS were compared with those of 36 patients who underwent surgical aortic valve replacement (SAVR) using tissue valves in the same period.

RESULTS

At baseline, patients in the TAVI and SAVR group had comparable indexed aortic valve area (0.33 ± 0.1 vs 0.34 ± 0.1 cm² , respectively; P = .69) and mean transvalvular gradient (51.1 ± 16.5 vs 53.1 ± 14.3 mm Hg, respectively; P = .56). At 30-day follow-up, mean transvalvular gradient was lower in the TAVI group than in the SAVR group (10.3 ± 4 vs 13.1 ± 6.2 mm Hg, respectively; P = .015), and the indexed aortic valve area was larger in the TAVI group (1.0 ± 0.14 vs 0.93 ± 0.13 cm²/m²; P = .017). There was a trend toward a higher incidence of moderate patient-prosthesis mismatch in the surgical group compared with the TAVI group (30.5% vs 17.8%, respectively; P = .11). The overall incidence of prosthetic regurgitation (any degree) was higher in the TAVI group than in the SAVR group (85.7% vs 16.7%, respectively; P < .00001). The left ventricular mass index decreased after TAVI (175.1 ± 61.8 vs 165.6 ± 57.2 g/m²; P = .0003) and remained unchanged after SAVR (165.1 ± 50.6 vs 161 ± 64.8 g/m²; P = .81). Similarly, NT-ProBNP decreased after TAVI (3,479 ± 2,716 vs 2,533 ± 1,849 pg/mL; P = .033) and remained unchanged after SAVR (1,836 ± 2,779 vs 1,689 ± 1,533 pg/mL; P = .78). There was a modest correlation between natriuretic peptides and left ventricular mass index in the whole cohort (r = 0.4, P = .013).

CONCLUSION

In patients with severe AS, TAVI resulted in lower transvalvular gradients and higher valve areas than SAVR. Such hemodynamic performance after TAVI may have contributed to early initiation of a reverse cardiac remodeling process and a decrease in natriuretic peptides.

Insights into the use of biomarkers in calcific aortic valve disease

Calcific aortic valve disease (CAVD) is the most common acquired valvular disorder in developed countries. CAVD ranges from mild thickening of the valve, known as aortic valve sclerosis (AVSc), to severe impairment of the valve motion, which is termed aortic valve stenosis (AVS). The prevalence of CAVD is nearing epidemic status: its preceding stage, in which there is aortic sclerosis without obstruction of the left ventricular outflow, is present in almost 30% of adults aged over 65 years. As there is no existing medical therapy to treat or slow the progression of CAVD, surgery for advanced disease represents the only available treatment. Aortic valve replacement is the second most frequently performed cardiac surgical procedure after coronary artery bypass grafting, and consequently CAVD represents a major societal and economic burden. The pathophysiological development of CAVD is incompletely defined. At the present time, the major methods for its diagnosis are clinical examination, echocardiography, and cardiac catheterization. Yet, due to the multiple biological pathways leading to CAVD, there are many potential biomarkers that might be suitable for deriving clinically useful information regarding the presence, severity, progression, and prognosis of CAVD. Although at the present time the available data do not permit recommendations for clinicians, they do support a paradigm of screening patients based on multiple biomarkers to provide the information necessary to optimize future therapeutic interventions. This review summarizes the results of several studies investigating the value of potential biomarkers that have been used to predict the severity, progression, and prognosis of CAVD.

B-type natriuretic peptides and echocardiographic measures of cardiac structure and function

Echocardiography and the B-type natriuretic peptides (BNPs) provide powerful incremental assessment of cardiac function, clinical status, and outcome across the spectrum of cardiac disease. There is strong evidence to support their integrated use in the diagnosis and management of cardiovascular disease. Amino-terminal pro-B-type natriuretic peptide (NT-proBNP) or BNP may guide more effective use of echocardiography in screening for asymptomatic left ventricular dysfunction; Doppler echocardiography improves the accuracy of heart failure diagnosis in the setting of intermediate BNP or NT-proBNP levels. Combined assessment of peptides and echocardiography provides more powerful stratification of risk across all stages of heart failure, and integrated use of both tests may identify subjects with valvular disease at greatest risk for progression and guide decision-making for timely intervention.

Aortic stenosis

In developed countries, aortic stenosis is the most prevalent of all valvular heart diseases. A manifestation of ageing, the disorder is becoming more frequent as the average age of the population increases. Symptomatic severe disease is universally fatal if left untreated yet is consistent with a typical lifespan when mechanical relief of the stenosis is provided in a timely fashion. Management of mild disease, severe asymptomatic disease, and far advanced disease, and the effect of new percutaneous treatments, provide both controversy and exciting promise to care of patients with aortic stenosis. We discuss these issues in this Review.

Comparison of brain natriuretic peptide plasma levels versus logistic EuroSCORE in predicting in-hospital and late postoperative mortality in patients undergoing aortic valve replacement for symptomatic aortic stenosis

The accuracy of the logistic EuroSCORE (logES), a widely used risk prediction algorithm for cardiac surgery including aortic valve surgery, usually overestimates observed perioperative mortality. Elevated brain natriuretic peptide (BNP) in symptomatic patients with aortic stenosis (AS) is associated with a poor short-term outcome after aortic valve replacement. We aimed to compare BNP with the logES for predicting short- and long-term outcome in symptomatic patients with severe AS undergoing aortic valve replacement. We prospectively studied 144 consecutive patients referred for aortic valve replacement (42% women, 73 +/- 9 years, mean aortic gradient 51 +/- 18 mm Hg, and left ventricular ejection fraction 61 +/- 11%) undergoing either isolated aortic valve replacement (58%) or combined to bypass grafting. Both plasma BNP and logES was estimated before surgery. The median BNP plasma level and logES were 157 pg/ml (interquartile range [IQR] 61 to 440) and 6.6% (IQR 4.2 to 12.2), respectively. The perioperative mortality was 6% and the overall mortality by the end of the study was 13%. Patients with logES >10.1% (upper tertile) had a higher risk of dying over time (hazard ratio [HR] 2.86, p = 0.037), as had patients with BNP >312 pg/ml (HR 9.01, p <0.001). Discrimination (based on C statistic) and model performance (based on Akaike information criterion) were better for BNP than for logES. At the bivariable analysis, only BNP was an independent predictor of death (HR 8.2, p = 0.002). Preoperative BNP was even more accurate than logES in predicting outcome. In conclusion, in symptomatic patients with severe AS, high preoperative BNP plasma level and high logES confirm their predicting value for short- and long-term outcome.

NT-ProBNP predicts rhythm stability after cardioversion of lone atrial fibrillation

BACKGROUND

The aim of the present study was: (1) to determine the predictive value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) on the success of an elective direct-current cardioversion; and (2) to assess the ability to monitor rhythm stability after electrical cardioversion in patients with lone atrial fibrillation (AF).

METHODS AND RESULTS

Fifty-three patients with lone AF were provided with an Holter-ECG for a follow-up period of 4 weeks after elective cardioversion. NT-proBNP serum levels were measured before and 4 weeks after cardioversion. All patients presented with increased NT-proBNP serum levels (median 874 pg/ml, interquartile range 703-1,355) before cardioversion. Thirty patients were in sinus rhythm (SR) during follow-up. These patients showed a significant NT-proBNP-decrease (759 pg/ml, 618-1,139 to 318 pg/ml, 200-523, p<0.05). Nineteen patients experienced a relapse of AF. NT-proBNP was significantly higher prior to cardioversion in comparison to patients without relapse (p<0.05) and remained unchanged during follow-up (1,124 pg/ml, 925-1,542 vs 1,256 pg/ml, 945-1,509, p=NS). Four patients had short periods of silent AF detected by Holter ECG. These patients had a smaller decrease in NT-proBNP than patients with stable SR. The area under the curve of the receiver-operating characteristic curve was 0.8 for NT-proBNP to predict a successful cardioversion. Using an optimized cut-off level of 900 pg/ml, successful cardioversion can be predicted with high accuracy.

CONCLUSIONS

The probability of a successful cardioversion correlates inversely with NT-proBNP values. The short-term success of a cardioversion might be predicted by prior determination of NT-proBNP.

Heart failure in patients with aortic stenosis: Clinical and prognostic significance of carbohydrate antigen 125 and brain natriuretic peptide measurement

BACKGROUND

Brain natriuretic peptide (BNP) is related to symptomatic status and outcome in aortic stenosis (AS) patients. Carbohydrate antigen 125 (CA125) demonstrated recently a BNP-like behaviour in patients with congestive heart failure (CHF) but has never been studied in AS patients. We aimed to assess the role of CA125 and BNP in AS patients.

METHODS

CA125 and BNP blood levels, transthoracic echocardiography and independent evaluation of CHF symptoms were obtained in 64 consecutive patients (76+/-9 years; 35 males) with AS (valve area 0.9+/-0.3 cm(2)). A pre-specified combined end-point consisting of cardiac mortality, urgent aortic valve replacement and hospitalization for CHF was considered. The median follow-up was 8 months (interquartile range 4.5-10 months).

RESULTS

Both CA125 and BNP have accurately identified patients with III-IV NYHA class: area under the ROC curve was 0.85 for CA125 and 0.78 for BNP (best cut-offs of 10.3 U/mL and 254.64 pg/mL respectively) and were independently correlated to left ventricular ejection fraction. Fifty-two percent of patients with CA125>or=10.3 U/mL vs. 13% with CA125<10.3 U/mL (p<0.01) and 65% patients with BNP>or=254 pg/mL vs. 7% with BNP<254 pg/mL (p<0.001) have reached the end-point.

CONCLUSIONS

Both CA125 and BNP levels are significantly correlated with NYHA class and outcome in patients with AS. CA125 blood level assessment (less expensive) may improve the clinical management in this setting.

Review: Does lowering cholesterol have an impact on the progression of aortic stenosis?

Several studies suggest that atherosclerotic disease is not a focal disease restricted to culprit lesions in the intima of the arterial wall, but seems to act as a general disease affecting the entire cardiovascular system. Evolving research has lately focused on the atherosclerotic component in calcific aortic stenosis (AS) as it seems that the valve is affected in a pattern similar to that of the vasculature. The hope is therefore, that we someday in the management of patients with calcific AS can apply some of the same treatment strategies as in atherosclerotic vascular disease. This article reviews the pathophysiological mechanisms of calcific AS, reviews current clinical trials of statin use in aortic stenosis and reports on on-going trials, evaluating whether cholesterol lowering therapy can slow disease progression in different populations. Finally, we review if computerized tomography, biomarkers, and clinical characteristics such as left ventricular ejection fraction, can be useful in stratifying patients to potential benefit of statin therapy.

Use of natriuretic peptide assay in dyspnea

INTRODUCTION

Acute dyspnea is a common symptom in patients admitted to hospital via emergency department. Heart failure is a common cause with high morbidity and mortality, but diagnostically challenging. Improvement in diagnostic techniques is needed.

METHODS

Selective search of Medline.

RESULTS

B-type natriuretic peptide (BNP) and its N-terminal fragment (NT-proBNP) are extremely helpful in the diagnosis of heart failure in patients with acute dyspnea. The use of natriuretic peptide assay has also been shown to be cost-effective. Since plasma levels of natriuretic peptides reflect the extent of systolic and diastolic dysfunction, measurement of natriuretic peptides is helpful in estimating overall risk in patients with heart failure or acute myocardial infarction. They have also been used in the management of patients with valvular disease and in tailoring therapy in patients with heart failure.

DISCUSSION

BNP and NT-proBNP are quantitative markers of heart failure that are helpful for diagnosis, prognosis and treatment monitoring.

Amino-terminal pro-B-type natriuretic peptide testing for the diagnosis or exclusion of heart failure in patients with acute symptoms

When used for the evaluation of patients with acute symptoms in the emergency department setting, amino-terminal pro-B-type natriuretic peptide (NT-proBNP) testing is highly sensitive and specific for the diagnosis or exclusion of acute destabilized heart failure (HF), with results comparable to those reported for B-type natriuretic peptide (BNP) testing. When used for the diagnostic evaluation of the patient with possible HF, NT-proBNP testing returns information that may be superior to clinical judgment. However, the optimal application of NT-proBNP is in concert with history and physical examination, adjunctive testing, and with the knowledge of the differential diagnosis of an elevated NT-proBNP level. Studies indicate a dual use for NT-proBNP, both to exclude acute HF (where NT-proBNP concentrations <300 ng/L have a 98% negative predictive value), as well as to identify the diagnosis. To identify acute HF in patients with dyspnea, an age-independent NT-proBNP cut point of 900 ng/L has a similar value as that reported for a BNP value of 100 ng/L. However, age stratification of NT-proBNP using cut points of 450, 900, and 1,800 ng/L (for age groups of <50, 50-75, and >75 years) reduces false-negative findings in younger patients, reduces false-positive findings in older patients, and improves the overall positive predictive value of the marker without a change in overall sensitivity or specificity. Clinically validated, cost-effective algorithms for the use of NT-proBNP testing exist. Therefore, the logical use of NT-proBNP for the evaluation of the patient with suspected acute HF is useful, cost-effective, and may reduce adverse outcomes compared with standard clinical evaluation without natriuretic peptide testing.