Elevated growth differentiation factor 15 levels predict outcome in patients undergoing transcatheter aortic valve implantation

Multimarker Approach to Improve Risk Stratification of Patients Undergoing Transcatheter Aortic Valve Implantation

Background

A blood multimarker approach may be useful to enhance risk stratification in patients undergoing TAVI.

Objectives

The objective of this study was to determine the prognostic value of multiple blood biomarkers in transcatheter aortic valve implantation (TAVI) patients.

Methods

In this prospective study, several blood biomarkers of cardiovascular function, inflammation, and renal function were measured in 362 patients who underwent TAVI. The cohort was divided into 3 groups according to the number of elevated blood biomarkers (ie, ≥ median value for the whole cohort) for each patient before the procedure. Survival analyses were conducted to evaluate the association between blood biomarkers and risk of adverse event following TAVI.

Results

During a median follow-up of 2.5 (IQR: 1.9-3.2) years, 34 (9.4%) patients were rehospitalized for heart failure, 99 (27%) patients died, and 113 (31.2%) met the composite endpoint of all-cause mortality or heart failure rehospitalization. Compared to patients with 0 to 3 elevated biomarkers (referent group), those with 4 to 7 and 8 to 9 elevated biomarkers had a higher risk of all-cause mortality (HR: 1.54 [95% CI: 0.84-2.80], P = 0.16, and HR: 2.81 [95% CI: 1.53-5.15], P < 0.001, respectively) and of the composite endpoint (HR: 1.65 [95% CI: 0.95-2.84], P = 0.07, and HR: 2.67 [95% CI: 1.52-4.70] P < 0.001, respectively). Moreover, adding the number of elevated blood biomarkers into the clinical multivariable model provided significant incremental predictive value for all-cause mortality (Net Reclassification Index = 0.71, P < 0.001).

Conclusions

An increasing number of elevated blood biomarkers is associated with higher risks of adverse clinical outcomes following TAVI. The blood multimarker approach may be helpful to enhance risk stratification in TAVI patients.

Risk stratification using growth differentiation factor 15 in patients undergoing transcatheter aortic valve implantation

AIMS

Growth differentiation factor 15 (GDF15) shows potential predictive value in various cardiac conditions. We investigated relationships between GDF15 and clinical or procedural outcomes in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI) in order to propose clinically useful predictive risk stratification model.

METHODS

This prospective single-center registry enrolled 88 consecutive patients with severe symptomatic aortic stenosis treated with TAVI. Clinical parameters were collected and biomarkers including GDF-15 were measured within 24 h before TAVI. All relevant clinical outcomes according to the Valve Academic Research Consortium-2 were collected over the follow-up period.

RESULTS

The cohort included 52.3% of females. The mean age of study participants was 81 years; the mean Society of Thoracic Surgeons (STS) score and logistic EuroSCORE were 3.6% and 15.4%, respectively. The mortality over the entire follow-up period was 10.2%; no death was observed within the first 30 days following TAVI. Univariate analysis showed significant associations between GDF15 and mortality (P=0.0006), bleeding (P=0.0416) and acute kidney injury (P=0.0399). A standard multivariate logistic regression model showed GDF-15 as the only significant predictor of mortality (P=0.003); the odds ratio corresponding to an increase in GDF15 of 1000 pg/mL was 1.22. However, incremental predictive value was not observed when the STS score was combined with GDF15 in this predictive model.

CONCLUSIONS

Based on our observations, preprocedural elevated GDF15 levels are associated with increased mortality and demonstrate their additional value in predicting adverse clinical outcomes in a TAVI population.

Circulating Monocyte Subsets and Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR), as an alternative to open heart surgery, has revolutionized the treatment of severe aortic valve stenosis (AVS), the most common valvular disorder in the elderly. AVS is now considered a form of atherosclerosis and, like the latter, partly of inflammatory origin. Patients with high-grade AVS have a highly disturbed blood flow associated with high levels of shear stress. The immediate reopening of the valve during TAVR leads to a sudden restoration of a normal blood flow hemodynamic. Despite its good prognosis for patients, TAVR remains associated with bleeding or thrombotic postprocedural complications, involving mechanisms that are still poorly understood. Many studies report the close link between blood coagulation and inflammation, termed thromboinflammation, including monocytes as a major actor. The TAVR procedure represents a unique opportunity to study the influence of shear stress on human monocytes, key mediators of inflammation and hemostasis processes. The purpose of this study was to conduct a review of the literature to provide a comprehensive overview of the impact of TAVR on monocyte phenotype and subset repartition and the association of these parameters with the clinical outcomes of patients with severe AVS who underwent TAVR.

Elevated N-terminal pro C-type natriuretic peptide is associated with mortality in patients undergoing transcatheter aortic valve replacement

Background

Unlike N-terminal pro-B-type natriuretic peptide (NT-proBNP), which have been extensively studied, little is known about the role of N-terminal pro-C-type natriuretic peptide (NT-proCNP) for predicting survival post transcatheter aortic valve replacement (TAVR).

Methods

A total of 309 patients were included in the analysis. Patients were grouped into quartiles (Q1–4) according to the baseline NT-proCNP value. Blood for NT-proCNP analysis was obtained prior to TAVR procedure. The primary endpoint was mortality after a median follow-up of 32 months. Multivariable Cox proportional hazards regression models analyzed prognostic factors. The predictive capability was compared between NT-proBNP and NT-proCNP using receiver operator curve (ROC) analysis.

Results

A total of 309 subjects with the mean age of 76.8 ± 6.3 years, among whom 58.6% were male, were included in the analysis. A total of 58 (18.8%) patients died during follow-up. Cox multivariable analyses indicated society of thoracic surgeons (STS)-score was a strong independent predictor for mortality (hazard ratio (HR) 1.08, 95% confidential interval (CI) 1.05–1.12, P < 0.001). Elevated NT-proCNP was associated with a higher risk of cardiovascular mortality (HR 1.02, 95% CI 1.00–1.03, P = 0.025) and All-cause mortality (HR 1.01, 95% CI 1.00–1.03, P = 0.027), whereas NT-proBNP showed a small effect size on mortality. ROC analysis indicated that NT-proCNP was superior to NT-proBNP for TAVR risk evaluation in patients with left ventricular ejection fraction (LVEF) < 50% [(Area under the curve (AUC)-values of 0.79 (0.69; 0.87) vs. 0.59 (0.48; 0.69), P = 0.0453].

Conclusions

NT-proCNP and STS-Score were the independent prognostic factors of mortality among TAVR patients. Furthermore, NT-proCNP was superior to NT-proBNP for TAVR risk evaluation in patients with LVEF < 50%.

Trial registration NCT02803294, 16/06/2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02615-8.

Severe Aortic Valve Stenosis and Pulmonary Hypertension: A Systematic Review of Non-Invasive Ways of Risk Stratification, Especially in Patients Undergoing Transcatheter Aortic Valve Replacement

Patients with severe aortic valve stenosis and concomitant pulmonary hypertension show a significantly reduced survival prognosis. Right heart catheterization as a preoperative diagnostic tool to determine pulmonary hypertension has been largely abandoned in recent years in favor of echocardiographic criteria. Clinically, determination of echocardiographically estimated systolic pulmonary artery pressure falls far short of invasive right heart catheterization data in terms of accuracy. The aim of the present systematic review was to highlight noninvasive possibilities for the detection of pulmonary hypertension in patients with severe aortic valve stenosis, with a special focus on cardiovascular biomarkers. A total of 525 publications regarding echocardiography, cardiovascular imaging and biomarkers related to severe aortic valve stenosis and pulmonary hypertension were analyzed in a systematic database analysis using PubMed Central®. Finally, 39 publications were included in the following review. It was shown that the current scientific data situation, especially regarding cardiovascular biomarkers as non-invasive diagnostic tools for the determination of pulmonary hypertension in severe aortic valve stenosis patients, is poor. Thus, there is a great scientific potential to combine different biomarkers (biomarker scores) in a non-invasive way to determine the presence or absence of PH.

Myocardial hypoxic stress mediates functional cardiac extracellular vesicle release

AIMS

Increased shedding of extracellular vesicles (EVs)-small, lipid bilayer-delimited particles with a role in paracrine signalling-has been associated with human pathologies, e.g. atherosclerosis, but whether this is true for cardiac diseases is unknown.

METHODS AND RESULTS

Here, we used the surface antigen CD172a as a specific marker of cardiomyocyte (CM)-derived EVs; the CM origin of CD172a+ EVs was supported by their content of cardiac-specific proteins and heart-enriched microRNAs. We found that patients with aortic stenosis, ischaemic heart disease, or cardiomyopathy had higher circulating CD172a+ cardiac EV counts than did healthy subjects. Cellular stress was a major determinant of EV release from CMs, with hypoxia increasing shedding in in vitro and in vivo experiments. At the functional level, EVs isolated from the supernatant of CMs derived from human-induced pluripotent stem cells and cultured in a hypoxic atmosphere elicited a positive inotropic response in unstressed CMs, an effect we found to be dependent on an increase in the number of EVs expressing ceramide on their surface. Of potential clinical relevance, aortic stenosis patients with the highest counts of circulating cardiac CD172a+ EVs had a more favourable prognosis for transcatheter aortic valve replacement than those with lower counts.

CONCLUSION

We identified circulating CD172a+ EVs as cardiac derived, showing their release and function and providing evidence for their prognostic potential in aortic stenosis patients.

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.

Predicting and measuring mortality risk after transcatheter aortic valve replacement

Introduction: Over the last decade, transcatheter aortic valve replacement (TAVR) has emerged as a treatment option for most patients with severe symptomatic aortic stenosis (AS). With growing indications and exponential increase in the number of TAVR procedures, it is important to be able to accurately predict mortality after TAVR.Areas covered: Herein, we review the surgical and TAVR-specific mortality prediction models (MPMs) and their performance in their original derivation and external validation cohorts. We then discuss the role of other important risk assessment tools such as frailty, echocardiographic parameters, and biomarkers in patients, being considered for TAVR.Expert opinion: Conventional surgical MPMs have suboptimal predictive performance and are mis-calibrated when applied to TAVR populations. Although a number of TAVR-specific MPMs have been developed, their utility is also limited by their modest discriminative ability when applied to populations external to their original derivation cohorts. There is an unmet need for robust TAVR MPMs that accurately predict post TAVR mortality. In the interim, heart teams should utilize the currently available TAVR-specific MPMs in conjunction with other prognostic factors, such as frailty, echocardiographic or computed tomography (CT) imaging parameters, and biomarkers for risk assessment of patients, being considered for TAVR.

Baseline NT-proBNP Accurately Predicts Symptom Response to Transcatheter Aortic Valve Implantation

Background

Up to 30% of patients undergoing transcatheter aortic valve implantation (TAVI) experience minimal symptomatic benefit or die within 1 year, indicating an urgent need for enhanced patient selection. Previous analyses of baseline NT‐proBNP (N‐terminal pro‐brain natriuretic peptide) and TAVI outcomes have assumed a linear relationship, yielding conflicting results. We reexamined the relationship between baseline NT‐proBNP and symptomatic improvement after TAVI.

Methods and Results

Symptom status, clinical and echocardiographic data, and baseline NT‐proBNP were reviewed from 144 consecutive patients undergoing TAVI for severe symptomatic aortic stenosis. The primary end point was change in New York Heart Association functional class at 1 year. There was a nonlinear, inverted‐U relationship between log‐baseline NT‐proBNP and post‐TAVI change in NYHA class (R²=0.4559). NT‐proBNP thresholds of <800 and >10 000 ng/L accurately predicted no symptomatic improvement at 1 year (sensitivity 88%, specificity 83%, positive predictive value 72%, negative predictive value 93%). In adjusted analyses, baseline NT‐proBNP outside this “sweet‐spot” range was the only factor independently associated with poor functional outcome (high: NT‐proBNP >10 000 ng/L, odds ratio [OR], 65; 95% CI, 6–664; low: NT‐proBNP <800 ng/L, OR, 73; 95% CI, 7–738).

Conclusions

Baseline NT‐proBNP is a useful prognostic marker to predict poor symptom relief after TAVI and may indicate when intervention is likely to be futile. Both low (<800 ng/L) and very high (>10 000 ng/L) levels are strongly associated with poor functional outcome, suggesting an alternative cause for symptoms in the former scenario and an irrevocably diseased left ventricle in the latter. Further evaluation of this relationship is warranted.

Growth Differentiation Factor 15 in Severe Aortic Valve Stenosis: Relationship with Left Ventricular Remodeling and Frailty

Background: Frailty is an important outcome predictor in patients with aortic stenosis who are candidates for transcatheter or surgical aortic valve replacement (AVR). Growth/differentiation factor 15 (GDF15) is a cytokine playing a role in the pathophysiology of ventricular remodeling. We assessed its potential role as an independent soluble biomarker of frailty in these patients. Methods: We studied 62 patients (age, mean 79 years, 95% confidence interval (CI) 77-81; 54.8% female) with severe aortic valve stenosis and candidates for AVR. We systematically assessed pre-intervention GDF15 levels for their relationship with frailty (Katz score) and echocardiographic parameters of left ventricular dysfunction/remodeling. Fifteen hypertensive patients with left ventricular (LV) hypertrophy served as controls. Results: Patients with aortic valve stenosis featured higher GDF15 levels than controls (1773, 95% CI 1574-1971 pg/mL vs. 775, 95% CI 600-950 pg/mL, respectively, p < 0.0001). Subjects in the upper GDF15 tertile were older (p = 0.004), with a more advanced NYHA functional class (p = 0.04) and a higher prevalence of impaired renal function (p = 0.004). Such patients also showed a higher frailty score (p = 0.04) and higher indices of LV dysfunction, including reduced global longitudinal strain (p = 0.01) and a higher left ventricular mass (p = 0.001). GDF15 was significantly related to the Katz score, and predicted (OR 1.05; 95% CI 0.9-1.1; p = 0.03) a low (<5) Katz score, independent of the relationship with LV mass, age, renal function or indices of LV dysfunction. Conclusions: GDF15 is increased in patients with severe aortic stenosis and appears to be a soluble correlate of patients' frailty, independent of indices of left ventricular dysfunction.

Biomarkers Associated With Aortic Valve Calcification: Should We Focus on Sex Specific Processes?

Objective

Circulating biomarkers are useful in detection and monitoring of cardiovascular diseases. However, their role in aortic valve disease is unclear. Mechanisms are rapidly elucidated and sex differences are suggested to be involved. Therefore, we sought to identify biomarkers involved in aortic valve calcification (AVC) stratified by sex.

Methods

Blood samples of 34 patients with AVC (without further overt cardiovascular disease, including absence of hemodynamic consequences of valvular calcification) were compared with 136 patients without AVC. AVC was determined using computed tomography calcium scoring. Circulating biomarkers were quantified using a novel antibody-based method (Olink Proseek Multiplex Cardiovascular Panel I) and 92 biomarkers were compared between patients with and without AVC.

Results

In the overall population, Interleukin-1 Receptor Antagonist and pappalysin-1 were associated with increased and decreased odds of having AVC. These differences were driven by the male population [IL1RA: OR 2.79 (1.16-6.70), p = 0.022; PAPPA: OR 0.30 (0.11-0.84), p = 0.021]. Furthermore, TNF-related activation-induced cytokine (TRANCE) and fibroblast growth factor-23 were associated decreased odds of having AVC, and monocyte chemotactic protein-1 was associated with increased odds of having AVC [TRANCE: OR 0.32 (0.12-0.80), p = 0.015; FGF23: OR 0.41 (0.170-0.991), p = 0.048; MCP1: OR 2.64 (1.02-6.81), p = 0.045]. In contrast, galanin peptides and ST2 were associated with increased odds of having AVC in females [GAL: OR 12.38 (1.31-116.7), p = 0.028; ST2: OR13.64 (1.21-153.33), p = 0.034].

Conclusion

In this exploratory study, we identified biomarkers involved in inflammation, fibrosis and calcification which may be associated with having AVC. Biomarkers involved in fibrosis may show higher expression in females, whilst biomarkers involved in inflammation and calcification could associate with AVC in males.

Periprocedural Changes of NT-proBNP Are Associated With Survival After Transcatheter Aortic Valve Implantation

Background

Cardiovascular biomarkers constitute promising tools for improved risk stratification and prediction of outcome in patients undergoing transcatheter aortic valve implantation. We examined the association of periprocedural changes of NT‐proBNP (N‐terminal pro–B‐type natriuretic peptide) with survival after transcatheter aortic valve implantation.

Methods and Results

NT‐proBNP levels were measured in 704 patients before transcatheter aortic valve implantation and at discharge. Patients were grouped as responders and nonresponders depending on an NT‐proBNP–based ratio (postprocedural NT‐proBNP at discharge/preprocedural NT‐proBNP). Overall, 376 of 704 patients showed a postprocedural decrease in NT‐proBNP levels (NT‐proBNP ratio <1). Responders and nonresponders differed significantly regarding median preprocedural (2822 versus 1187 pg/mL, P<0.001) and postprocedural (1258 versus 3009 pg/mL, P<0.001) NT‐proBNP levels. Patients in the nonresponder group showed higher prevalence of atrial fibrillation (47.0% versus 39.4%, P=0.042), arterial hypertension (94.2% versus 87.5%, P=0.002), renal impairment (77.4% versus 69.1%, P=0.013), and peripheral artery disease (24.4% versus 14.6%, P=0.001). In contrast, patients in the responder group had higher prevalence of moderately reduced left ventricular ejection fraction (17.3% versus 11.0%, P=0.017), lower calculated aortic valve area (0.7 versus 0.8 cm², P<0.001), and higher mean pressure gradient (41 versus 35 mm Hg, P<0.001). Median follow‐up was 22.6 months. Kaplan–Meier analysis showed a highly significant survival benefit for the responder group compared with the nonresponder group (log‐rank test, P<0.001).

Conclusions

A ratio based on periprocedural changes of NT‐proBNP is a simple tool for better risk stratification and is associated with survival in patients after transcatheter aortic valve implantation.

Growth Differentiation Factor-15 (GDF-15) is a Biomarker of Muscle Wasting and Renal Dysfunction in Preoperative Cardiovascular Surgery Patients

Frailty and sarcopenia increase the risk of complications and mortality when invasive treatment such as cardiac surgery is performed. Growth differentiation factor-15 (GDF-15) involves various pathophysiological conditions including renal dysfunction, heart failure and cachexia. We investigated the pathophysiological roles of preoperative GDF-15 levels in cardiovascular surgery patients. Preoperative skeletal muscle index (SMI) determined by bioelectrical impedance analysis, hand-grip strength, 4 m gait speed, and anterior thigh muscle thickness (TMth) measured by echocardiography were assessed in 72 patients (average age 69.9 years) who underwent cardiovascular surgery. The preoperative serum GDF-15 concentration was determined by enzyme-linked immunosorbent assay. Circulating GDF-15 level was correlated with age, brain natriuretic peptide, and estimated glomerular filtration rate (eGFR). It was also negatively correlated with SMI, hand-grip strength, and anterior TMth. In multivariate analysis, eGFR and anterior TMth were the independent determinants of GDF-15 concentration even after adjusting for age, sex, and body mass index. Alternatively, the GDF-15 level was an independent determinant of eGFR and anterior TMth. We concluded that preoperative GDF-15 levels reflect muscle wasting as well as renal dysfunction in preoperative cardiovascular surgery patients. GDF-15 may be a novel biomarker for identify high-risk patients with muscle wasting and renal dysfunction before cardiovascular surgery.

Biomarkers in Aortic Valve Stenosis and their Clinical Significance in Transcatheter Aortic Valve Implantation

Aortic valve stenosis is one of the most common valvular heart disorders and the prevalence will rise as the population ages. Once symptomatic patients with aortic valve stenosis tend to fare worse with high mortality rates. Aortic valve replacement is indicated in these patients and besides the standard surgical replacement, a less invasive approach, transcatheter aortic valve implantation, has gained momentum and has showed promising and solid results in patients with high surgical risk. An important aspect of evaluating patients with aortic valve stenosis is the ability to choose the best possible candidate for the procedure. In addition, predicting the short and long-term clinical outcomes after the valve replacement could offer the treating physicians a better insight and provide information for optimal therapy. Biomarkers are biological parameters that can be objectively measured and evaluated as indicators of normal biological processes and are easily monitored. The aim of this review is to critically assess some of the most widely used biomarkers at present (natriuretic peptides, troponins, C-reactive protein) and provide an insight in novel biomarkers that are currently being investigated (galectin-3, growth differentiation factor-15, microRNAs) for possible diagnostic and prognostic use in aortic valve stenosis and transcatheter aortic valve implantation respectively.

Clinical Implications of Serum Biomarkers of Cardiac Stress in Aortic Stenosis

PURPOSE OF REVIEW

The purpose of this review is to outline the relationship between serum biomarkers of cardiac stress and the pathophysiologic progression of aortic stenosis, to identify studies exploring the utility of biomarkers in the risk stratification and management of patients with aortic stenosis, and to highlight the biomarkers most practical to management of patients with aortic stenosis.

RECENT FINDINGS

Several biomarkers have been identified that reflect various aspects of the pathogenesis of calcific aortic stenosis, subsequent hemodynamic obstruction leading to myocardial remodeling, oxidative stress and injury, and concomitant systemic inflammation. These markers are associated with adverse outcomes in aortic stenosis and offer incremental value in risk prediction over traditional clinical assessment for aortic stenosis. NTproBNP and troponin are the most rigorously studied serum biomarkers in aortic stenosis, and only NTproBNP is currently reflected in any major guideline on aortic stenosis management. Serum biomarkers show promise in guiding management of aortic stenosis, but still require significant prospective investigation before they can be incorporated in major guidelines.

Meta-Analysis of Impact of Baseline N-TerminalPro-Brain Natriuretic Peptide Levels on SurvivalAfter Transcatheter Aortic Valve Implantation for Aortic Stenosis

We performed a meta-analysis of currently available studies investigating impact of baseline N-terminal pro-brain natriuretic peptide (NT-proBNP) on mortality after transcatheter aortic valve implantation (TAVI) for aortic stenosis (AS). MEDLINE and EMBASE were searched through August 2018 using PubMed and OVID. Studies considered for inclusion met the following criteria: the design was a study researching impact of baseline NT-proBNP levels on survival; the study population was patients underwent TAVI for AS; outcomes included all-cause mortality. For each study, we directly extracted odds ratio (ORs) or hazard ratios (HRs) of mortality (for high vs low baseline NT-proBNP); and generated ORs using mortality rates in both patients with high and low levels of baseline NT-proBNP. Study-specific estimates were combined using inverse variance-weighted averages of logarithmic ORs/HRs in the random-effects model. We identified 16 eligible studies including a total of 3,679 patients who underwent TAVI for AS. Pooled analyses demonstrated that high levels of baseline NT-proBNP were associated with a statistically nonsignificant increase in early (30-day or 2-month) mortality (pooled OR, 1.60; 95% confidence interval, 0.84 to 3.04; p = 0.15) and a statistically significant increase in midterm (6-month to 4-year) mortality (pooled OR/HR, 1.88; 95% confidence interval, 1.54 to 2.28; p < 0.00001). Although funnel-plot asymmetry suggesting publication bias was detected, adjusting for funnel-plot asymmetry indicated an association of high levels of baseline NT-proBNP with a still significant increase in midterm mortality. In conclusion, high levels of baseline NT-proBNP predict increased midterm, not early, mortality after TAVI for AS.

Impact of Left Ventricular Diastolic Dysfunction and Biomarkers on Pulmonary Hypertension in Patients with Severe Aortic Stenosis

Background: Severe aortic stenosis (AS) complicated by pulmonary hypertension (PH) is associated with poor outcomes after surgical aortic valve replacement (AVR). There is still scarce information about predictors of secondary PH in this group of patients. Objectives: The aim of this study was to investigate the prognostic impact of biomarkers together with conventional Doppler echocardiographic parameters of left ventricular diastolic function on elevated pulmonary systolic pressure (PSP) in severe AS patients before surgical AVR. Methods: Sixty patients with severe isolated AS (aortic valve area <1 cm²) underwent echocardiography, N-terminal pro B-type natriuretic peptide (NT-proBNP) and growth differentiation factor-15 (GDF-15) measurements before AVR. PSP, left ventricular ejection fraction (LV EF), parameters of LV diastolic function (E/E’ ratio, mitral valve deceleration time (MV DT) and left atrial (LA) volume) were evaluated. PH was defined as an estimated PSP ≥ 45 mmHg. Results: Of the 60 patients, 21.7% with severe isolated AS had PH with PSP ≥ 45 mmHg (58.5 ± 11.2 mmHg). LV EF did not differ between groups and was not related to an elevated PSP (50 ± 8 vs. 49 ± 8%, p = 0.58). Parameters of LV diastolic dysfunction (E/E’ ratio > 14 (OR 6.00; 95% CI, 1.41–25.48; p = 0.009), MV DT ≤ 177.5 ms (OR 9.31; 95% CI, 2.06–41.14; p = 0.001), LA volume > 100 mL (OR 9.70; 95% CI, 1.92–49.03; p = 0.002)) and biomarkers (NT-proBNP > 4060 ng/L (OR 12.54; 95% CI, 2.80–55.99; p < 0.001) and GDF-15 > 3393 pg/mL (OR 18.33; 95% CI, 2.39–140.39; p = 0.001)) were significantly associated with elevated PSP in severe AS. Conclusions: Left ventricular diastolic dysfunction and elevated biomarkers levels could predict the development of pulmonary hypertension in patients with severe aortic stenosis. Elevation of biomarkers paired with worsening of LV diastolic dysfunction could help to stratify patients for earlier surgical treatment before the development of pulmonary hypertension.

Proteomic Biomarkers for Incident Aortic Stenosis Requiring Valvular Replacement

Background:

Aortic valve stenosis (AS) is the most common indication for cardiac valve surgery; untreated AS is linked to high mortality. The etiological background of AS is unknown. Previous human studies were typically based on case-control studies. Biomarkers identified in prospective studies could lead to novel mechanistic insights.

Methods:

Within a large population survey with blood samples obtained at baseline, 334 patients were identified who later underwent surgery for AS (median age [interquartile range], 59.9 [10.4] years at survey and 68.3 [12.7] at surgery; 48% female). For each case, 2 matched referents were allocated. Plasma was analyzed with the multiplex proximity extension assay for screening of 92 cardiovascular candidate proteins. Conditional logistic regression models were used to assess associations between each protein and AS, with correction for multiple testing. A separate set of 106 additional cases with 212 matched referents was used in a validation study.

Results:

Six proteins (growth differentiation factor 15, galectin-4, von Willebrand factor, interleukin 17 receptor A, transferrin receptor protein 1, and proprotein convertase subtilisin/kexin type 9) were associated with case status in the discovery cohort; odds ratios ranged from 1.25 to 1.37 per SD increase in the protein signal. Adjusting the multivariable models for classical cardiovascular risk factors at baseline yielded similar results. Subanalyses of case-referent triplets (n=133) who showed no visible coronary artery disease at the time of surgery in the index person supported associations between AS and growth differentiation factor 15 (odds ratio, 1.40; 95% confidence interval, 1.10-1.78) and galectin-4 (odds ratio, 1.27; 95% confidence interval, 1.02-1.59), but these associations were attenuated after excluding individuals who donated blood samples within 5 years before surgery. In triplets (n=201), which included index individuals with concurrent coronary artery disease at the time of surgery, all 6 proteins were robustly associated with case status in all sensitivity analyses. In the validation study, the association of all but 1 (interleukin 17 receptor A) of these proteins were replicated in patients with AS with concurrent coronary artery disease but not in patients with AS without coronary artery disease.

Conclusions:

We provide evidence that 5 proteins were altered years before AS surgery and that the associations seem to be driven by concurrent atherosclerotic disease.

GDF-15 (Growth Differentiation Factor 15) Is Associated With Lack of Ventricular Recovery and Mortality After Transcatheter Aortic Valve Replacement

BACKGROUND

Recent data suggest that circulating biomarkers may predict outcome in patients undergoing transcatheter aortic valve replacement (TAVR). We examined the association between inflammatory, myocardial, and renal biomarkers and their role in ventricular recovery and outcome after TAVR.

METHODS AND RESULTS

A total of 112 subjects undergoing TAVR were included in the prospective registry. Plasma levels of B-type natriuretic peptide, hs-TnI (high-sensitivity troponin I), CRP (C-reactive protein), GDF-15 (growth differentiation factor 15), GAL-3 (galectin-3), and Cys-C (cystatin-C) were assessed before TAVR and in 100 sex-matched healthy controls. Among echocardiographic parameters, we measured global longitudinal strain, indexed left ventricular mass, and indexed left atrial volume. The TAVR group included 59% male, with an average age of 84 years, and 1-year mortality of 18%. Among biomarkers, we found GDF-15 and CRP to be strongly associated with all-cause mortality (P<0.001). Inclusion of GDF-15 and CRP to the Society of Thoracic Surgeons score significantly improved C index (0.65-0.79; P<0.05) and provided a category-free net reclassification improvement of 106% at 2 years (P=0.01). Among survivors, functional recovery in global longitudinal strain (>15% improvement) and indexed left ventricular mass (>20% decrease) at 1 year occurred in 48% and 22%, respectively. On multivariate logistic regression, lower baseline GDF-15 was associated with improved global longitudinal strain at 1 year (hazard ratio=0.29; P<0.001). Furthermore, improvement in global longitudinal strain at 1 month correlated with lower overall mortality (hazard ratio=0.45; P=0.03).

CONCLUSIONS

Elevated GDF-15 correlates with lack of reverse remodeling and increased mortality after TAVR and improves risk prediction of mortality when added to the Society of Thoracic Surgeons score.

Can Blood Biomarkers Help Predicting Outcome in Transcatheter Aortic Valve Implantation?

Transcatheter aortic valve implantation (TAVI) has become the method of choice for patients with severe aortic valve stenosis, who are ineligible or at high risk for surgery. In this high risk patient population, early and late mortality and rehospitalization rates after TAVI are still relatively high. In spite of recent improvements in procedural TAVI, and establishment of risk models for poor outcome, determining individual risk remains challenging. In this context, current data from several small studies strongly suggest that blood biomarkers of myocardial injury, cardiac mechanical stretch, inflammation, and hemostasis imbalance might play an important role by providing informations on patient risk at baseline, and postprocedural progression of patient clinical conditions from days up to years post-TAVI. Although the role of biomarkers for predicting survival post-TAVI remains to be validated in large randomized studies, implementing biomarkers in clinical practice might improve risk stratification, thereby further reducing TAVI-associated morbidity and mortality.

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.

Soluble ST2 for Risk Stratification and the Prediction of Mortality in Patients Undergoing Transcatheter Aortic Valve Implantation

This study aimed to assess the prognostic value of soluble ST2 (sST2) for risk stratification in patients undergoing transcatheter aortic valve implantation (TAVI). In 461 patients undergoing TAVI, sST2 was determined at baseline and categorized into quartiles. An optimum cutoff of 29 ng/ml was calculated. Primary end point was 1-year all-cause mortality. Results were validated in an independent cohort. Patients with sST2 >29 ng/ml had an increased 30-day (9.7% vs 4.6%, p = 0.043) and 1-year mortality (38.1% vs 21.8%, p = 0.001). In accordance, patients with N-terminal pro-brain natriuretic peptide (NT-proBNP) >8145 pg/ml revealed a comparable 30-day mortality (7.9% vs 4.7%, p = 0.189) and 1-year mortality (39.5% vs 21.0%, p <0.001). In univariate regression analysis, sST2 and NT-proBNP were associated with increased mortality risk. In multivariate regression analysis, independent predictors of mortality were logistic EuroSCORE, chronic renal failure, left ventricular ejection fraction, and sST2. In receiver operating characteristic curve analysis, sST2 did not provide incremental prognostic information beyond that obtained from surgical risk scores such as the STS-PROM or NT-proBNP. Similar findings could be achieved in an independent validation cohort. In conclusion, sST2 is independently associated with adverse outcome after TAVI but was not superior to NT-proBNP or surgical risk scores for the prediction of postprocedural outcomes.

Intermediate CD14++CD16+ monocytes decline after transcatheter aortic valve replacement and correlate with functional capacity and left ventricular systolic function

Background

Transcatheter aortic valve replacement (TAVR) is the method of choice for patients with severe aortic valve stenosis, who are ineligible or at high risk for surgery. Though TAVR leads to a significant reduction in mortality, a notable amount of patients are re-hospitalized early after TAVR. Parameters or biomarkers predicting outcome are therefore needed to identify patients who benefit most. Specific monocyte subsets have been associated with cardiovascular diseases and were shown to possess prognostic value.

Methods

Peripheral blood was drawn before and after transfemoral TAVR with the self-expanding CoreValve, Boston Lotus or the balloon-expanding Edwards Sapien prosthesis. Classical (CD14⁺⁺CD16⁻), intermediate (CD14⁺⁺CD16⁺) and non-classical (CD14⁺CD16⁺⁺) monocyte subsets were determined by flow cytometry. Transthoracic echocardiography was performed before, early after as well as 3 months after the TAVR procedure.

Results

No significant differences in the absolute monocyte counts were found after TAVR. A significant decline in the intermediate monocyte population was though observed early after TAVR (pre 4.01±0.38%, post 2.803±0.34%, p≤0.05). Creatinine levels stayed stable after TAVR procedure and intermediate monocytes were associated with worse renal function. Monocyte decline was not related to changes in CRP-, noradrenaline, cortisol or aldosterone-levels. The amount of intermediate monocytes correlated with worse cardiac function and predicted the possibility to reach an improvement in NYHA functional class at 3 months after TAVR.

Conclusions

A significant decline of intermediate monocytes occurs shortly after TAVR. High levels of intermediate monocytes were associated with worse cardiac function and predicted poor functional capacity, hinting at a possible prognostic value.

Osteopontin predicts clinical outcome in patients after treatment of severe aortic stenosis with transcatheter aortic valve implantation (TAVI)

Objective

Osteopontin (OPN) is an extracellular matrix protein that plays an integral role in myocardial remodelling and has previously been shown to be a valuable biomarker in cardiovascular disease. Because of the concentric myocardial hypertrophy associated with severe, symptomatic aortic stenosis (AS), we hypothesised that OPN expression may have a prognostic value in patients undergoing transcatheter aortic valve implantation (TAVI).

Methods

We prospectively included 217 patients undergoing TAVI between February 2011 and December 2013 with a median follow-up of 349 days. Twenty healthy individuals from the same age range free from structural heart disease served as controls. The primary endpoint for the analysis was survival time.

Results

Median preprocedural OPN levels (675 ng/mL; IQR 488.5–990.5 ng/mL) were significantly higher in patients with severe aortic valve stenosis compared with healthy controls (386 ng/mL; IQR 324.5–458, p<0.001). Patients with increased OPN values showed at baseline a decreased 6 min walk test performance, increased rates of atrial arrhythmia, and an increased risk of death during follow-up (HR 2.2; 95% CI 1.3 to 3.5 for the comparison of the highest vs lowest OPN quartile). Multiple Cox regression analysis demonstrated that OPN improves the prediction of an adverse prognosis further than N-terminal probrain natriuretic peptide.

Conclusions

OPN levels at baseline are associated with adverse outcomes in patients with severe, symptomatic AS undergoing TAVI.

Preprocedural but not periprocedural high-sensitive Troponin T levels predict outcome in patients undergoing transcatheter aortic valve implantation

AIM

Risk assessment of patients undergoing transcatheter aortic valve implantation (TAVI) remains difficult. Biomarkers have been shown to provide potential prognostic information. Here, we aimed to analyze whether the biomarker high-sensitivity Troponin T (hsTNT) could be used to improve risk stratification.

METHOD

We prospectively enrolled 267 patients undergoing TAVI. Biomarkers (hsTNT and NTproBNP) were measured 1 day before, and 3 and 7 days postprocedure. All possible prognostic factors upon survival time were analyzed by Cox regression analysis.

RESULTS

A total of 259 patients (mean age 82±6.1 years) were available for complete follow-up. The median Logistic EuroSCORE (Log ES) and Log ES II were 21.16% (Q1=13.92; Q3=34.27) and 6.42% (Q1=3.89; Q3=11.07), respectively. Median follow-up was 290 (Q1=88; Q3=529) days. A total of 71 deaths occurred during follow-up, and the 30-day mortality was 5.8%. Median baseline hsTNT was 27.4 pg/mL (Q1=16.2; Q3=46 pg/mL). From all potential mortality-associated factors, only preprocedural hsTNT level (P=.001), elevated Log ES (P=.03) as well as acute kidney injury (P<.001) and chronic obstructive pulmonary disease (COPD) (P=.039) emerged as independent prognostic parameters for adverse outcome. We also tested whether the Valve Academic Research Consortium-2 (VARC-II) cutoff for myocardial damage (hsTNT peak value exceeding 15× the upper reference limit + at least 50% increase) was of prognostic relevance. At 72-hours post-TAVI, 36.2% of the patients matched these VARC-II criteria of myocardial damage. However, these patients did not display a difference in survival compared to patients without significant myocardial injury.

CONCLUSION

Elevated preprocedural hsTNT represents an independent risk predictor of all-cause death while periprocedural hsTNT elevation failed to show prognostic relevance.

Heart failure 2016: still more questions than answers

Heart failure has reached epidemic proportions given the ageing of populations and is associated with high mortality and re-hospitalization rates. This article reviews and summarizes recent advances in the diagnosis, assessment and treatment of the patients with heart failure. Data are discussed based also on the most recent guidelines indications. Open issues and unmet needs are highlighted.