Long-Term Prognostic Value of High-Sensitivity Troponin T Added to N-Terminal Pro Brain Natriuretic Peptide Plasma Levels Before Valve Replacement for Severe Aortic Stenosis

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.

Impact of route of access and stenosis subtype on outcome after transcatheter aortic valve replacement

Introduction

Previous analyses have reported the outcomes of transcatheter aortic valve replacement (TAVR) for patients with low-flow, low-gradient (LFLG) aortic stenosis (AS), without stratifying according to the route of access. Differences in mortality rates among access routes have been established for high-gradient (HG) patients and hypothesized to be even more pronounced in LFLG AS patients. This study aims to compare the outcomes of patients with LFLG or HG AS following transfemoral (TF) or transapical (TA) TAVR.

Methods

A total of 910 patients, who underwent either TF or TA TAVR with a median follow-up of 2.22 (IQR: 1.22-4.03) years, were included in this multicenter cohort study. In total, 146 patients (16.04%) suffered from LFLG AS. The patients with HG and LFLG AS were stratified according to the route of access and compared statistically.

Results

The operative mortality rates of patients with HG and LFLG were found to be comparable following TF access. The operative mortality rate was significantly increased for patients who underwent TA access [odds ratio (OR): 2.91 (1.54-5.48), p = 0.001] and patients with LFLG AS [OR: 2.27 (1.13-4.56), p = 0.02], which could be corroborated in a propensity score-matched subanalysis. The observed increase in the risk of operative mortality demonstrated an additive effect [OR for TA LFLG: 5.45 (2.35-12.62), p < 0.001]. LFLG patients who underwent TA access had significantly higher operative mortality rates (17.78%) compared with TF LFLG (3.96%, p = 0.016) and TA HG patients (6.36%, p = 0.024).

Conclusions

HG patients experienced a twofold increase in operative mortality rates following TA compared with TF access, while LFLG patients had a fivefold increase in operative mortality rates. TA TAVR appears suboptimal for patients with LFLG AS. Prospective studies should be conducted to evaluate alternative options in cases where TF is not possible.

Multimodality imaging methods and systemic biomarkers in classical low-flow low-gradient aortic stenosis: Key findings for risk stratification

Objectives

The aim of the present study is to assess multimodality imaging findings according to systemic biomarkers, high-sensitivity troponin I (hsTnI) and B-type natriuretic peptide (BNP) levels, in low-flow, low-gradient aortic stenosis (LFLG-AS).

Background

Elevated levels of BNP and hsTnI have been related with poor prognosis in patients with LFLG-AS.

Methods

Prospective study with LFLG-AS patients that underwent hsTnI, BNP, coronary angiography, cardiac magnetic resonance (CMR) with T1 mapping, echocardiogram and dobutamine stress echocardiogram. Patients were divided into 3 groups according to BNP and hsTnI levels: Group 1 (n = 17) when BNP and hsTnI levels were below median [BNP < 1.98 fold upper reference limit (URL) and hsTnI < 1.8 fold URL]; Group 2 (n = 14) when BNP or hsTnI were higher than median; and Group 3 (n = 18) when both hsTnI and BNP were higher than median.

Results

49 patients included in 3 groups. Clinical characteristics (including risk scores) were similar among groups. Group 3 patients had lower valvuloarterial impedance (P = 0.03) and lower left ventricular ejection fraction (P = 0.02) by echocardiogram. CMR identified a progressive increase of right and left ventricular chamber from Group 1 to Group 3, and worsening of left ventricular ejection fraction (EF) (40 [31-47] vs. 32 [29-41] vs. 26 [19-33]%; p < 0.01) and right ventricular EF (62 [53-69] vs. 51 [35-63] vs. 30 [24-46]%; p < 0.01). Besides, there was a marked increase in myocardial fibrosis assessed by extracellular volume fraction (ECV) (28.4 [24.8-30.7] vs. 28.2 [26.9-34.5] vs. 31.8 [28.9-35.5]%; p = 0.03) and indexed ECV (iECV) (28.7 [21.2-39.1] vs. 28.8 [25.4-39.9] vs. 44.2 [36.4-51.2] ml/m², respectively; p < 0.01) from Group 1 to Group 3.

Conclusions

Higher levels of BNP and hsTnI in LFLG-AS patients are associated with worse multi-modality evidence of cardiac remodeling and fibrosis.

Novel predictive role for mid-regional proadrenomedullin in moderate to severe aortic stenosis

OBJECTIVE

We investigated the prognostic significance of selected known and novel circulating biomarkers in aortic stenosis (AS).

METHODS

N-terminal pro-BNP (NT-proBNP), high-sensitivity troponin-T (hsTnT), growth differentiation factor-15 (GDF-15), suppression of tumorigenicity-2 (ST2), mid-regional proadrenomedullin (MR-proADM) and mid-regional proatrial natriuretic peptide (MR-proANP) were measured in patients with moderate to severe AS, New York Heart Association (NYHA) class I-II and left ventricular ejection fraction ≥50%, recruited consecutively across five centres from 2011 to 2018. Their ability to predict both primary (all-cause mortality, heart failure hospitalisation or progression to NYHA class III-IV) and secondary (additionally incorporating syncope and acute coronary syndrome) outcomes was determined by competing risk analyses.

RESULTS

Among 173 patients with AS (age 69±11 years, 55% male, peak transaortic velocity (Vmax) 4.0±0.8 m/s), the primary and secondary outcomes occurred in 59 (34%) and 66 (38%), respectively. With aortic valve replacement as a competing risk, the primary outcome was determined consistently by the comorbidity index and each selected biomarker except ST2 (p<0.05), independent of NYHA class, Vmax, LV-global longitudinal strain and serum creatinine. MR-proADM had the highest discriminative value for both primary (subdistribution HR (SHR) 11.3, 95% CI 3.9 to 32.7) and secondary outcomes (SHR 12.6, 95% CI 4.7 to 33.5). Prognostic assessment of dual-biomarker combinations identified MR-proADM plus either hsTnT or NT-proBNP as the best predictive model for both clinical outcomes. Paired biomarker models were not superior to those including MR-proADM as the sole circulating biomarker.

CONCLUSION

MR-proADM most powerfully portended worse prognosis and should be further assessed as possibly the biomarker of choice for risk stratification in AS.

Watchful waiting care or early intervention in asymptomatic severe aortic stenosis: Where we are

Aortic stenosis, the most common valvular heart disease in Western countries, affects predominantly older people. Prompt aortic valve replacement is undoubtedly indicated in symptomatic patients. Management of asymptomatic patients is nowadays shifting from a conservative approach to early aortic valve replacement, as multimodality imaging is increasingly available. However, multimodality imaging has led to multiple prognostic parameters and complex algorithms, as well as a new staging classification that has left patients and physicians somewhat puzzled. We highlight the value of thorough serial clinical examinations, Doppler echocardiography and exercise testing when caring for a growing aortic stenosis population, including that has no or limited access to multimodality imaging. Evidence for early aortic valve replacement versus conservative management in asymptomatic patients with severe aortic stenosis is biased by the lack of serial stress testing evaluation; 30% of so-called asymptomatic patients were in fact symptomatic, and thus were clear candidates for aortic valve replacement in the above-mentioned studies. Randomized trials of aortic valve replacement versus conservative management that include serial stress testing evaluation are needed to ascertain whether early aortic valve replacement actually improves clinical outcome in asymptomatic patients with severe aortic stenosis. Less interventional medicine and healthcare resource utilization can result in better health.

Dataset on the prognostic value of cardiac biomarkers used in clinical routine in patients with severe aortic stenosis undergoing valve replacement

Hereby, the supplemental data of the research article “Long-Term Prognostic Value of High-Sensitivity Troponin T added to N-Terminal Pro Brain Natriuretic Peptide Plasma Levels before Valve Replacement for Severe Aortic Stenosis” are presented [1]. It offers enhanced input on the predictive value of these biomarkers considering the influence of the presence of concomitant coronary artery disease (CAD) in various severities as well as an additional cox proportional hazard model on cardiovascular mortality. Furthermore, the receiver operating characteristic (ROC) curves are shown as figures. The material described increases therefore the understanding of the predictive value of these already routinely available biomarkers and reduces the risk of potential bias due to possible confounding factors. It also underlines the urge for a multi-factorial approach in diagnostics to detect the optimal point for referral to valve replacement other than just symptomatic status, an observed reduction in left ventricular ejection fraction or the presence of CAD with the necessity for coronary artery bypass grafting (CABG) [2]. The data of the 3595 patients were gathered retrospectively at a consortium of four university hospital centers in Austria and combined with prospectively collected data on cardiovascular and all-cause mortality.