Prognostic usefulness of circulating high-sensitivity troponin T in aortic stenosis and relation to echocardiographic indexes of cardiac function and anatomy

Acute Coronary Syndrome Subphenotypes Based on Repeated Biomarker Measurements in Relation to Long-Term Mortality Risk

BACKGROUND

We aimed to identify patients with subphenotypes of postacute coronary syndrome (ACS) using repeated measurements of high-sensitivity cardiac troponin T, N-terminal pro-B-type natriuretic peptide, high-sensitivity C-reactive protein, and growth differentiation factor 15 in the year after the index admission, and to investigate their association with long-term mortality risk.

METHODS AND RESULTS

BIOMArCS (BIOMarker Study to Identify the Acute Risk of a Coronary Syndrome) was an observational study of patients with ACS, who underwent high-frequency blood sampling for 1 year. Biomarkers were measured in a median of 16 repeated samples per individual. Cluster analysis was performed to identify biomarker-based subphenotypes in 723 patients without a repeat ACS in the first year. Patients with a repeat ACS (N=36) were considered a separate cluster. Differences in all-cause death were evaluated using accelerated failure time models (median follow-up, 9.1 years; 141 deaths). Three biomarker-based clusters were identified: cluster 1 showed low and stable biomarker concentrations, cluster 2 had elevated concentrations that subsequently decreased, and cluster 3 showed persistently elevated concentrations. The temporal biomarker patterns of patients in cluster 3 were similar to those with a repeat ACS during the first year. Clusters 1 and 2 had a similar and favorable long-term mortality risk. Cluster 3 had the highest mortality risk. The adjusted survival time ratio was 0.64 (95% CI, 0.44-0.93; P=0.018) compared with cluster 1, and 0.71 (95% CI, 0.39-1.32; P=0.281) compared with patients with a repeat ACS.

CONCLUSIONS

Patients with subphenotypes of post-ACS with different all-cause mortality risks during long-term follow-up can be identified on the basis of repeatedly measured cardiovascular biomarkers. Patients with persistently elevated biomarkers have the worst outcomes, regardless of whether they experienced a repeat ACS in the first year.

Cardiac Troponin T and NT-proBNP for Prediction of 30-Day Readmission or Death in Patients with Acute Dyspnea: Data from the Akershus Cardiac Examination 2 Study

INTRODUCTION

N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT) measurements are recommended in patients with acute dyspnea. We aimed to assess the prognostic merit of cTnT compared to NT-proBNP for 30-day readmission or death in patients hospitalized with acute dyspnea.

METHODS

We measured cTnT and NT-proBNP within 24 h in 314 patients hospitalized with acute dyspnea and adjudicated the cause of the index admission. Time to first event of readmission or death ≤30 days after hospital discharge was recorded, and cTnT and NT-proBNP measurements were compared head-to-head.

RESULTS

Patients who died (12/314) or were readmitted (71/314) within 30 days had higher cTnT concentrations (median: 32.6, Q1-Q3: 18.4-74.2 ng/L vs. median: 19.4, Q1-Q3: 8.4-36.1 ng/L; p for comparison <0.001) and NT-proBNP concentrations (median: 1,753.6, Q1-Q3: 464.2-6,862.0 ng/L vs. median 984, Q1-Q3 201-3,600 ng/L; for comparison p = 0.027) compared to patients who survived and were not readmitted. cTnT concentrations were associated with readmission or death within 30 days after discharge both in the total cohort (adjusted hazard ratio [aHR]: 1.64, 95% confidence interval [CI]: 1.30-2.05) and in patients with heart failure (HF) (aHR: 1.58, 95% CI: 1.14-2.18). In contrast, NT-proBNP concentrations were not associated with short-term events, neither in the total cohort (aHR: 1.10, 95% CI: 0.94-1.30) nor in patients with adjudicated HF (aHR: 1.06, 95% CI: 0.80-1.40).

CONCLUSION

cTnT concentrations are associated with 30-day readmission or death in patients hospitalized with acute dyspnea, as well as in patients adjudicated HF.

Aortic Valvular Stenosis and Heart Failure: Advances in Diagnostic, Management, and Intervention

Up to 30% of patients with aortic stenosis (AS) present with heart failure (HF) symptoms with either reduced or preserved left ventricular ejection fraction. Many of these patients present with a low-flow state, reduced aortic-valve-area (≤1.0 cm²) with low aortic-mean-gradient and aortic-peak-velocity (<40 mm Hg and <4.0 m/s). Thus, determination of true severity is essential for correct management, and multi-imaging evaluation must be performed. Medical treatment of HF is imperative and should be optimized concurrently with the determination of AS-severity. Finally, AS should be treated according to guidelines, keeping in mind that HF and low-flow increase interventions risks.

Association of high-sensitivity troponin T with outcomes in asymptomatic non-severe aortic stenosis: a post-hoc substudy of the SEAS trial

BACKGROUND

High-sensitivity Troponin T (hsTnT), a biomarker of cardiomyocyte overload and injury, relates to aortic valve replacement (AVR) and mortality in severe aortic stenosis (AS). However, its prognostic value remains unknown in asymptomatic patients with AS. We aimed to investigate if an hsTnT level >14 pg/mL (above upper limit of normal 99th percentile) is associated with echocardiographic AS-severity, subsequent AVR, ischaemic coronary events (ICE), and mortality in asymptomatic patients with non-severe AS.

METHODS

In this post-hoc sub-analysis of the multicentre, randomised, double-blind, placebo-controlled SEAS trial (ClinicalTrials.gov, NCT00092677), we included asymptomatic patients with mild to moderate-severe AS. We ascertained baseline and 1-year hsTnT concentrations and examined the association between baseline levels and the risk of the primary composite endpoint, defined as the first event of all-cause mortality, isolated AVR (without coronary artery bypass grafting (CABG)), or ICE. Multivariable regressions and competing risk analyses examined associations of hsTnT level >14 pg/mL with clinical correlates and 5-year risk of the primary endpoint.

FINDINGS

Between January 6, 2003, and March 4, 2004, a total of 1873 patients were enrolled in the SEAS trial, and 1739 patients were included in this post-hoc sub-analysis. Patients had a mean (SD) age of 67.5 (9.7) years, 61.0% (1061) were men, 17.4% (302) had moderate-severe AS, and 26.0% (453) had hsTnT level >14 pg/mL. The median hsTnT difference from baseline to 1-year was 0.8 pg/mL (IQR, -0.4 to 2.3). In adjusted linear regression, log(hsTnT) did not correlate with echocardiographic AS severity (p = 0.36). In multivariable Cox regression, a hsTnT level >14 pg/mL vs. hsTnT ≤14 pg/mL was associated with an increased risk of the primary composite endpoint (HR, 1.41; 95% CI, 1.18-1.70; p = 0.0002). In a competing risk model of first of the individual components of the primary endpoint, a hsTnT level >14 pg/mL was associated with ICE risk (HR 1.71; 95% CI, 1.23-2.38; p = 0.0013), but not with isolated AVR (p = 0.064) or all-cause mortality (p = 0.49) as the first event.

INTERPRETATION

hsTnT level is within the reference range (≤14 pg/mL) in 3 out of 4 non-ischaemic patients with asymptomatic mild-to-moderate AS and remains stable during a 1-year follow-up regardless of AS-severity. An hsTnT level >14 pg/mL was mainly associated with subsequent ICE, which suggest that hsTnT concentration is primarily a risk marker of subclinical coronary atherosclerotic disease.

FUNDING

Merck & Co., Inc., the Schering-Plough Corporation, the Interreg IVA program, Roche Diagnostics Ltd., and Gangstedfonden. Open access publication fee funding provided by prof. Olav W. Nielsen and Department of Cardiology, Bispebjerg University Hospital, Denmark.

Prognostic role of pre- and postinterventional myocardial injury in patients undergoing transcatheter aortic valve implantation

BACKGROUND

Chronic pre-procedural and acute post-procedural myocardial injury are frequently observed in patients with aortic stenosis undergoing transcatheter aortic valve implantation (TAVI). The aim of our study was to investigate the prognostic role of high sensitivity cardiac troponins (hs-cTns) elevation before and after TAVI.

METHODS

106 patients with severe aortic stenosis who underwent TAVI were enrolled. High sensitivity cardiac troponin T (hs-cTnT) was measured before and after TAVI (6, 24, 48, 72 hours). Post-procedural myocardial damage was defined as a 15-fold rise in hs-cTnT upper reference limit (URL) after TAVI. The clinical endpoints were all cause death, cardiovascular death and re-hospitalization at 24 months follow-up.

RESULTS

Before TAVI, hs-cTnT median value was 0.03 μg/L (2.3±2.1 fold over URL). After TAVI procedure, myocardial damage (MD), as defined by VARC-2 criteria, was observed in 40 patients (38%) (MD group). In our population, logarithmically transformed hs-cTnTs were independently associated with all-cause mortality at 24 months F/U (pre-TAVI hs-cTnT: Hazard ratio [HR] 2.2, 95% confidence interval [CI]: 1.1 to 4.4, P=0.027). No significant differences were observed between the MD and non-MD groups for the three endpoints of all cause death (p log rank: 0.15), cardiovascular death (p log rank: 0.86) and re-hospitalization (p log rank: 0.87).

CONCLUSIONS

Only baseline hs-cTnT levels correlated with outcomes at 24 months of follow-up. Chronic pre-procedural myocardial injury significantly affects prognosis after TAVI.

Associations between cardiovascular risk factors, biomarkers, and left ventricular mechanical dispersion: insights from the ACE 1950 Study

Aims

Mechanical dispersion measures left ventricular contraction heterogeneity and is associated with the risk of sudden cardiac death. However, the associations between mechanical dispersion and cardiovascular risk factors in early mid-life, and established biomarkers of sub-clinical myocardial injury and dysfunction are not known. We aimed to examine this in the general population.

Methods and results

During 2012–15, we included 2527 Norwegian individuals from the general population born in 1950, with measurements of mechanical dispersion by 2D speckle tracking echocardiography and concentrations of high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) available. Mechanical dispersion was calculated as the standard deviation of the contraction duration of 17 strain segments. We assessed the associations between mechanical dispersion, concentrations of hs-cTnT and NT-proBNP, and cardiovascular risk factors collected at a national health screening survey two decades earlier. At echocardiography baseline, median age was 64 (interquartile range 63.5–64.5) years, 49.8% were women, 59.1% had hypertension, and 5.9% reported established coronary artery disease. Median mechanical dispersion was 38.0 (29.5–47.0) ms, median hs-cTnT concentration 6 (4–8) ng/L, and the median NT-proBNP concentration 54 (34–93) ng/L. Mechanical dispersion was associated with both hs-cTnT and NT-proBNP concentrations in multivariable models adjusted for clinical and echocardiographic variables. High body mass index, serum triglyceride concentrations, and low resting heart rate at Age 40 were independently associated with increased mechanical dispersion two decades later.

Conclusion

Established risk factors at Age 40 are associated with mechanical dispersion two decades later, and mechanical dispersion is cross-sectionally associated with biomarkers of subclinical myocardial injury and dysfunction.

Elevated high-sensitivity troponin T levels at 1-year follow-up are associated with increased long-term mortality after TAVR

BACKGROUND

Elevated pre-procedural high-sensitivity troponin T (hs-TnT) levels predict adverse outcomes in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). It is unknown whether elevated troponin levels still provide prognostic information during follow-up after successful TAVR. We evaluated the long-term implications of elevated hs-TnT levels found at 1-year post-TAVR.

METHODS AND RESULTS

The study included 349 patients who underwent TAVR for severe AS from 2010-2019 and for whom 1-year hs-TnT levels were available. Any required percutaneous coronary interventions were performed > 1 week before TAVR. The primary endpoint was survival time starting at 1-year post-TAVR. Optimal hs-TnT cutoff for stratifying risk, identified by ROC analysis, was 39.4 pg/mL. 292 patients had hs-TnT < 39.4 pg/mL (median 18.3 pg/mL) and 57 had hs-TnT ≥ 39.4 pg/mL (median 51.2 pg/mL). The high hs-TnT group had a higher median N-terminal pro-B-type natriuretic peptide (NT-proBNP) level, greater left ventricular (LV) mass, higher prevalence of severe diastolic dysfunction, LV ejection fraction < 35%, severe renal dysfunction, and more men compared with the low hs-TnT group. All-cause mortality during follow-up after TAVR was significantly higher among patients who had hs-TnT ≥ 39.4 pg/mL compared with those who did not (mortality rate at 2 years post-TAVR: 12.3% vs. 4.1%, p = 0.010). Multivariate analysis identified 1-year hs-TnT ≥ 39.4 pg/mL (hazard ratio 2.93, 95% CI 1.91-4.49, p < 0.001), NT-proBNP level > 300 pg/mL, male sex, an eGFR < 60 mL/min/1.73 m2 and chronic obstructive pulmonary disease as independent risk factors for long-term mortality after TAVR.

CONCLUSIONS

Elevated hs-TnT concentrations at 1-year after TAVR were associated with a higher long-term mortality.

High-sensitivity cardiac troponin T and N-terminal pro-B-type natriuretic peptide in acute heart failure: Data from the ACE 2 study

BACKGROUND

To assess if cardiac troponins can improve diagnostics of acute heart failure (AHF) and provide prognostic information in patients with acute dyspnea.

METHODS

We measured cardiac troponin T with a high-sensitivity assay (hs-cTnT) in 314 patients hospitalized with acute dyspnea. The index diagnosis was adjudicated and AHF patients were stratified into AHF with reduced or preserved ejection fraction (HFrEF/HFpEF). The prognostic and diagnostic merit of hs-cTnT was compared to the merit of N-terminal pro-B-type natriuretic peptide (NT-proBNP).

RESULTS

In the total population, median age was 73 (quartile [Q] 1-3 63-81) years and 48% were women. One-hundred-forty-three patients were categorized as AHF (46%) and these patients had higher hs-cTnT concentrations than patients with non-AHF-related dyspnea: median 38 (Q1-3 22-75) vs. 13 (4-25) ng/L; p < 0.001. hs-cTnT concentrations were similar between patients with HFrEF and HFpEF (p = 0.80), in contrast to NT-proBNP, which was higher in HFrEF (p < 0.001). C-statistics for discriminating HFpEF from non-AHF-related dyspnea was 0.80 (95% CI 0.73-0.86) for hs-cTnT, 0.79 (0.73-0.86) for NT-proBNP, and 0.83 (0.76-0.89) for hs-cTnT and NT-proBNP in combination. Elevated hs-cTnT remained associated with HFpEF in logistic regression analysis after adjusting for demographics, comorbidities and renal function. During median 27 months of follow-up, 114 (36%) patients died in the total population. Higher hs-cTnT concentrations were associated with increased risk of all-cause mortality after adjustment for clinical variables and NT-proBNP: hazard ratio 1.30 (95% CI 1.07-1.58), p = 0.009.

CONCLUSION

hs-cTnT measurements improve diagnostic accuracy for HFpEF and provide independent prognostic information in unselected patients with acute dyspnea.

Is the true clinical value of high-sensitivity troponins as a biomarker of risk? The concept that detection of high-sensitivity troponin 'never means nothing'

INTRODUCTION

High-sensitivity troponin (hs-cTn) assays are central to the diagnosis of myocardial infarction (MI). Their increased sensitivity has facilitated rapid pathways for the exclusion of MI. However, hs-cTn is now more readily detectable in patients without symptoms typical of MI, in whom a degree of myocardial injury is assumed. Recently, the practice of using the 99^th centile of hs-cTn as a working 'upper reference limit' has been challenged. There is increasing evidence that hs-cTn may provide useful prognostic information, regardless of any suspicion of MI, and as such these assays may have potential as a general biomarker for mortality. This raises the concept that detection of hs-cTn 'never means nothing.'

AREAS COVERED

In this review, we will evaluate the evidence for the use of hs-cTn assays outside their common clinical indication to rule out or diagnose acute MI.

EXPERT OPINION

The data presented suggest that hs-cTn testing may in the future have a generalized role as a biomarker of mortality risk and may be used less as a test for ruling in acute MI, but will remain a frontline test to exclude that diagnosis in ED. Further, the data suggest that the detection of hs-cTn 'never means nothing.'

Cardiac troponin is associated with cardiac outcomes in men and women with atrial fibrillation, insights from the ARISTOTLE trial

BACKGROUND

Cardiac troponin T (cTnT) and I (cTnI) concentrations provide strong prognostic information in anticoagulated patients with atrial fibrillation (AF). Whether the associations between cardiac troponin concentrations and mortality and morbidity differ by sex is not known.

OBJECTIVES

To assess whether men and women have different concentrations and prognostic value of cTnT and cTnI measurements in anticoagulated patients with AF.

METHODS

cTnT and cTnI concentrations were measured with high-sensitivity (hs) assays in EDTA plasma samples obtained from the multicentre ARISTOTLE trial, which randomized patients with AF and at least one risk factor for stroke or systemic embolic event to warfarin or apixaban. Patients were stratified according to sex and the associations between hs-troponin concentrations, and all-cause death, cardiac death, myocardial infarction, stroke or systemic embolic event and major bleeding were assessed in multivariable regression models.

RESULTS

We found higher cardiac troponin concentrations in men (n = 9649) compared to women (n = 5331), both for hs-cTnT (median 11.8 [Q1-3 8.1-18.0] vs. 9.6 [6.7-14.3] ng L^-1 , P < 0.001) and hs-cTnI (5.8 [3.4-10.8] vs. 4.9 [3.1-8.8] ng L^-1 , P < 0.001). Adjusting for baseline demographics, comorbidities and medications, men still had significantly higher hs-troponin concentrations than women. C-reactive protein and N-terminal pro-B-type natriuretic peptide concentrations were higher in female patients. Both hs-cTnT and hs-cTnI concentrations were associated with all clinical outcomes similarly in men and women (p-value for interaction >0.05 for all end-points).

CONCLUSION

Men have higher hs-troponin concentrations than women in AF. Regardless of sex, hs-troponin concentrations remain similarly associated with adverse clinical outcomes in anticoagulated patients with AF.

Patient Management in Aortic Stenosis: Towards Precision Medicine Through Protein Analysis, Imaging and Diagnostic Tests

Aortic stenosis is the most frequent valvular disease in developed countries. It progresses from mild fibrocalcific leaflet changes to a more severe leaflet calcification at the end stages of the disease. Unfortunately, symptoms of aortic stenosis are unspecific and only appear when it is too late, complicating patients' management. The global impact of aortic stenosis is increasing due to the growing elderly population. The disease supposes a great challenge because of the multiple comorbidities of these patients. Nowadays, the only effective treatment is valve replacement, which has a high cost in both social and economic terms. For that reason, it is crucial to find potential diagnostic, prognostic and therapeutic indicators that could help us to detect this disease in its earliest stages. In this article, we comprehensively review several key observations and translational studies related to protein markers that are promising for being implemented in the clinical field as well as a discussion about the role of precision medicine in aortic stenosis.

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.

Myocardial Injury in the Era of High-Sensitivity Cardiac Troponin Assays: A Practical Approach for Clinicians

Importance

Traditionally, elevated troponin concentrations were synonymous with myocardial infarction. But with improvements in troponin assays, elevated concentrations without overt myocardial ischemia are now more common; this is referred to as myocardial injury. Physicians may be falsely reassured by the absence of myocardial ischemia; however, recent evidence suggests that myocardial injury is associated with even more detrimental outcomes. Accordingly, this article reviews the definition, epidemiology, differential diagnosis, diagnostic evaluation, and management of myocardial injury.

Observations

Current epidemiological evidence suggests that myocardial injury without overt ischemia represents about 60% of cases of abnormal troponin concentrations when obtained for clinical indications, and 1 in 8 patients presenting to the hospital will have evidence of myocardial injury. Myocardial injury is a concerning prognosis; the 5-year mortality rate is approximately 70%, with a major adverse cardiovascular event rate of 30% in the same period. The differential diagnosis is broad and can be divided into acute and chronic precipitants. The initial workup involves an assessment for myocardial ischemia. If infarction is ruled out, further evaluation includes a detailed history, physical examination, laboratory testing, a 12-lead electrocardiogram, and (if there is no known history of structural or valvular heart disease) an echocardiogram. Unfortunately, no consensus exists on routine management of patients with myocardial injury. Identifying and treating the underlying precipitant is the most practical approach.

Conclusion and Relevance

Myocardial injury is the most common cause of abnormal troponin results, and its incidence will likely increase with an aging population, increasing prevalence of cardiovascular comorbidities, and greater sensitivity of troponin assays. Myocardial injury represents a challenge to clinicians; however, given its serious prognosis, it warrants a thorough evaluation of its underlying precipitant. Future strategies to prevent and/or manage myocardial injury are needed.

Cardiac Troponin I and T Are Associated with Left Ventricular Function and Structure: Data from the Akershus Cardiac Examination 1950 Study

Background

Concentrations of cardiac troponin I (cTnI) and T (cTnT) are associated with clinical cardiac outcomes, but do not correlate closely in subjects recruited from the general population. Accordingly, we hypothesized that cTnI and cTnT concentrations would be influenced by different cardiovascular (CV) and non-CV risk factors and reflect different CV phenotypes.

Methods

We measured cTnI and cTnT with last generation assays in 1236 women and 1157 men with no known CV disease participating in the prospective observational Akershus Cardiac Examination 1950 Study. All study participants underwent extensive CV phenotyping at baseline, including detailed echocardiography.

Results

Concentrations of cTnI were measurable in 60.3% and cTnT in 72.5% of study participants (P &lt; 0.001), and correlated moderately (r = 0.53; P &lt; 0.001). cTnI was more strongly associated with male sex (P = 0.018), higher education (P &lt; 0.001), history of hypertension (P &lt; 0.001), and age (P &lt; 0.001), whereas cTnT was more strongly associated with eGFR (P = 0.015). Both cTnI and cTnT were inversely associated with global longitudinal strain and positively associated with LV mass index (LVMI) in analyses adjusted for CV risk factors. The association between cTnI and LVMI was stronger than the association between cTnT and LVMI (P = 0.035). Concentrations of cTnI improved diagnostic accuracy for LV hypertrophy when added to established CV risk factors, but concentrations of cTnT did not improve these models further.

Conclusions

In a large community-based cohort examined with extensive echocardiography, concentrations of cTnI and cTnT are associated with subclinical LV hypertrophy and dysfunction. Concentrations of cTnI appear superior to cTnT in predicting subclinical LV hypertrophy.

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

Natriuretic peptide plasma levels help to manage patients with severe aortic stenosis (AS). The role of troponin plasma levels in this patient cohort remains speculative. A consortium of 4 university hospital centers in Austria analyzed retrospectively 3,595 patients admitted for valve replacement because of severe AS since 2007. The aim was to compare the additive preprocedural value of high-sensitivity troponin T (hsTnT) to N-terminal pro brain natriuretic peptide (NT-proBNP) plasma levels in predicting postoperative long-term survival in a large cohort undergoing either surgical (57.8%) or transcatheter (42.2%) aortic valve replacement. During a median follow-up of 2.93 (1.91 to 4.92) years, 919 patients (25.6%) died, in them 556 (15.5%) due to cardiovascular causes. Both normal hsTnT (<14 ng/l) and NT-proBNP (within age- and sex-corrected normal range) plasma levels were found in 481 patients (14.3%, group 1). Normal hsTnT but elevated NT-proBNP plasma levels were found in 748 patients (22.3%, group 2). Elevated hsTnT but normal NT-proBNP plasma levels were found in 258 patients (7.7%, group 3). Both elevated hsTnT and elevated NT-proBNP plasma levels were found in 1,869 patients (55.7%, group 4). Using Log Rank tests for comparison there was a highly significant difference in both cardiovascular mortality (p <0.0001) and all-cause mortality (p <0.0001). All-cause mortality rates after 1, 3, and 5 years were 2.1%, 5.4%, 7.7% in group 1; 4.0%, 7.5%, 11.5% in group 2; 5.8%, 8.9%, 14.0% in group 3; and 12.3%, 22.6%, 28.4% in group 4. In conclusion, hsTnT adds additional impact to NT-proBNP as a routinely available biomarker for risk stratification concerning postoperative survival in patients with severe AS admitted for valve replacement. The present study supports the concept to integrate hsTnT plasma levels in the management of severe AS.

Circulating secretoneurin concentrations in patients with moderate to severe aortic stenosis

BACKGROUND

Secretoneurin (SN) concentrations provide important prognostic information in patients with myocardial dysfunction. Whether preoperative SN concentrations improve risk assessment in patients with moderate to severe aortic stenosis (AS) is unknown.

METHODS

We included 57 patients with moderate to severe AS referred for presurgical evaluation. All patients were examined with comprehensive echocardiography, electrocardiogram (ECG), and biochemical measurements and compared to 10 age- and sex-matched healthy subjects.

RESULTS

Median (quartile 1-3) SN concentrations were 141 (121-163) pmol/L in AS patients and 132 (106-148) pmol/L in control subjects (p = .17). Lower estimated creatinine clearance and use of diuretics, but not standard ECG or echocardiographic indices and cardiac biomarkers, were associated with increasing SN concentrations. Fifteen patients (26%) died during 3.5 years median follow-up. SN concentrations were higher in non-survivors than survivors: 156 (133-209) vs. 140 (116-155) pmol/L, p = .007. Higher SN concentrations were associated with increased risk of mortality also after adjustment for established risk indices, biomarkers, and status regarding valvular surgery: hazard ratio per _lnSN 15.13 (95% CI 1.05-219.00); p = .046. Receiver operating characteristics area under the curve for SN to predict mortality was 0.74 (95% CI 0.60-0.88) compared to 0.73 (0.59-0.87) for high-sensitivity cardiac troponin T and 0.67 (0.51-0.82) for N-terminal pro-B-type natriuretic peptide. The previously identified cut-off of SN >204 pmol/L in cardiac surgical patients predicted mortality also in this cohort.

CONCLUSIONS

SN concentrations improve risk assessment in patients with moderate to severe AS by providing additional prognostic information to established risk indices such as echocardiography, ECG, and established cardiac biomarkers.

Biological variation of cardiac markers in patients with aortic valve stenosis

Objective

Cardiac biomarkers hold promise for follow-up and management of aortic valve stenosis (AVS). When interpreting serial biomarker measurements of patients with AVS, it can be challenging to distinguish ‘real changes’ from ‘random fluctuation’. Hence, robust estimation of the biological variation of these biomarkers is essential. In the present study we assessed biological variation of B-type natriuretic peptide (BNP), N-terminus pro-brain natriuretic peptide (NT-proBNP), high-sensitivity troponin-T and high-sensitivity troponin-I (hs-TnT and hs-TnI), and ST2 in subjects with stable AVS.

Methods

Serial blood sampling was performed in 25 subjects with moderate AVS—confirmed by echocardiography—and all free from acute cardiovascular events in the past 6 months. Blood samples were taken on seven standardised occasions during 1 year. Analytical variation (CV_A), within-subject biological variation (CV_I), between-subject biological variation (CV_G), index of individuality (II) and reference change values were calculated for all cardiac biomarkers.

Results

CV_I was highest for BNP (62.0%, 95% CI 52.5 to 75.4) and lowest for hs-TnI (9.2%, 95% CI 2.8 to 13.8). CV_G exceeded the CV_I for all biomarkers except BNP, and ranged from 19.8% (95% CI 13.8 to 33.4) for ST2 to 57.2% (95% CI 40.4 to 97.3) for hs-TnT. NT-proBNP, hs-TnT and ST2 revealed CV_A <5%, while BNP and hs-TnI showed a higher CV_A (19.7 and 14.9, respectively). All biomarkers except BNP showed marked individuality, with II ranging from 0.21 to 0.67 (BNP 1.34).

Conclusion

This study provides the first biological variation estimates of cardiac biomarkers in patients with stable AVS. These estimates allow a more evidence-based interpretation of biomarker changes in the follow-up and management of patients with AVS.

Trial registration number

NCT02510482

Prognostic Impact of Pre-Transcatheter and Post-Transcatheter Aortic Valve Intervention Troponin: A Large Cohort Study

Background Biomarkers were advocated as prognostic factors in patients undergoing transcatheter aortic valve intervention, with contradictory results concerning prognostic impact of troponin. Our aim was to assess the prognostic impact of preprocedural and postprocedural troponin in transcatheter aortic valve intervention. Methods and Results Preprocedural and postprocedural high-sensitivity troponin levels were measured in all patients undergoing transcatheter aortic valve intervention. Primary end point was 1-year mortality. This study included 1390 patients, with a mean age of 83.4±6.8 years. Patients were divided into 3 tertiles according to preprocedural troponin values: tertile 1: 0.001 to 0.023 μg/L; tertile 2: 0.024 to 1.80 μg/L; and T3: 1.81 to 12.1 μg/L. One-year mortality was higher in patients in tertile 2 (hazard ratio, 2.1; P=0.001) and T3 (hazard ratio, 1.8; P=0.009) compared with those in tertile 1. Myocardial injury was predictive of 1-year mortality (hazard ratio, 1.7; P=0.01). This effect may be stronger in the tertile 1 subgroup (hazard ratio, 5.1; P=0.03 [ P value for interaction: 0.18]). Conclusions Elevated preprocedural troponin and myocardial injury are associated with 1-year mortality after transcatheter aortic valve intervention.

High-sensitivity troponin T in asymptomatic severe aortic stenosis

Background: In asymptomatic severe aortic stenosis (ASAS), treatment decisions are made on an individual basis, and case management presents a clinical conundrum. Methods: We prospectively phenotyped consecutive patients with ASAS using echocardiography, exercise echocardiography, cardiac MRI and biomarkers (NT-proBNP, high-sensitivity troponin T (hs-TnT) and ST2) (n = 58). The primary endpoint was a composite of cardiovascular death, new-onset symptoms, cardiac hospitalization, guideline-driven indication for valve replacement and cardiovascular death at 12 months. Results: During the first year, 46.6% patients met primary endpoint. In multivariable analysis, aortic regurgitation ≥2 (p = 0.01) and hs-TnT (p = 0.007) were the only independent predictors of the primary endpoint. The best cutoff value was identified as hs-TnT >10ng/L, which was associated with a ∼10-fold greater risk of the primary endpoint (HR, 9.62; 95% CI, 2.27-40.8; p = 0.002). A baseline predictive model including age, sex and variables showing p < 0.10 in univariable analyses showed an area under the curve (AUC) of 0.79(0.66-0.91). Incorporation of hs-TnT into this model increased the AUC to 0.90(0.81-0.98) (p = 0.03). Patient reclassification with the model including hs-TnT yielded an NRI of 1.28(0.46-1.78), corresponding to 43% adequately reclassified patients. Conclusions: In patients with ASAS, hs-TnT >10ng/L was associated with high risk of events within 12 months. Including hs-TnT in routine ASAS management markedly improved prediction metrics.

Elevated High-Sensitivity Troponin I in the Stabilized Phase after an Acute Coronary Syndrome Predicts All-Cause and Cardiovascular Mortality in a Highly Admixed Population: A 7-Year Cohort

Background

High-sensitivity cardiac troponin I (hs-cTnI) has played an important role in the risk stratification of patients during the in-hospital phase of acute coronary syndrome (ACS), but few studies have determined its role as a long-term prognostic marker in the outpatient setting.

Objective

To investigate the association between levels of hs-cTnI measured in the subacute phase after an ACS event and long-term prognosis in a highly admixed population.

Methods

We measured levels of hs-cTnI in 525 patients 25 to 90 days after admission for an ACS event; these patients were then divided into tertiles according to hs-cTnI levels and followed for up to 7 years. We compared all-cause and cardiovascular mortality using Cox proportional hazards models and adopting a significance level of 5%.

Results

After a median follow-up of 51 months, patients in the highest tertile had a greater hazard ratio (HR) for all-cause mortality after adjustment for age, sex, known cardiovascular risk factors, medication use, and demographic factors (HR: 3.84, 95% CI: 1.92-8.12). These findings persisted after further adjustment for estimated glomerular filtration rate < 60 ml/min/1.73 m² and left ventricular ejection fraction < 0.40 (HR: 6.53, 95% CI: 2.12-20.14). Cardiovascular mortality was significantly higher in the highest tertile after adjustment for age and sex (HR: 5.65, 95% CI: 1.94-16.47) and both in the first (HR: 4.90, 95% CI: 1.35-17.82) and second models of multivariate adjustment (HR: 5.89, 95% CI: 1.08-32.27).

Conclusions

Elevated hs-cTnI levels measured in the stabilized phase after an ACS event are independent predictors of all-cause and cardiovascular mortality in a highly admixed population.

Clinical Relevance of Troponin T Profile Following Cardiac Surgery

Background: Peak post-operative cardiac troponin T (cTnT) independently predicts mid- and long-term outcome of cardiac surgery patients. A few studies however have reported two peaks of cTnT over the first 48–72 h following myocardial reperfusion. The aim of the current study was to better understand underlying reasons of these different cTnT profiles and their possible relevance in terms of clinical outcome.

Methods: All consecutive adult cardiac surgical procedures performed with an extra-corporeal circulation during a >6 years period were retrospectively evaluated. Patients with a myocardial infarction (MI) < 8 days were excluded. cTnT profile of patients with at least one value ≥1 ng/mL value were categorized according to the time occurrence of the peak value. Univariable and multivariable analysis were performed to identify factors influencing early vs. late increase of cTnT values, and to verify the correlation of early vs. late increase with clinical outcome.

Results: Data of 5,146 patients were retrieved from our prospectively managed registry. From 953 with at least one cTnT value ≥1 ng/mL, peak occurred ≤ 6 h (n = 22), >6 to ≤ 12 h (n = 366), >12 to ≤ 18 h (n = 176), >18 to ≤ 24 h (171), >24 h (218). Age (OR: 1.023; CI: 1.016–1.030) and isolated CABG (OR: 1.779; CI: 1.114–2.839) were independent predictors of a late increase of cTnT over a limit of 1 ng/ml (p < 0.05), whereas isolated valve procedures (OR: 0.685; CI: 0.471–0.998) and cross-clamp duration (OR: 0.993; CI: 0.990–0.997) independently predicted an early elevation (p < 0.05). Delayed elevation as opposed to early elevation correlated with a higher rate of post-operative complications including MI (19.8 vs. 7.2%), new renal insufficiency (16.3 vs. 6.7%), MACCE (32.0 vs. 15.5%), or death (7.4 vs. 4.4%).

Conclusion: Profile of cTnT elevation following cardiac surgery depends on patients' intrinsic factors, type of surgery and duration of cross-clamp time. Delayed increase is of higher clinically relevance than prompt post-operative elevation.

Clinical use of cardiac troponin for acute cardiac care and emerging opportunities in the outpatient setting

Cardiac troponin (cTn) testing has evolved significantly in recent times. Because of increased sensitivity, its use has shifted from a marker used to help diagnose acute myocardial infarction (MI) to a marker than can be used in the outpatient setting, as well as for both detection of myocardial injury and risk-stratification. Its main role remains in the diagnosis of acute MI and the risk-stratification of patients presenting with suspected acute coronary syndrome. The analytical improvements in assays leading to precise high-sensitivity cTn assays have contributed to the development of numerous strategies to identify patients at both low- and high-risk for acute MI within a few hours. These approaches should reduce overcrowding in the emergency room and expedite triaging. The ability of measuring cTn in most patients using high-sensitivity (hs) assays has allowed for the opportunity to examine its use in the detection of cardiotoxicity in patients undergoing chemotherapy, as well as exploring the application in both primary and secondary prevention of coronary artery disease. This particular field of research has become increasingly complex, partly due to the numerous cTn assays available (I and T; point-of-care, contemporary, hs) and an array of approaches in which one can use the test. The purpose of this document is to summarize the analytical and clinical information relevant to cTn assays, in particular, hs-cTn assays, and describe present and future opportunities for use of cTn in acute cardiac care and in the outpatient setting.

Cardiac Troponin T Concentrations, Reversible Myocardial Ischemia, and Indices of Left Ventricular Remodeling in Patients with Suspected Stable Angina Pectoris: a DOPPLER-CIP Substudy

BACKGROUND

Cardiac troponin T concentrations measured with high-sensitivity assays (hs-cTnT) provide important prognostic information for patients with stable coronary artery disease (CAD). However, whether hs-cTnT concentrations mainly reflect left ventricular (LV) remodeling or recurrent myocardial ischemia in this population is not known.

METHODS

We measured hs-cTnT concentrations in 619 subjects with suspected stable CAD in a prospectively designed multicenter study. We identified associations with indices of LV remodeling, as assessed by cardiac MRI and echocardiography, and evidence of myocardial ischemia diagnosed by single positron emission computed tomography.

RESULTS

Median hs-cTnT concentration was 7.8 ng/L (interquartile range, 4.8–11.6 ng/L), and 111 patients (18%) had hs-cTnT concentrations above the upper reference limit (&gt;14 ng/L). Patients with hs-cTnT &gt;14 ng/L had increased LV mass (144 ± 40 g vs 116 ± 34 g; P &lt; 0.001) and volume (179 ± 80 mL vs 158 ± 44 mL; P = 0.006), lower LV ejection fraction (LVEF) (59 ± 14 vs 62 ± 11; P = 0.006) and global longitudinal strain (14.1 ± 3.4% vs 16.9 ± 3.2%; P &lt; 0.001), and more reversible perfusion defects (P = 0.001) and reversible wall motion abnormalities (P = 0.008). Age (P = 0.009), estimated glomerular filtration rate (P = 0.01), LV mass (P = 0.003), LVEF (P = 0.03), and evidence of reversible myocardial ischemia (P = 0.004 for perfusion defects and P = 0.02 for LV wall motion) were all associated with increasing hs-cTnT concentrations in multivariate analysis. We found analogous results when using the revised US upper reference limit of 19 ng/L.

CONCLUSIONS

hs-cTnT concentrations reflect both LV mass and reversible myocardial ischemia in patients with suspected stable CAD.

Sex Dimorphism in the Myocardial Response to Aortic Stenosis

OBJECTIVES

The goal of this study was to explore sex differences in myocardial remodeling in aortic stenosis (AS) by using echocardiography, cardiac magnetic resonance (CMR), and biomarkers.

BACKGROUND

AS is a disease of both valve and left ventricle (LV). Sex differences in LV remodeling are reported in AS and may play a role in disease phenotyping.

METHODS

This study was a prospective assessment of patients awaiting surgical valve replacement for severe AS using echocardiography, the 6-min walking test, biomarkers (high-sensitivity troponin T and N-terminal pro-brain natriuretic peptide), and CMR with late gadolinium enhancement and extracellular volume fraction, which dichotomizes the myocardium into matrix and cell volumes. LV remodeling was categorized into normal geometry, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy.

RESULTS

In 168 patients (age 70 ± 10 years, 55% male, indexed aortic valve area 0.40 ± 0.13 cm2/m2, mean gradient 47 ± 4 mm Hg), no sex or age differences in AS severity or functional capacity (6-min walking test) were found. CMR captured sex dimorphism in LV remodeling not apparent by using 2-dimensional echocardiography. Normal geometry (82% female) and concentric remodeling (60% female) dominated in women; concentric hypertrophy (71% male) and eccentric hypertrophy (76% male) dominated in men. Men also had more evidence of LV decompensation (pleural effusions), lower left ventricular ejection fraction (67 ± 16% vs. 74 ± 13%; p < 0.001), and higher levels of N-terminal pro-brain natriuretic peptide (p = 0.04) and high-sensitivity troponin T (p = 0.01). Myocardial fibrosis was higher in men, with higher focal fibrosis (late gadolinium enhancement 16.5 ± 11.2 g vs. 10.5 ± 8.9 g; p < 0.001) and extracellular expansion (matrix volume 28.5 ± 8.8 ml/m2 vs. 21.4 ± 6.3 ml/m2; p < 0.001).

CONCLUSIONS

CMR revealed sex differences in associations between AS and myocardial remodeling not evident from echocardiography. Given equal valve severity, the myocardial response to AS seems more maladaptive in men than previously reported. (Regression of Myocardial Fibrosis After Aortic Valve Replacement [RELIEF-AS]; NCT02174471).

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.

Association of high-sensitivity cardiac troponin T with mortality and cardiovascular events in a community-based prospective study in Beijing

OBJECTIVE

The prognostic value of cardiac troponins in apparently healthy populations is not well established. The aim of this study was to investigate the prognostic properties of high-sensitivity cardiac troponin T (hs-cTnT) for long-term adverse outcomes.

SETTING

A community-dwelling prospective survey of residents from two communities in Beijing.

PARTICIPANTS

From September 2007 to January 2009, 1680 participants were initially enrolled. Of these, 1499 (870 females, mean age: 61.4 years) participants completed the survey and were followed up for a median of 4.8 years (IQR: 4.5-5.2).

OUTCOME MEASURES

The primary outcome was the occurrence of all-cause mortality and major cardiovascular events.

RESULTS

Overall, 820 individuals (54.7%) had detectable hs-cTnT levels. During the follow-up, 52 participants (3.5%) died, 154 (10.3%) had major cardiovascular events and 99 (6.6%) experienced new-onset coronary events. Compared with those with undetectable hs-cTnT levels, participants with hs-cTnT levels in the highest category (≥14 ng/L) had a significantly increased risk for all-cause mortality (adjusted HR (aHR): 2.07, 95% CI 1.05 to 3.01), major cardiovascular events (aHR: 3.27, 95% CI 1.88 to 5.70) and coronary events (aHR: 4.50, 95% CI 2.26 to 9.02) in covariate-adjusted analyses. No differences in stroke incidence were found (aHR: 1.27, 95% CI 0.69 to 2.62). Also, significant associations were presented when hs-cTnT levels were modelled as a continuous variable and when analysing changes in hs-cTnT levels over time with adverse outcomes. The addition of troponin T levels to clinical variables led to significant increases in risk prediction with a marked improvement in the C-statistics (p=0.003 or lower).

CONCLUSIONS

In this cohort of individuals from a community-based population, cTnT levels measured with a highly sensitive assay were associated with increases in the subsequent risk for all-cause mortality and major cardiovascular events. These results might support screening for at-risk individuals.

Changing concept in treatment of asymptomatic severe aortic stenosis and normal ejection fraction: time for biomarkers reappraisal

The uncertainty of whether/how to treat asymptomatic patients with isolated severe aortic stenosis and normal left ventricular ejection fraction is one of the most topical in cardiovascular medicine. Recently, the AVATAR trial: first ever randomized trial in the setting of aortic stenosis has been started in an attempt to adequately address this 'burning issue'. In light of this fact it is important to identify biomarkers which might help in risk stratification of these patients, not only in the referring physician's office during a routine exam, but also for preoperative patients scheduled for surgical replacement/transcatheter aortic valve implantation. This report is focusing on novel laboratory parameters which might be helpful in this risk stratification.

Application of Cardiac Troponin in Cardiovascular Diseases Other Than Acute Coronary Syndrome

BACKGROUND

Increased cardiac troponin concentrations in acute coronary syndrome (ACS) identify patients with ongoing cardiomyocyte necrosis who are at increased risk. However, with the use of more precise assays, cardiac troponin increases are commonly noted in other cardiovascular conditions as well. This has generated interest in the use of cardiac troponin for prognostic assessment and clinical management of these patients. In this review, we have summarized the data from studies investigating the implications of cardiac troponin concentrations in various acute and chronic conditions beyond ACS, i.e., heart failure, myocarditis, Takotsubo cardiomyopathy, aortic dissection, supraventricular arrhythmias, valve disease, pulmonary arterial hypertension, stroke, and in the perioperative setting.

CONTENT

Cardiac troponin concentrations are often detectable and frankly increased in non-ACS conditions, in particular when measured with high-sensitivity (hs) assays. With the exception of myocarditis and Takotsubo cardiomyopathy, cardiac troponin concentrations carry strong prognostic information, mainly with respect to mortality, or incipient and/or worsening heart failure. Studies investigating the prognostic benefit associated with cardiac troponin–guided treatments however, are almost lacking and the potential role of cardiac troponin in the management of non-ACS conditions is not defined.

SUMMARY

Increased cardiac troponin indicates increased risk for adverse outcome in patients with various cardiovascular conditions beyond ACS. Routine measurement of cardiac troponin concentrations can however, not be generally recommended unless there is a suspicion of ACS. Nonetheless, any finding of an increased cardiac troponin concentration in a patient without ACS should at least prompt the search for possible underlying conditions and these should be managed meticulously according to current guidelines to improve outcome.

High-Sensitivity Troponin T vs I in Acute Coronary Syndrome: Prediction of Significant Coronary Lesions and Long-term Prognosis

BACKGROUND

High-sensitivity cardiac troponin (hs-cTn) T and I assays are established as crucial tools for the diagnosis of acute myocardial infarction (AMI), as they have been found superior to old troponin assays. However, eventual differences between the assays in prediction of significant coronary lesions and long-term prognosis in patients with acute coronary syndrome (ACS) have not been fully unraveled.

METHODS

Serum concentrations of hs-cTnT (Roche), hs-cTnI (Abbott), and amino-terminal pro-B-type natriuretic peptide (NT-proBNP; Roche) in 390 non-ST-elevation (NSTE) ACS patients were evaluated in relation to significant coronary lesions on coronary angiography (defined as a stenosis >50% of the luminal diameter, with need for revascularization) and prognostic accuracy for cardiovascular mortality, all-cause mortality, as well as the composite end point of cardiovascular mortality and hospitalizations for AMI or heart failure.

RESULTS

The mean (SD) follow-up was 2921 (168) days. Absolute hs-cTnI concentrations were significantly higher than the hs-cTnT concentrations. The relationship between analyzed biomarkers and significant coronary lesions on coronary angiography, as quantified by the area under the ROC curve (AUC), revealed no difference between hs-cTnT [AUC, 0.81; 95% CI, 0.77-0.86] and hs-cTnI (AUC, 0.81; 95% CI, 0.76-0.86; P = NS). NT-proBNP was superior to both hs-cTn assays regarding prognostic accuracy for both cardiovascular and all-cause mortality and for the composite end point during follow-up, also in multivariate analyses.

CONCLUSIONS

The hs-cTnT and hs-cTnI assays displayed a similar ability to predict significant coronary lesions in NSTE-ACS patients. NT-proBNP was superior to both hs-cTn assays as a marker of long-term prognosis in this patient group.

High-Sensitivity Cardiac Troponin Concentrations in Patients with Chest Discomfort: Is It the Heart or the Kidneys As Well?

BACKGROUND

High-sensitivity cardiac troponins (hs-cTn) are the preferred biomarkers to detect myocardial injury, making them promising risk-stratifying tools for patients with symptoms of chest pain. However, circulating hs-cTn are also elevated in other conditions like renal dysfunction, complicating appropriate interpretation of low-level hs-cTn concentrations.

METHODS

A cross-sectional analysis was performed in 1864 patients with symptoms of chest discomfort from the cardiology outpatient department who underwent cardiac computed tomographic angiography (CCTA). Serum samples were analyzed using hs-cTnT and hs-cTnI assays. Renal function was measured by the estimated glomerular filtration rate (eGFR), established from serum creatinine and cystatin C. On follow-up, the incidence of adverse events was assessed.

RESULTS

Median hs-cTnT and hs-cTnI concentrations were 7.2(5.8-9.2) ng/L and 2.6(1.8-4.1) ng/L, respectively. Multivariable regression analysis revealed that both assay results were more strongly associated with eGFR (hs-cTnT:stβ:-0.290;hs-cTnI:stβ:-0.222) than with cardiac imaging parameters, such as coronary calcium score, CCTA plaque severity score and left ventricular mass (all p<0.01). Furthermore, survival analysis indicated lower relative risks in patients with normal compared to reduced renal function for hs-cTnT [HR(95%CI), 1.02(1.00-1.03) compared to 1.07(1.05-1.09)] and hs-cTnI [1.01(1.00-1.01) compared to 1.02(1.01-1.02)] (all p<0.001).

CONCLUSION

In patients with chest discomfort, we identified an independent influence of renal function on hs-cTn concentrations besides CAD, that affected the association of hs-cTn concentrations with adverse events. Estimating renal function is therefore warranted when interpreting baseline hs-cTn concentrations.

Troponin elevations in patients with chronic cardiovascular disease: An analysis of current evidence and significance

Serum troponin elevation above the 99^th percentile of the upper reference limit in healthy subjects (<0.01 ng/ml measured using currently available high-sensitivity cardiac troponin laboratory assays) is required to establish the diagnosis the diagnosis of myocardial necrosis in acute cardiovascular syndromes, as well as guide prognosis and therapy. In the perioperative period, for patients with cardiac disease undergoing noncardiac surgery, it is a particularly critical biomarker universally used to assess the myocardial damage. The value of troponin testing and elevation (as well as its significance) in patients with chronic cardiac valvular, vascular, and renal disease is relatively less well understood. This evidence-based review seeks to examine the currently available data assessing the significance of troponin elevation in certain chronic valvular and other disease states.

Calcific aortic stenosis

Calcific aortic stenosis (AS) is the most prevalent heart valve disorder in developed countries. It is characterized by progressive fibro-calcific remodelling and thickening of the aortic valve leaflets that, over years, evolve to cause severe obstruction to cardiac outflow. In developed countries, AS is the third-most frequent cardiovascular disease after coronary artery disease and systemic arterial hypertension, with a prevalence of 0.4% in the general population and 1.7% in the population >65 years old. Congenital abnormality (bicuspid valve) and older age are powerful risk factors for calcific AS. Metabolic syndrome and an elevated plasma level of lipoprotein(a) have also been associated with increased risk of calcific AS. The pathobiology of calcific AS is complex and involves genetic factors, lipoprotein deposition and oxidation, chronic inflammation, osteoblastic transition of cardiac valve interstitial cells and active leaflet calcification. Although no pharmacotherapy has proved to be effective in reducing the progression of AS, promising therapeutic targets include lipoprotein(a), the renin-angiotensin system, receptor activator of NF-κB ligand (RANKL; also known as TNFSF11) and ectonucleotidases. Currently, aortic valve replacement (AVR) remains the only effective treatment for severe AS. The diagnosis and staging of AS are based on the assessment of stenosis severity and left ventricular systolic function by Doppler echocardiography, and the presence of symptoms. The introduction of transcatheter AVR in the past decade has been a transformative therapeutic innovation for patients at high or prohibitive risk for surgical valve replacement, and this new technology might extend to lower-risk patients in the near future.

The role of cardiac biochemical markers in aortic stenosis

Calcified aortic stenosis is one of the most common causes of heart failure in the elderly. Current guidelines recommend aortic valve replacement in patients with severe disease and evidence of decompensation based on either symptoms or impaired systolic ejection fraction. However, symptoms are often subjective whilst impaired ejection fraction is not a sensitive marker of ventricular decompensation. Interest has surrounded the use of cardiac biochemical markers as objective measures of left ventricular decompensation in aortic stenosis. We will first examine mechanisms of release of biochemical markers associated with myocardial wall stress (BNP/NT-proBNP), myocardial fibrosis (markers of collagen metabolism, galectin-3, soluble ST2) and myocyte death/myocardial ischemia (high-sensitivity cardiac troponins, heart-type fatty acid binding protein, myosin-binding protein C); and discuss future directions of these markers.

Post-Procedural Troponin Elevation and Clinical Outcomes Following Transcatheter Aortic Valve Implantation

Background

Biomarkers of myocardial injury increase frequently during transcatheter aortic valve implantation (TAVI). The impact of postprocedural cardiac troponin (cTn) elevation on short‐term outcomes remains controversial, and the association with long‐term prognosis is unknown.

Methods and Results

We evaluated 577 consecutive patients with severe aortic stenosis treated with TAVI between 2007 and 2012. Myocardial injury, defined according to the Valve Academic Research Consortium (VARC)‐2 as post‐TAVI cardiac troponin T (cTnT) >15× the upper limit of normal, occurred in 338 patients (58.1%). In multivariate analyses, myocardial injury was associated with higher risk of all‐cause mortality at 30 days (adjusted hazard ratio [HR], 8.77; 95% CI, 2.07–37.12; P=0.003) and remained a significant predictor at 2 years (adjusted HR, 1.98; 95% CI, 1.36–2.88; P<0.001). Higher cTnT cutoffs did not add incremental predictive value compared with the VARC‐2–defined cutoff. Whereas myocardial injury occurred more frequently in patients with versus without coronary artery disease (CAD), the relative impact of cTnT elevation on 2‐year mortality did not differ between patients without CAD (adjusted HR, 2.59; 95% CI, 1.27–5.26; P=0.009) and those with CAD (adjusted HR, 1.71; 95% CI, 1.10–2.65; P=0.018; P for interaction=0.24). Mortality rates at 2 years were lowest in patients without CAD and no myocardial injury (11.6%) and highest in patients with complex CAD (SYNTAX score >22) and myocardial injury (41.1%).

Conclusions

VARC‐2–defined cTnT elevation emerged as a strong, independent predictor of 30‐day mortality and remained a modest, but significant, predictor throughout 2 years post‐TAVI. The prognostic value of cTnT elevation was modified by the presence and complexity of underlying CAD with highest mortality risk observed in patients combining SYNTAX score >22 and evidence of myocardial injury.

The influence of heart failure co-morbidity on high-sensitivity troponin T levels in COPD exacerbation in a prospective cohort study: data from the Akershus cardiac examination (ACE) 2 study

CONTEXT

Troponin (hs-TnT) levels predict mortality after acute exacerbation of COPD (AECOPD). Whether this is independent of heart failure (HF) is not established.

MATERIAL AND METHODS

Prospectively included AECOPD patients adjudicated for acute HF categorized into three groups: (A) AECOPD, but acute HF the primary cause for hospitalization; (B) AECOPD the primary cause, but co-existing myocardial dysfunction and (C) AECOPD without myocardial dysfunction.

RESULTS

About 103 AECOPD patients; 18% A, 27% B and 54% C. Hs-TnT level differed between the groups: (ng/l, median) A: 41, B: 25 and C: 15, p = 0.03 for A versus B and p = 0.005 for B versus C. During a median 826 days, 47% died. In Cox analysis, hs-TnT levels remained associated with mortality (hazard ratio per 10 ng/l 1.3, p < 0.0001).

CONCLUSION

hs-TnT levels are influenced by myocardial dysfunction/HF in AECOPD, but provide independent prognostic information. The prognostic merit of hs-TnT cannot be attributed to HF alone.

Timing of Dynamic NT-proBNP and hs-cTnT Response to Exercise Challenge in Asymptomatic Children with Moderate Aortic Valve Regurgitation or Moderate Aortic Valve Stenosis

Patients with congenital aortic valve stenosis (AVS) can remain asymptomatic but may develop progressive and often underestimated exercise intolerance. The risk of increased left ventricular (LV) wall stress, irreversible myocardial fibrosis and sudden death in untreated patients warrants earlier intervention. The timing for curative therapy for severe AVS is clear, but optimal timing for moderate stenosis (modAS) is unknown. AVS often coexists with aortic regurgitation, which adds a volume overload to an already pressure-overloaded LV, adding an additional challenge to the estimation of disease severity. We investigated the possible value of N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) upon treadmill exercise challenge in children with asymptomatic modAS versus moderate regurgitation (modAR). The aim was to determine optimal timing of peak biochemical response. Blood samples were obtained at rest, and then at 20, 40 and 60 min after peak exercise comparing modAS and modAR to healthy controls. Exercise performance was equivalent in all groups, with no difference for biomarker levels at rest. The increase in NT-proBNP was significant in modAR at 40 min (99.2 ± 48.6 ng/L; p = 0.04) and 60 min into recovery (100.0 ± 53.7 ng/L; p = 0.01), but not in modAS. The increase in hs-cTnT was significant only at 60 min into recovery for modAS and modAR. NT-proBNP and hs-cTnT following exercise challenge are possible discriminant biomarkers of modAR from modAS and controls at 60 min into recovery despite comparable exercise performance. This offers a promising avenue for future stratification of aortic valve disease and optimal timing of intervention.

Biomarkers in Cardiology - Part 2: In Coronary Heart Disease, Valve Disease and Special Situations

Cardiovascular diseases are the main causes of mortality and morbidity in Brazil. Their primary and secondary preventions are a priority for the health system and require multiple approaches for increased effectiveness. Biomarkers are tools used to identify with greater accuracy high-risk individuals, establish a faster diagnosis, guide treatment, and determine prognosis. This review aims to highlight the importance of biomarkers in clinical cardiology practice and raise relevant points regarding their application and perspectives for the next few years. This document was divided into two parts. This second part addresses the application of biomarkers in coronary heart disease, valvular diseases, cardio-oncology, pulmonary embolism, and cardiorenal syndrome.

Impact of Sex on the Prognostic Value of High-Sensitivity Cardiac Troponin I in the General Population: The HUNT Study

BACKGROUND

A new, high-sensitivity assay for cardiac troponin I (hs-cTnI) permits evaluation of the prognostic value of cardiac troponins within the reference interval. Men have higher hs-cTnI concentrations than women, but the underlying pathophysiological mechanisms and prognostic implications are unclear. The aim of this study was to assess the potential impact of sex on the association between hs-cTnI and cardiovascular death.

METHODS

By use of the Architect STAT High-Sensitive Troponin assay, we measured hs-cTnI in 4431 men and 5281 women aged ≥20 years participating in the prospective observational Nord-Trøndelag Health Study (HUNT).

RESULTS

hs-cTnI was detectable in 98.5% of men and 94.7% of women. During a mean follow-up period of 13.9 years, 708 cardiovascular deaths were registered. hs-cTnI was associated with the incidence of cardiovascular death [adjusted hazard ratio (HR) per 1 SD in log hs-cTnI 1.23 (95% CI 1.15–1.31)], with higher relative risk in women than men [HR 1.44 (1.31–1.58) vs 1.10 (1.00–1.20); Pinteraction &lt; 0.001]. This finding was mediated by both lower risk associated with low hs-cTnI concentrations in women than in men and higher risk associated with high concentrations of hs-cTnI in women than in men. Male sex was associated with a higher risk of cardiovascular death [HR 1.28 (1.11–1.49)], but after adjustment for hs-cTnI, this association disappeared [HR 0.87 (0.75–1.02)].

CONCLUSIONS

The prognostic value of hs-cTnI concentrations in the general population is stronger in women than in men. Subtle impairment of cardiovascular status may contribute to higher hs-cTnI concentrations in men, reflecting sex-dependent differences in cardiovascular risk.

Impact of left ventricular hypertrophy on troponin release during acute myocardial infarction: new insights from a comprehensive translational study

BACKGROUND

Biomarkers are frequently used to estimate infarct size (IS) as an endpoint in experimental and clinical studies. Here, we prospectively studied the impact of left ventricular (LV) hypertrophy (LVH) on biomarker release in clinical and experimental myocardial infarction (MI).

METHODS AND RESULTS

ST-segment elevation myocardial infarction (STEMI) patients (n=140) were monitored for total creatine kinase (CK) and cardiac troponin I (cTnI) over 72 hours postinfarction and were examined by cardiac magnetic resonance (CMR) at 1 week and 6 months postinfarction. MI was generated in pigs with induced LVH (n=10) and in sham-operated pigs (n=8), and serial total CK and cTnI measurements were performed and CMR scans conducted at 7 days postinfarction. Regression analysis was used to study the influence of LVH on total CK and cTnI release and IS estimated by CMR (gold standard). Receiver operating characteristic (ROC) curve analysis was performed to study the discriminatory capacity of the area under the curve (AUC) of cTnI and total CK in predicting LV dysfunction. Cardiomyocyte cTnI expression was quantified in myocardial sections from LVH and sham-operated pigs. In both the clinical and experimental studies, LVH was associated with significantly higher peak and AUC of cTnI, but not with differences in total CK. ROC curves showed that the discriminatory capacity of AUC of cTnI to predict LV dysfunction was significantly worse for patients with LVH. LVH did not affect the capacity of total CK to estimate IS or LV dysfunction. Immunofluorescence analysis revealed significantly higher cTnI content in hypertrophic cardiomyocytes.

CONCLUSIONS

Peak and AUC of cTnI both significantly overestimate IS in the presence of LVH, owing to the higher troponin content per cardiomyocyte. In the setting of LVH, cTnI release during STEMI poorly predicts postinfarction LV dysfunction. LV mass should be taken into consideration when IS or LV function are estimated by troponin release.