Determinants of minimal elevation in high-sensitivity cardiac troponin T in the general population

Cardiac troponin T associates with left ventricular function and synchrony assessed by CMR in the general population: results from the Akershus Cardiac Examination 1950 Study

Background and aim

Cardiac troponin T (cTnT) is a blood biomarker of myocardial injury that is associated with future adverse cardiovascular events in the general population. Left ventricular (LV) global longitudinal strain (GLS) and mechanical dispersion (MD) are metrics of systolic function and synchrony that can be obtained from cardiac imaging. Studies suggest an association between cTnT and echocardiographically assessed GLS and MD, but it is unknown whether cTnT relates to these metrics when assessed by cardiac magnetic resonance (CMR). We hypothesized that cTnT associates with GLS and with MD assessed by CMR feature tracking (CMR-FT) in the general population.

Methods and results

cTnT and CMR-FT measurements were performed in 186 community dwellers from the Akershus Cardiac Examination 1950 Study. The participants' age ranged from 68 to 70 years. Median cTnT concentration was 7.0 ng/L (interquartile interval 5.0-12.6 ng/L), median absolute value of GLS was 17.3% (interquartile interval 15.7-18.8%), and median MD was 80.7 milliseconds (interquartile interval 61.8-105.0 milliseconds). In multivariable linear regression models adjusted for common clinical risk factors of cardiovascular disease, with GLS and MD as outcome and cTnT as the predictor variable of interest, log10 transformed cTnT was significantly associated with both absolute GLS [β-coefficient -1.65, confidence interval (-2.84, -0.46)] and MD [β-coefficient 28.56, confidence interval (12.14, 44.92)].

Conclusion

In older adults from the general population, higher cTnT concentrations are associated with worse systolic function and synchrony assessed by CMR-FT LV GLS and MD, adding information about myocardial function to traditional risk factors.

Clinical Interpretation of Serum Troponin in the Era of High-Sensitivity Testing

Cardiac troponin (Tn) plays a central role in the evaluation of patients with angina presenting with acute coronary syndrome. The advent of high-sensitivity assays has improved the analytic sensitivity and precision of serum Tn measurement, but this advancement has come at the cost of poorer specificity. The role of clinical judgment is of heightened importance because, more so than ever, the interpretation of serum Tn elevation hinges on the careful integration of findings from electrocardiographic, echocardiographic, physical exam, interview, and other imaging and laboratory data to formulate a weighted differential diagnosis. A thorough understanding of the epidemiology, mechanisms, and prognostic implications of Tn elevations in each cardiac and non-cardiac etiology allows the clinician to better distinguish between presentations of myocardial ischemia and myocardial injury-an important discernment to make, as the treatment of acute coronary syndrome is vastly different from the workup and management of myocardial injury and should be directed at the underlying cause.

Characterization of Myocardial Injury With High-Sensitivity Troponin

BACKGROUND

High-sensitivity troponin I, cardiac form (hs-cTnI) accelerates the assessment of acute coronary syndrome. Little has been documented about its performance, how it relates to different types of myocardial injury, and its impact on morbidity and mortality. This study sought to expand understanding of hs-cTnI by characterizing types of myocardial injury, the impact of comorbidities, and 30-day outcomes.

METHODS

The study retrospectively evaluated 1,975 patients with hs-cTnI levels obtained in the emergency department or inpatient setting from June to September 2020. Troponin was considered elevated if it was higher than the 99th percentile for either sex. Charts were reviewed to determine the presence of myocardial injury. Troponin elevation was adjusted for demographics, comorbidities, and kidney dysfunction. Thirty-day mortality and readmission rates were calculated.

RESULTS

Of 1,975 patients, 468 (24%) had elevated hs-cTnI, and 330 (17%) had at least 1 type of myocardial injury, type 2 myocardial infarction being the most frequent. Sensitivity and specificity using the 99th percentile as a cutoff were 99% and 92%, respectively. The average maximum hs-cTnI level was significantly higher for type 1 myocardial infarction (P < .001). Being male, Black, non-Hispanic, and a hospital inpatient were all associated with higher initial and peak hs-cTnI levels (P < .001). Elevated hs-cTnI level, age, heart disease, kidney dysfunction, and inpatient status were predictive of 30-day mortality on multivariate analysis.

CONCLUSION

Elevated hs-cTnI levels in emergency department and inpatient settings occurs most commonly because of type 2 myocardial infarction. Maximum hs-cTnI level is associated with the patient's particular type of myocardial injury, certain demographics, and cardiovascular comorbidities, and it may be a predictor of 30-day outcomes.

Single Troponin Measurement to Rule Out Myocardial Infarction: JACC Review Topic of the Week

The term "single-sample rule-out" refers to the ability of very low concentrations of high-sensitivity cardiac troponin (hs-cTn) on presentation to exclude acute myocardial infarction with high clinical sensitivity and negative predictive value. Observational and randomized studies have confirmed this ability. Some guidelines endorse use of a concentration of hs-cTn at the assay's limit of detection, while other studies have validated the use of higher concentrations, allowing this approach to identify a greater proportion of patients at low risk. In most studies, at least 30% of patients can be triaged with this approach. The concentration of hs-cTn varies according to the assay used and sometimes how regulations permit reporting. It is clear that patients need to be at least 2 hours from the onset of symptoms being evaluated. Caution is warranted, particularly with older patients, women, and patients with underlying cardiac comorbidities.

Association between high-sensitivity cardiac troponin T levels and incident stroke in the elderly Japanese population: Results from the Tohoku Medical Megabank Community-based Cohort Study

Elevated levels of circulating high-sensitivity cardiac troponin T (hs-cTnT) are associated with cardiovascular disease. This study aimed to examine whether hs-cTnT levels are associated with incident stroke in the elderly population. The Iwate Tohoku Medical Megabank Organization pooled participant data for a community-based cohort study (n = 15,063, 69.6 ± 3.4 years), with a mean follow-up period of 5.23 years for all-cause death and incident stroke. The follow-up revealed 316 incident strokes, including atherothrombotic (n = 98), cardioembolic (n = 54), lacunar (n = 63), hemorrhagic (n = 101), and 178 all-cause deaths. Participants were classified into quartiles according to hs-cTnT levels (Q1 ≦ 4 ng/L, Q2: 5-6 ng/L, Q3: 7-9 ng/L, and Q4 > 9 ng/L). After adjusting for sex, age, smoking, drinking, systolic blood pressure, estimated glomerular filtration rate, N-terminal pro-brain natriuretic peptide, hemoglobin A1c, and lipid profile, a Cox proportional hazard model showed that higher hs-cTnT levels were associated with ischemic stroke (Q1 vs. Q4, hazard ratio [HR] = 2.24, 95 % confidence interval [CI] = 1.12-4.51, p = 0.023). The incident of total stroke was not associated with hs-cTnT levels (Q1 vs. Q4, HR 1.39, 95 % CI = 0.89-1.74, p = 0.145). Numerical differences were highest regarding incident lacunar stroke subtypes; however, this association was not statistically significant. Higher hs-cTnT concentrations were associated with ischemic stroke in the elderly Japanese population.

Biomarker Development in Cardiology: Reviewing the Past to Inform the Future

Cardiac biomarkers have become pivotal to the clinical practice of cardiology, but there remains much to discover that could benefit cardiology patients. We review the discovery of key protein biomarkers in the fields of acute coronary syndrome, heart failure, and atherosclerosis, giving an overview of the populations they were studied in and the statistics that were used to validate them. We review statistical approaches that are currently in use to assess new biomarkers and overview a framework for biomarker discovery and evaluation that could be incorporated into clinical trials to evaluate cardiovascular outcomes in the future.

High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population

Cardiac troponins (cTns) I and T have long been the most successful cardiac-specific circulating biomarkers in cardiovascular (CV) medicine, having changed dramatically the diagnosis of acute myocardial infarction, while being independent predictors of outcome in several cardiac conditions and non-cardiac conditions. The latest-generation high-sensitivity (hs) cTn assays demonstrate both enhanced diagnostic performance and improved analytical performance, with the ability to measure detectable concentrations in a substantial proportion of the asymptomatic and presumably healthy populations. Given this unique analytical feature, recent evidence suggests that hs-cTn can be used for the stratification of CV risk in the general population. High-sensitivity cTn predicts future CV events, are responsive to preventive pharmacological or lifestyle interventions, change in parallel to risk modifications, and offer incremental risk prediction when added to well-established prognosticators. The implementation of CV risk stratification and prevention strategies incorporating hs-cTn requires further investigation to define the optimal target populations, timing of measurement, and preventive interventions.

High-sensitivity cardiac troponin T and the risk of heart failure in postmenopausal women of the ARIC Study

OBJECTIVE

We investigated isolated and joint effects of early menopause (occurrence before 45 y of age) and high-sensitivity cardiac troponin T elevation (hs-cTnT ≥ 14 ng/L) on heart failure (HF) incidence in postmenopausal women.

METHODS

We included 2,276 postmenopausal women, aged 67-90 years, with hs-cTnT measurements and without prevalent HF from the Atherosclerosis Risk in Communities study Visit 5 (2011-2013). Women were categorized according to early menopause and hs-cTnT group. Cox proportional hazards models were used for analysis.

RESULTS

Over a median follow-up of 5.5 years, we observed 104 HF events. The incidence rates of HF were greater in women with hs-cTnT elevation when compared to those without hs-cTnT elevation. In unadjusted analysis, the hazard ratios for incident HF were threefold greater in women with hs-cTnT elevation, with or without early menopause, (3.03 [95% CI, 1.59-5.77]) and (3.29 [95% CI, 2.08-5.21]), respectively, but not significantly greater in women with early menopause without hs-cTnT elevation, when compared to women with neither early menopause nor hs-cTnT elevation at Visit 5. After adjusting for HF risk factors and NT-pro B-type natriuretic peptide, these associations were attenuated and became nonsignificant for women with hs-cTnT elevation, but became stronger and significant for women with early menopause without hs-cTnT elevation (2.39 [95% CI, 1.28-4.46]).

CONCLUSIONS

Irrespective of early menopause status, hs-cTnT elevation is associated with greater HF incidence but this association is partially explained by HF risk factors. Even in the absence of hs-cTnT elevation, early menopause is significantly associated with HF incidence after accounting for HF risk factors.

Evidence for a Direct Harmful Effect of Alcohol on Myocardial Health: A Large Cross-Sectional Study of Consumption Patterns and Cardiovascular Disease Risk Biomarkers From Northwest Russia, 2015 to 2017

Background Alcohol drinking is an increasingly recognized risk factor for cardiovascular disease. However, there are few studies of the impact of harmful and hazardous drinking on biomarkers of myocardial health. We conducted a study in Russia to investigate the impact of heavy drinking on biomarkers of cardiac damage and inflammation. Methods and Results The Know Your Heart study recruited a random sample of 2479 participants from the population of northwest Russia (general population) plus 278 patients (narcology clinic subsample) with alcohol problems. The general population sample was categorized into harmful drinkers, hazardous drinkers, nonproblem drinkers, and nondrinkers, according to self-reported level of alcohol consumption, whereas the narcology clinic sample was treated as the separate group in the analysis. Measurements were made of the following: (1) high-sensitivity cardiac troponin T, (2) NT-proBNP (N-terminal pro-B-type natriuretic peptide), and (3) hsCRP (high-sensitivity C-reactive protein). The narcology clinic subsample had the most extreme drinking pattern and the highest levels of all 3 biomarkers relative to nonproblem drinkers in the general population: high-sensitivity cardiac troponin T was elevated by 10.3% (95% CI, 3.7%-17.4%), NT-proBNP by 46.7% (95% CI, 26.8%-69.8%), and hsCRP by 69.2% (95% CI, 43%-100%). In the general population sample, NT-proBNP was 31.5% (95% CI, 3.4%-67.2%) higher among harmful drinkers compared with nonproblem drinkers. Overall, NT-proBNP and hsCRP increased with increasing intensity of alcohol exposure (test of trend P<0.001). Conclusions These results support the hypothesis that heavy alcohol drinking has an adverse effect on cardiac structure and function that may not be driven by atherosclerosis.

Can High-Sensitivity Troponins Predict Future Hypertension? A Systematic Literature Review

Hypertension (HT) is associated with cardiovascular events and increased mortality, and identification of persons at risk in due time is therefore important. Finding a biomarker to identify those at risk will enable early preventive treatment, and high-sensitivity cardiac troponin (hs-cTn) seems to be a highly relevant candidate. To gather the existing knowledge on the association between hs-cTn and future HT, a systematic literature review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) reporting guidelines and using the PICOS system. Medline was searched until August 2018. Of 45 extracted papers, eleven papers were eligible for the study. None were randomized controlled trials. Three studies assessed hs-cTnI, eight studies assessed hs-cTnT. All studies found statistically significant associations between hs-cTn concentrations and future HT, but the studies included different types of blood pressure (diastolic, systolic, diurnal). Due to differences in troponin assay construction and test capability, a direct comparison of test performance in terms of specificity, sensitivity and predictive values was not possible, and a specific hs-cTn cutoff value for HT prediction could therefore not be defined. Furthermore, a number of conditions known to affect troponin concentrations (e.g. gender, renal function, and co-morbidities) were not sufficiently studied. All retrieved studies found significant associations between hs-cTn concentrations and future HT; although the findings are promising, the studies were too heterogeneous, and many conditions affecting troponin concentrations needs investigation at these low concentrations before hs-cTn can be considered a useful HT predictor.

Premorbid levels of high-sensitivity cardiac troponin T and natriuretic peptide and prognosis after incident myocardial infarction

High-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) at the time of myocardial infarction (MI) are strong predictors of prognosis. However, whether their premorbid (before MI occurrence) levels are associated with prognosis after incident MI is unknown.

METHODS

In 1,054 participants from the Atherosclerosis Risk in Communities Study with incident MI, we evaluated premorbid levels of hs-cTnT and NT-proBNP measured on median 5.8 (interquartile interval 3.0-11.5 [mean 5.5]) years prior to incident MI and their associations with subsequent composite and individual outcomes of all-cause mortality, cardiovascular mortality, recurrent MI, heart failure, and stroke.

RESULTS

During a median follow-up of 3.0 years after MI, 801 participants developed the composite outcome. Both hs-cTnT and NT-proBNP were independently associated with the composite outcome after incident MI. Among individual outcomes, all-cause mortality, cardiovascular mortality, and heart failure showed significant associations with both cardiac markers. Overall, NT-proBNP demonstrated a more evident relationship than hs-cTnT. Indeed, the addition of premorbid NT-proBNP alone, but not hs-cTnT alone, to conventional predictors at incident MI significantly improved risk prediction of the composite outcome after incident MI (Δc-statistic 0.013 [95% CI 0.005-0.022] from 0.691 with conventional predictors).

CONCLUSIONS

Premorbid levels of hs-cTnT and NT-proBNP assessed on average 6 years prior to incident MI were associated with adverse outcomes after incident MI. These results further highlight the importance of cardiac health at an earlier stage of life.

Variability in High-Sensitivity Cardiac Troponin T Testing in Stable Patients With and Without Coronary Artery Disease

BACKGROUND

High-sensitivity cardiac troponin T (hs-cTnT) is used to diagnosis acute myocardial infarction, often based on values exceeding the 99th percentile threshold (14 ng/L) of normal populations. The short- and long-term variability of hs-cTnT in stable patients with or without coronary artery disease (CAD) is unknown.

METHODS

Prospective cohort study of 75 stable patients with CAD and 3 differing clinical profiles (stable angina [SA]; remote myocardial infarction [MI]; repetitive acute coronary syndrome [ACS]) and 25 controls without angiographic CAD, each with 15 hs-cTnT measurements over 1 year.

RESULTS

Individual results (1491 measurements) did not vary over within-day, daily, weekly, monthly, seasonal, or yearly time windows. The overall median was 2.8 ng/L (interquartile range [IQR] 5.2 ng/L) with the highest median (6.3 ng/L) and variability (IQR 6. 9 ng/L) in the repetitive ACS group. Diabetes, impaired renal function, and raised C-reactive protein were independent predictors of higher hs-cTnT values (average increase by 8.5 ng/L [95% CI, 5.0-11.9], 5.0 ng/L [95% CI, 2.0-8.1] and 4.0 ng/L (95% CI, 1.0-7.0), respectively). The 99th percentile value of all hs-cTnT measurements in the combined stable patients with CAD was 39 ng/L compared with 14 ng/L in the non-CAD patients.

CONCLUSIONS

Individual hs-cTnT readings in both patients with and without CAD were stable over hours, days, weeks, and months. Diabetes, poor renal function, and elevated C-reactive protein were independent predictors of higher median and IQR hs-cTnT values, often exceeding conventional thresholds. These findings highlight the need for caution and clinical contextualization in the interpretation of hs-cTnT results.

Association between high-sensitivity cardiac troponin T and future cardiovascular incidence in a general Japanese population: results from the Tohoku medical megabank project

Purpose: Elevation of high-sensitivity cardiac troponin T (hs-cTnT) is associated with an increased risk of cardiovascular disease (CVD). This study determined whether hs-cTnT was detectable with N-terminal pro-b-type natriuretic peptide (NT-proBNP) and related to CV risk factors in a general Japanese population. Materials and methods: The Tohoku Medical Megabank Organization pooled individual participant data for a population-based cohort study in the Iwate prefecture (n = 30,193, age = 60.2 ± 11.5 year). Results: Hs-cTnT levels were higher in participants with hypertension, diabetes mellitus than in participants without these conditions (all ps < 0.001). Logistic regression analysis demonstrated that NT-proBNP was strongly associated with elevation of hs-cTnT (OR = 3.35, 95% CI = 2.90-3.89, p < 0.001). The receiver operating characteristic curve analysis showed that hs-cTnT was one of useful biomarker for the differentiation of high risk for CVD (the Suita score ≥ 56) from a general population. Logistic regression analysis demonstrated hs-cTnT levels were related to the CVD high risk group (OR = 2.67, 95% CI = 2.28-3.14, p < 0.001). Conclusions: Hs-cTnT levels are associated with elevation of NT-proBNP and high Suita score, which suggests that elevated hs-cTnT is related to subclinical myocardial damage and indicates CV risk.

New technological devices for the assessment of systemic inflammation in the primary prevention of cardiovascular disease

PURPOSE OF REVIEW

The prediction of cardiovascular disease (CVD) events is of strategic importance for the primary prevention of one of the big killers in the world. Predictive models have a history of decades, but still the desired accuracy is not reached by any of the existing models. The inclusion of inflammatory factors in the models did not increase their accuracy. In this review, we discuss the possible reasons for that failure and we propose a paradigm shift.

RECENT FINDINGS

Systemic inflammation is a very volatile phenomenon. The blood concentration of inflammatory biomarkers may change considerably in one individual with a timescale of seconds. Sudden changes in environmental conditions can trigger rapid modifications in the inflammatory profile of an individual. In routine clinical practice, the blood tests for inflammation are carried out at one point in time, not in standard environmental conditions, and are therefore inadequate.

SUMMARY

We have to direct CVD research toward the understanding of the synchronic relationship between external environmental conditions and internal physiological reactions. CVD risk assessment must be carried out by using continuous real-time monitoring of external and internal parameters together, something that may become possible with the advent of new technological devices.

Assessing Cardiovascular Risk and Testing in Type 2 Diabetes

PURPOSE OF REVIEW

Type 2 diabetes confers approximately twofold-increased risk for cardiovascular disease. Early risk stratification of these patients may help reduce cardiovascular events. This review discusses the state of the art of risk factors, biomarkers, and subclinical disease parameters potentially useful in cardiovascular risk assessment in type 2 diabetes.

RECENT FINDINGS

Scientific progress in the past decade has identified a spectrum of risk in diabetic individuals rather than categorizing diabetes as a coronary heart disease equivalent as previously done. Recent data on emerging biomarkers and diagnostic imaging, along with traditional risk factors, provide evidence to help inform individualized cardiovascular risk assessment. Comprehensive assessment of traditional risk factors, biomarkers, complications of diabetes, and subclinical atherosclerosis may help classify diabetic individuals as low, intermediate, or high risk for determining the intensity of lifestyle modification and pharmacotherapy. Further research may lead to a comprehensive pathway for cardiovascular disease risk assessment in diabetic patients.

Novel Biomarkers for Predicting Cardiovascular Disease in Patients With Diabetes

It is generally acknowledged that patients with diabetes comprise a high-risk population for the development of cardiovascular disease. However, it is perhaps less well recognized that there actually exists considerable heterogeneity in vascular risk within this patient population, with a sizable subset of individuals seemingly at low risk for major cardiovascular events despite the presence of diabetes. Because traditional clinical risk calculators have shown wide variability in their performance in the setting of diabetes, there exists a need for additional risk predictors in this patient population. In this context, there has been considerable interest in the potential utility of circulating biomarkers as clinical tools that might facilitate risk stratification and thereby guide therapeutic and preventative decision-making. Coupled with the current era of dedicated cardiovascular outcome trials in type 2 diabetes, this interest has spawned a growing literature of recent studies that evaluated potential biomarkers. To date, these studies have identified N-terminal pro-B-type natriuretic peptide, high-sensitivity cardiac troponins, and growth differentiation factor-15 as cardiovascular biomarkers of particular potential in patients with diabetes. Furthermore, recognizing the potential benefit of collective consideration of different biomarkers reflecting distinct pathophysiologic processes that might contribute to the development of cardiovascular disease, there is emerging emphasis on the evaluation of combinations of biomarkers for optimal risk prediction. Although not currently ready for clinical practice, this rapidly-growing topic of biomarker research might ultimately facilitate the goal of individualized risk stratification and thereby enable truly personalized management of diabetes.

N-terminal pro-brain natriuretic peptide and associated factors in the general working population: a baseline survey of the Uranosaki cohort study

Few data on clinical characteristics associated with N-terminal pro-brain natriuretic peptide (NT-proBNP) or the clinical value of measuring NT-proBNP in the working population are available. The aim of the present study was to investigate the levels of NT-proBNP and their association with clinical variables in the Japanese general working population by using baseline data from the Uranosaki cohort study. In the study, the plasma concentration of NT-proBNP and some biomarkers were measured in addition to the standard health checkups at the workplace. Questionnaires regarding health-related quality of life (HR-QOL) were also completed. A total of 2140 participants were enrolled in the study. Plasma levels of NT-proBNP were positively associated with age, female sex, systolic blood pressure, pulse pressure, prevalent hypertension, smoking habit, high-density lipoprotein cholesterol (HDL-C), and prevalent proteinuria, and negatively associated with body mass index, lipid profiles except HDL-C, uric acid, renal function, and hemoglobin. Both the plasma concentration of high-molecular weight adiponectin and that of high-sensitivity troponin T were positively and independently associated with NT-proBNP. In addition, the HR-QOL score regarding sleep disorder was independently associated with NT-proBNP. Thus, we have obtained evidence that the plasma NT-proBNP is affected by several clinical variables in the general working population.

Oral health and systemic inflammatory, cardiac and nitroxid biomarkers in hemodialysis patients

Background

Periodontal diseases have systemic inflammatory effects and have been adversely associated with cardiovascular diseases, which are also the most frequent cause of death in the end-stage renal disease. The aim of this cross-sectional study was to investigate the oral health and serum biomarkers among the hemodialysis (HD) patients in Slovenia.

Material and Methods

111 HD patients were periodontally examined and their sera were assayed for C reactive protein (CRP), cardiac troponin T (TnT), nitrite/nitrate (NOx) and antibody levels to A. actinomycetemcomitans and P. gingivalis. The association of oral health with systemic response was analyzed with Kruskal-Wallis test, Fisher’s exact test and multivariate linear regression.

Results

Bleeding on probing without periodontal pockets was present in 5.2%, calculus without periodontal pockets in 42.1%, shallow periodontal pockets in 39.5% and deep periodontal pockets in 13.2% of dentate patients. There were 28.8% edentulous participants. 63.1% of the patients had CRP levels higher than 3 mg/L and 34.2% higher than 10 mg/L. TnT was detectable in all participants, with 25.2% exhibiting levels higher than 100 ng/L. The median level of NOx was 43.1 µmol/L. Participants with higher CRP were more likely to be edentulous and have higher TnT levels. A direct association of oral health with TnT or NOx was not detected.

Conclusions

HD patients in Slovenia have compromised oral health and increased serum inflammatory and cardiac biomarkers. Edentulousness was an independent predictor for the increased CRP, indicating a need for improved dental care to retain the teeth as long as possible.

Key words:Periodontal diseases, edentulousness, C reactive protein, cardiac troponin T, nitric oxide.

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.

Cardiac Cell Senescence and Redox Signaling

Aging is characterized by a progressive loss of the ability of the organism to cope with stressors and to repair tissue damage. As a result, chronic diseases, including cardiovascular disease, increase their prevalence with aging, underlining the existence of common mechanisms that lead to frailty and age-related diseases. In this frame, the progressive decline of the homeostatic and reparative function of primitive cells has been hypothesized to play a major role in the evolution of cardiac pathology to heart failure. Although initially it was believed that reactive oxygen species (ROS) were produced in an unregulated manner as a byproduct of cellular metabolism, causing macromolecular damage and aging, accumulating evidence indicate the major role played by redox signaling in physiology. Aim of this review is to critically revise evidence linking ROS to cell senescence and aging and to provide evidence of the primary role played by redox signaling, with a particular emphasis on the multifunctional protein APE1/Ref in stem cell biology. Finally, we will discuss evidence supporting the role of redox signaling in cardiovascular cells.

Troponin T release is associated with silent myocardial ischaemia in black men: The SABPA Study

Background High sensitivity cardiac troponin T (hs-cTnT) is a validated marker of myocardial damage and may reflect the degree of silent myocardial ischaemia (SMI) and ventricular strain. Our aim was to compare hs-cTnT levels in black and white South Africans taking SMI into consideration. We further explored the capability of hs-cTnT to predict the presence of compensatory systolic hypertension in this South African cohort. Methods A bi-ethnic sex cohort ( n = 404) with similar socioeconomic status (198 black participants and 206 white participants, aged 20-65 years) participated in this target population study where 24 h ambulatory blood pressure, electrocardiogram and overnight fasting cardiometabolic variables were measured. Results Hypertension, higher glycated haemoglobin levels and more frequent and longer SMI events were observed more often in the black participants. Multivariate linear regression analysis showed positive associations between SMI events [Adj. R²= 0.19; β 0.35 (0.08-0.62); p < 0.01], SMI event maximum duration [Adj. R²= 0.17, β 0.43 (0.16-0.70), p < 0.01], SMI total duration [Adj. R²= 0.12; β 0.37 (0.10; 0.65), p = 0.05] and hs-cTnT in black males only.] A lower hs-cTnT cut-point ≥4.2 pg/ml for 24 h systolic hypertension was predicted in the black participants compared with ≥5.6 pg/ml in the white participants (area under the curve 0.66-67 (95% CI: 0.57-0.75), p < 0.001) with a respective sensitivity/specificity of 64/68% and 61/71%. Conclusions hs-cTnT may be a potential marker of SMI in the prediction of systolic blood pressure increases, as well as clusters of risk factors for cardiovascular disease. Ethnic- and possibly sex-specific references values for hs-cTnT should be considered for risk stratification.

Measuring high-sensitivity cardiac troponin T blood concentration in population surveys

INTRODUCTION

The blood test for high-sensitivity cardiac troponin T (HS-CTnT) has been proposed as a marker of cardiovascular risk in the general population, as it is associated with subsequent incidence of cardiovascular events and mortality. We aimed at evaluating the feasibility of HS-CTnT testing within large nationally-representative population surveys in which blood samples are collected during household visits, shipped using the standard civil postal service, and then frozen for subsequent analyses.

METHODS

The Health Survey for England (HSE) consists of a series of annual surveys beginning in 1991. It is designed to provide regular information on various aspects of the nation's health and risk factors. We measured HS-CTnT in the blood of 200 people from the HSE 2016 wave, then froze and stored their blood samples at -40°C for 5-10 weeks, and then thawed and retested them to appreciate the extent of within-person agreement or test-retest reliability of the two measurements.

RESULTS

The Cronbach's Alpha (Scale Reliability Coefficient) and the Interclass Correlation Coefficient (two-way mixed-effects model for consistency of agreement at individual level) were 0.97 (95%CI = 0.96-0.99) and 0.95 (95%CI = 0.94-0.96) respectively. The time delay from blood withdrawal to analysis and storage (1-4 days) did not affect the results, nor did the freezing time before the retest (5-10 weeks).

CONCLUSION

The measurement of HS-CTnT plasma concentration within large nationally-representative surveys such as the Health Survey for England is feasible.