High-Sensitivity Cardiac Troponin I Is a Strong Predictor of Cardiovascular Events and Mortality in the AGES-Reykjavik Community-Based Cohort of Older Individuals

Cost-effectiveness of applying high-sensitivity troponin I to a score for cardiovascular risk prediction in asymptomatic population

INTRODUCTION

Risk stratification scores such as the European Systematic COronary Risk Evaluation (SCORE) are used to guide individuals on cardiovascular disease (CVD) prevention. Adding high-sensitivity troponin I (hsTnI) to such risk scores has the potential to improve accuracy of CVD prediction. We investigated how applying hsTnI in addition to SCORE may impact management, outcome, and cost-effectiveness.

METHODS

Characteristics of 72,190 apparently healthy individuals from the Biomarker for Cardiovascular Risk Assessment in Europe (BiomarCaRE) project were included into a discrete-event simulation comparing two strategies for assessing CVD risk. The standard strategy reflecting current practice employed SCORE (SCORE); the alternative strategy involved adding hsTnI information for further stratifying SCORE risk categories (S-SCORE). Individuals were followed over ten years from baseline examination to CVD event, death or end of follow-up. The model tracked the occurrence of events and calculated direct costs of screening, prevention, and treatment from a European health system perspective. Cost-effectiveness was expressed as incremental cost-effectiveness ratio (ICER) in € per quality-adjusted life year (QALYs) gained during 10 years of follow-up. Outputs were validated against observed rates, and results were tested in deterministic and probabilistic sensitivity analyses.

RESULTS

S-SCORE yielded a change in management for 10.0% of individuals, and a reduction in CVD events (4.85% vs. 5.38%, p<0.001) and mortality (6.80% vs. 7.04%, p<0.001). S-SCORE led to 23 (95%CI: 20-26) additional event-free years and 7 (95%CI: 5-9) additional QALYs per 1,000 subjects screened, and resulted in a relative risk reduction for CVD of 9.9% (95%CI: 7.3-13.5%) with a number needed to screen to prevent one event of 183 (95%CI: 172 to 203). S-SCORE increased costs per subject by 187€ (95%CI: 177 € to 196 €), leading to an ICER of 27,440€/QALY gained. Sensitivity analysis was performed with eligibility for treatment being the most sensitive.

CONCLUSION

Adding a person's hsTnI value to SCORE can impact clinical decision making and eventually improves QALYs and is cost-effective compared to CVD prevention strategies using SCORE alone. Stratifying SCORE risk classes for hsTnI would likely offer cost-effective alternatives, particularly when targeting higher risk groups.

Global research trends on cardiac troponin and physical activity among pediatric populations: a bibliometric analysis and science mapping study

Background

Cardiac troponin (cTn) is a reliable marker for evaluating myocardial damage. cTn is a very specific protein involved in myocardial injury, and it is a key factor in the diagnosis of coronary syndromes. Bibliometric analysis was applied in the present work, with the main goal of evaluating global research on the topic of cardiac troponin in pediatric populations.

Methods

Publications about cardiac troponin and physical activity in pediatric populations were retrieved from the Social Sciences Citation Index (SSCI) and the Science Citation Index Expanded (SCIE) of the Web of Science Core Collection, and they were then analyzed. The study was able to identify the key bibliometric indicators, such as publications, keywords, authors, countries, institutions, and journals. For the analysis, VOSviewer, R-based Bibliometrix (4.2.2), and MapChart were used.

Results

Initially, 98 documents were identified; however, once inclusion and exclusion criteria were applied, the number of documents decreased to 88. The search yielded 79 original research articles and 9 reviews, almost all of which were published in the past 2 decades. The total number of citations (Nc) of the retrieved publications was 1,468, and the average number of citations per article (Na) was 16.68. In general, 508 authors were found to have participated in research about troponin; they were associated with 256 institutions, and their work was published in 65 different journals from around the world. The authors hailed from 30 countries and/or regions. The year 2022 was the most productive year for the publication of the selected documents. The bibliometric analysis provided information regarding levels of cooperation among authors and institutions. In fact, China, the United States, and England were the most productive nations, and the journal with the greatest number of publications on the topic was Pediatric Cardiology.

Summary

The number of publications and the trend line show that research on this topic has not yet reached a stage of maturity. There are referent investigators, countries, and institutions that have laid the foundations for subsequent studies on the analyzed topic.

High-sensitivity cardiac troponin I for cardiovascular risk stratification in apparently healthy individuals

Troponin I and T as cardiac-specific biomarkers are highly useful tools not only in the diagnosis of acute coronary syndromes but also as independent predictors of several other clinical conditions. High-sensitivity cardiac troponin (hs-cTn) assays allow the detection of considerably low concentrations of cardiac troponin in apparently healthy and asymptomatic individuals, being a candidate tool for cardiovascular risk stratification in the general population. A group of Greek experts summarized the bulk of evidence regarding the use of hs-cTnI as a predictor of cardiovascular events and mortality in apparently healthy individuals and its additive value on top of existing risk stratification methods. This document could serve as a guide for the incorporation of hs-cTnI as an additional risk stratification tool in cardiovascular prevention strategies in apparently healthy individuals.

High-sensitivity Troponin (hs-Tn) for Cardiovascular Risk Prognostication: A Systematic Review and Meta-analysis

BACKGROUND

Chronic low-grade inflammation is involved in coronary atherosclerosis progression whereas recent research efforts suggest that preventative methods should be tailored to the "residual inflammatory risk". As such, modalities for the early identification of the risk have to be investigated.

METHODS

We performed a systematic review and meta-analysis according to the PRISMA guidelines. Any study that presented the prognostic value of high sensitivity troponin (hs-cTn) of vascular inflammation in stable patients without known cardiac heart disease was considered to be potentially eligible. The Medline (PubMed) database was searched up to April 22, 2021. The main endpoint was the difference in c-index (Δ[c-index]) with the use of hs-cTn for major adverse cardiovascular events (MACEs), cardiovascular and all-cause mortality. We calculated I2 to test heterogeneity.

RESULTS

In total, 44 studies and 112,288 stable patients without known coronary heart disease were included in this meta-analysis. The mean follow-up duration of the whole cohort was 6.8 ± 1.1 years. 77,004 (68.5%) of the patients presented at low cardiovascular risk while 35,284 (31.5%) in high. The overall pooled estimate of Δ[c-index] for MACE was 1.4% (95%CI: 0.7-2.1, I2=0%) and for cardiovascular death 1.3% (95%CI: 0.3-2.3, I2=0%). Finally, the overall pooled estimate of Δ[c-index] for all-cause mortality was 3% (95%CI: 1.9-3.9, I2=86%), while high heterogeneity was observed between the studies.

CONCLUSION

The predictive usefulness of changes in hs-cTn measures in stable individuals with either high or low cardiovascular risk, demonstrates that assessing vascular inflammation in addition to clinical risk factors enhances risk prediction for cardiovascular events and allcause mortality. Further prospective studies are necessary to confirm these findings and assist clinical decision-making regarding the most optimal prevention strategy.

Optimizing the Clinical Use of High-Sensitivity Troponin Assays: A Review

Ischemic heart diseases (IHDs) remain a global health concern. Many IHD cases go undiagnosed due to challenges in the initial diagnostic process, particularly in cases of acute myocardial infarction (AMI). High-sensitivity cardiac troponin (hs-cTn) assays have revolutionized myocardial injury assessment, but variations in diagnostic cut-off values and population differences have raised challenges. This review addresses essential laboratory and clinical considerations for hs-cTn assays. Laboratory guidelines discuss the importance of establishing standardized 99th-percentile upper reference limits (URLs) considering factors such as age, sex, health status, and analytical precision. The reference population should exclude individuals with comorbidities like diabetes and renal disease, and rigorous selection is crucial. Some clinical guidelines emphasize the significance of sex-specific URL limits while others do not. They highlight the use of serial troponin assays for AMI diagnosis. In addition, timely reporting of accurate hs-cTn results is essential for effective clinical use. This review aims to provide a clearer understanding among laboratory professionals and clinicians on how to optimize the use of hs-cTn assays in clinical settings in order to ensure accurate AMI diagnosis and thus improve patient care and outcomes.

Diagnoses and Outcomes of Patients with Suspicion of Acute Coronary Syndrome and Raised High Sensitive Troponin I: A Single Center Study from Pakistan

Objectives  Troponins are classically raised in acute coronary syndrome (ACS) although other cardiovascular and non-cardiovascular causes are recognized. We aimed to see the association of high sensitivity (Hs) Troponin I values exceeding the sex-specific 99th percentile upper reference limit (URL) with diagnoses, emergency department (ED) outcomes, 30-day outcomes of admitted patients and predictors of ACS in both genders. Materials and Methods  A retrospective study of all patients presenting to the emergency department from January 2019 to April 2021 with suspicion of ACS and Hs-Troponin I values greater than the sex-specific 99th percentile URL. Statistical Analysis  SPSS version 24 was used, Pearson's chi-square tests, Fisher's exact test, Kruskal-Wallis test, Mann-Whitney U test, and odds ratios, including the 95% confidence intervals, for each characteristic were used for analysis. A p -value of < 0.05 was considered significant. Results  There were a total of 5,982 patients (3,031 males, 2,951 females), out of which 878 patients were admitted under the cardiology specialty. In patients who were admitted to the ward, mortality was higher in females (8.2%) with less than a 10-fold rise in Hs-Troponin I while similar in both genders (7.6%) in patients with Hs-troponin I greater than 10-fold of sex-specific 99th percentile URL. Raised low-density lipoprotein-cholesterol was a significant factor associated with 2.4 times higher odds of ACS. Conclusion  Women with Hs-Troponin values up to 10 times the URL, i.e., 15.6-160 ng/L have higher mortality than their male counterparts. LDL-cholesterol is a significant risk factor for ACS which should be controlled for its prevention.

Cardiac Troponin Release after Exercise in Healthy Young Athletes: A Systematic Review

Cardiac troponin (cTn) is a recognized marker used to assess damage to the heart muscle. Actual research has indicated that the levels of cTn increase after doing exercise in individuals who are in good health, and this is believed to be a result of a normal cellular process rather than a pathological one. The main goal of this study was to investigate the evidence of a postexercise release of cTn in child and adolescent athletes (6-17.9 years old) of different ages, sex, and sports disciplines. The Web of Science, MEDLINE, and Scopus databases were used to conduct the research up to March 2023. Three hundred and twenty-eight records were identified from the databases, however, only twenty-three studies were included in the review after being screened and quality-assessed by two independent authors. The gender, age of the participants, maturational status, and training level of the participants, the timing of sample collection, the exercise modality, and the number of participants with values above the cut-off reference were the data analyzed. Males, older young people, and individual sports seemed to have higher levels of serum cTn after practice exercise. Different methodologies, analyzers, and cut-off reference values make it difficult to compare the data among studies.

Sex Differences in Cardiac Troponin Trajectories Over the Life Course

BACKGROUND

Cardiac troponin concentrations are lower in women than men. We examined whether age- and risk factor-related changes in cardiac troponin over the life course differ by sex and if the trajectory of cardiac troponin was informative in respect of cardiovascular outcomes in women and men in the general population.

METHODS

In the Whitehall II cohort, high-sensitivity cardiac troponin I concentrations were measured on 3 occasions over a 15-year period. Using linear mixed-effects models, the sex-specific trajectories of cardiac troponin were evaluated, and the relationship with conventional cardiovascular risk factors determined. Using multistate joint models, the association between sex-specific trajectories of cardiac troponin and a composite outcome of nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death was evaluated.

RESULTS

In 2142 women and 5151 men (mean, 58±7 and 57±7 years of age, respectively), there were 177 (8.3%) and 520 (10.1%) outcome events, respectively, during a median follow-up of 20.9 (25th to 75th percentile, 15.8-21.3) years. Cardiac troponin concentrations were persistently lower in women than in men (median baseline concentration: 2.4 [25th to 75th percentile, 1.7-3.6] ng/L versus 3.7 [25th to 75th percentile, 2.6-5.8] ng/L, respectively, P<0.001), with women exhibiting a relatively larger increase with advancing age as compared with men (Pinteraction<0.001). Apart from age, a significant and divergent interaction with sex was found for the association between cardiac troponin and body mass index (BMI) (Pinteraction=0.008) and diabetes (Pinteraction=0.003). During follow-up, cardiac troponin concentrations were associated to the outcome in both women and men (adjusted hazard ratio per 2-fold difference [95% CI, 1.34 (1.17-1.52) and 1.30 (1.21-1.40), respectively], Pinteraction=0.752). The slope of cardiac troponin was significantly associated with the outcome in women, but not in men (adjusted hazard ratio [95% CI, 2.70 (1.01-7.33) and 1.31 (0.62-2.75), respectively], Pinteraction=0.250).

CONCLUSIONS

Trajectories of cardiac troponin differ between women and men in the general population, with differing associations to conventional risk factors and cardiovascular outcomes. Our findings highlight the importance of a sex-specific approach when serial cardiac troponin testing is applied for cardiovascular risk prediction.

Significance of Statin-Associated Muscle Symptoms and Its Impact on Patients Adherence and Outcomes

ABSTRACT

Statin-associated muscle symptoms (SAMS) are one of the most common side effects of statins. This study aimed to explore the significance of SAMS among statin users by comparing statin users with a control group. To achieve our aims, a propensity score matching the retrospective cohort study was conducted in a single center tertiary hospital. The statin muscle symptoms were assessed using the Proposed Statin Myalgia Index Score, whereas the patient's adherence to medications was evaluated using the Morisky Medication Adherence Scale-8. We included 743 patients in our study; of them, 64.9% were on statin, whereas the rest were controls (35.1%). After propensity score matching, patients on statin had significantly higher rates of SAMS (5.0%) compared with control (1.6%) (AOR = 3.209; 95% CI: 1.020-10.091). However, there was no significant difference between statin users and controls in medications nonadherence ( P -value = 0.820). Our analysis among statins users revealed that moderate-intensity (2.671; 95% CI: 1.691-3.310) and high-intensity (3.552; 95% CI: 2.190-4.129) statin therapy was significantly associated with SAMS. In addition, autoimmune diseases were significantly associated with SAMS occurrence (AOR = 32.301; 95% CI: 1.785-584.374). Also, patients on PPIs had significantly less occurrence of SAMS (AOR = 0.145; 95% CI: 0.044-0.483), whereas patients on antiepileptic drugs had significantly higher SAMS occurrence (AOR = 72.337; 95% CI: 2.649-1975.201). Regarding MACE among statin users, there was no significant difference in the 1-year or 5-year MACE rate between statin users and controls. Our study suggests that SAMS are significant among statin users and must be addressed by health care providers to ensure that patients are still adherent to their medications and hence protected against cardiac events.

Effect of Dexamethasone on Myocardial Injury After Total Knee Arthroplasty: A Substudy of the Randomized Clinical DEX-2-TKA Trial

BACKGROUND

Myocardial injury after noncardiac surgery (MINS) carries a high postoperative mortality. In this preplanned, subgroup analysis of the randomized DEX-2-TKA Trial, we investigated the effect of dexamethasone versus placebo on the concentration of cardiac troponin I and T (TnI and TnT) on the first postoperative morning after total knee arthroplasty. In addition, frequency of MINS, myocardial infarction, and major adverse cardiovascular events where evaluated.

METHODS

We included 290 patients who received either 24 mg of dexamethasone intravenously (given perioperatively) or placebo. Blood samples were analyzed as either TnI or T depending on trial site.

RESULTS

A total of 236 samples were eligible for analysis of TnI and 38 samples for TnT on the first postoperative morning. The median (IQR) TnI concentration was 4.6 ng/L (0-7.2 ng/L) in the dexamethasone group and 4.5ng/l (0-7.0 ng/L) in the placebo group (P = .96) on the first postoperative morning. The median TnT was 9 ng/L (6-11 ng/L) in the dexamethasone group and 8 ng/L (5-10 ng/L) in the placebo group (P = .68). The frequencies of MINS, myocardial infarction, and major adverse cardiovascular events were similar in the compared groups, but these analyses were underpowered.

CONCLUSION

We found no effect of dexamethasone on postoperative concentration of troponin I or T on the first postoperative morning after total knee arthroplasty.

Prognostic Value of High-Sensitivity Cardiac Troponin in Women

High-sensitivity cardiac troponin assays have become the gold standard for diagnosing acute and chronic myocardial injury. The detection of troponin levels beyond the 99th percentile is included in the fourth universal definition of myocardial infarction, specifically recommending the use of sex-specific thresholds. Measurable concentrations below the proposed diagnostic thresholds have been shown to inform prognosis in different categories of inpatients and outpatients. However, clinical investigations from the last twenty years have yielded conflicting results regarding the incremental value of using different cut-offs for men and women. While advocates of a sex-specific approach claim it may help reduce gender bias in cardiovascular medicine, particularly in acute coronary syndromes, other groups question the alleged incremental diagnostic and prognostic value of sex-specific thresholds, ultimately asserting that less is more. In the present review, we aimed to synthesize our current understanding of sex-based differences in cardiac troponin levels and to reappraise the available evidence with regard to (i) the prognostic significance of sex-specific diagnostic thresholds of high-sensitivity cardiac troponin assays compared to common cut-offs in both men and women undergoing cardiovascular disease risk assessment, and (ii) the clinical utility of high-sensitivity cardiac troponin assays for cardiovascular disease prevention in women.

High-sensitivity troponins for outcome prediction in the general population: a systematic review and meta-analysis

BACKGROUND

High-sensitivity (hs) assays allow to measure cardiac troponin T and I (cTnT/I) even in healthy individuals. The higher hs-cTn values, the higher the ongoing cardiomyocyte damage, and then reasonably the risk of developing symptomatic cardiac disease.

METHODS

We retrieved all studies evaluating the prognostic value of hs-cTnT or I in the general population. We calculated pooled hazard ratio (HR) values for all-cause and cardiovascular death, cardiovascular events and heart failure (HF) hospitalization.

RESULTS

We included 24 studies for a total of 203,202 subjects; 11 studies assessed hs-cTnT and 14 hs-cTnI. One standard deviation (SD) increase in baseline hs-cTn was associated with a 23% higher risk of all-cause death (HR 1.226, 95% CI 1.083-1.388, p<0.001, I²=88.5%); all these studies measured hs-cTnI. In an exploratory analysis on 3 studies with 25,760 subjects, hs-cTn predicted cardiovascular death (HR 1.822, 95% CI 1.241-2.674, p=0.002, I²=87.2%). After synthesizing 9 studies with 58,565 subjects, hs-cTn predicted cardiovascular events (HR 1.328, 95% CI 1.167-1.513, p<0.001, I²=93.8%). Both hs-cTnT (HR 1.627, 95% CI 1.145-2.311, p<0.001) and hs-cTnI (HR 1.260, 95% CI 1.115-1.423, p<0.001; p for interaction <0.001). Furthermore, in 10 studies with 61,467 subjects, hs-cTn predicted HF hospitalization (HR 1.493, 95% CI 1.368-1.630, p<0.001, I²=76.6%). Both hs-cTnT (HR 1.566, 95% CI 1.303-1.883, p<0.001) and hs-cTnI (HR 1.467, 95% CI 1.321-1.628, p<0.001) were associated with HF hospitalization (p for interaction <0.001).

CONCLUSIONS

hs-cTn values hold strong prognostic value in subjects from the general population, predicting the risk of all-cause and cardiovascular mortality, cardiovascular events, and HF hospitalization.

Use of high-sensitivity cardiac troponins in the emergency department for the early rule-in and rule-out of acute myocardial infarction without persistent ST-segment elevation (NSTEMI) in Italy

Serial measurements of cardiac troponin are recommended by international guidelines to diagnose myocardial infarction (MI) since 2000. However, some relevant differences exist between the three different international guidelines published between 2020 and 2021 for the management of patients with chest pain and no ST-segment elevation. In particular, there is no agreement on the cut-offs or absolute change values to diagnose non-ST-segment elevation MI (NSTEMI). Other controversial issues concern the diagnostic accuracy and cost-effectiveness of cut-off values for the most rapid algorithms (0 h/1 h or 0 h/2 h) to rule-in and rule-out NSTEMI. Finally, another important point is the possible differences between demographic and clinical characteristics of patients enrolled in multicenter trials compared to those routinely admitted to the Emergency Department in Italy. The Study Group of Cardiac Biomarkers, supported by the Italian Scientific Societies Società Italiana di Biochimica Clinica, Italian Society of the European Ligand Assay Society, and Società Italiana di Patolgia Clinica e Medicina di Laboratorio decided to revise the document previously published in 2013 about the management of patients with suspected NSTEMI, and to provide some suggestions for the use of these biomarkers in clinical practice, with a particular focus on the Italian setting.

Sex Differences in Cardiac Troponin I and T and the Prediction of Cardiovascular Events in the General Population

BACKGROUND

Cardiac troponin concentrations differ in women and men, but how this influences risk prediction and whether a sex-specific approach is required is unclear. We evaluated whether sex influences the predictive ability of cardiac troponin I and T for cardiovascular events in the general population.

METHODS

High-sensitivity cardiac troponin (hs-cTn) I and T were measured in the Generation Scotland Scottish Family Health Study of randomly selected volunteers drawn from the general population between 2006 and 2011. Cox-regression models evaluated associations between hs-cTnI and hs-cTnT and the primary outcome of cardiovascular death, myocardial infarction, or stroke.

RESULTS

In 19 501 (58% women, mean age 47 years) participants, the primary outcome occurred in 2.7% (306/11 375) of women and 5.1% (411/8126) of men during the median follow-up period of 7.9 (IQR, 7.1-9.2) years. Cardiac troponin I and T concentrations were lower in women than men (P < 0.001 for both), and both were more strongly associated with cardiovascular events in women than men. For example, at a hs-cTnI concentration of 10 ng/L, the hazard ratio relative to the limit of blank was 9.7 (95% CI 7.6-12.4) and 5.6 (95% CI 4.7-6.6) for women and men, respectively. The hazard ratio for hs-cTnT at a concentration of 10 ng/L relative to the limit of blank was 3.7 (95% CI 3.1-4.3) and 2.2 (95% CI 2.0-2.5) for women and men, respectively.

CONCLUSIONS

Cardiac troponin concentrations differ in women and men and are stronger predictors of cardiovascular events in women. Sex-specific approaches are required to provide equivalent risk prediction.

Determinants of Interindividual Variation in Exercise-Induced Cardiac Troponin I Levels

Background Postexercise cardiac troponin levels show considerable interindividual variations. This study aimed to identify the major determinants of this postexercise variation in cardiac troponin I (cTnI) following 3 episodes of prolonged high-intensity endurance exercise. Methods and Results Study subjects were recruited among prior participants in a study of recreational cyclists completing a 91-km mountain bike race in either 2013 or 2014 (first race). In 2018, study participants completed a cardiopulmonary exercise test 2 to 3 weeks before renewed participation in the same race (second race). Blood was sampled before and at 3 and 24 hours following all exercises. Blood samples were analyzed using the same Abbot high-sensitivity cTnI STAT assay. Fifty-nine individuals (aged 50±9 years, 13 women) without cardiovascular disease were included. Troponin values were lowest before, highest at 3 hours, and declining at 24 hours. The largest cTnI difference was at 3 hours following exercise between the most (first race) (cTnI: 200 [87-300] ng/L) and the least strenuous exercise (cardiopulmonary exercise test) (cTnI: 12 [7-23] ng/L; P<0.001). The strongest correlation between troponin values at corresponding times was before exercise (r=0.92, P<0.0001). The strongest correlations at 3 hours were between the 2 races (r=0.72, P<0.001) and at 24 hours between the cardiopulmonary exercise test and the second race (r=0.83, P<0.001). Participants with the highest or lowest cTnI levels showed no differences in race performance or baseline echocardiographic parameters. Conclusions The variation in exercise-induced cTnI elevation is largely determined by a unique individual cTnI response that is dependent on the duration of high-intensity exercise and the timing of cTnI sampling. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02166216.

Pilot project to study the association of troponin I with cardiovascular events in the population of Russian region

Aim. As part of a pilot study, to investigate the potential significance of cardiac troponin I (cTnI) in assessing the risk of cardiovascular diseases (CVD) in general population aged 35-64 years of one of the regions from the ESSE-RF study.

Material and methods. The study is based on the ESSE-RF observational prospective study using a sample from one Russian region. The analysis included socio-demographic variables, risk factors, history of CVD. The cTnI level was measured from November to December 2021 in serum samples stored at -70° C using high sensitivity chemiluminescent microparticle immunoassay using Architect Stat High Sensitivity Troponin I (Abbott) reagents on an Architect i2000SR immunoassay analyzer (Abbott, Abbot Park IL USA). The endpoints were hard (cardiovascular death and myocardial infarction) and composite endpoints (cardiovascular death, new cases of myocardial infarction, stroke, coronary artery disease and revascularization). The median follow-up was 5,5 years. In total, the analysis included 1120 people aged 35-64 years.

Results. Analysis of the associations between Systematic Coronary Risk Evaluation (SCORE) and cTnI showed a significant difference in risk stratification for these two parameters. In women from cTnI-related high-risk category for cardiovascular events (CVE), there were no endpoints at all. In men of moderate and high risk, the proportion of endpoints increases with increasing cTnI-related risk. The survival curves corresponding to first 3 quintiles of cTnI risk distribution did not diverge, and, therefore, the number of CVEs in these groups did not differ. At the same time, the curves corresponding to 4th and 5th quintiles significantly differed from the first 3 quintiles, which indicates a higher CVE risk in subjects from these groups (p<0,001). Considering that there were only 3 endpoints in cTnI-related high-risk group, a survival analysis was performed for low-risk versus moderate-high risk. The curves obtained diverge significantly (p=0.006). Cox proportional hazards models were analyzed to assess the relationship between the cTnI level and endpoints. It was shown that cTnI itself or its logarithm is significantly associated with hard and composite endpoints. The cTnI cut-off point of 12/10 pg/ml (males/females) was associated with hard endpoint, and 6/4 pg/ml — with composite one. It should be noted that the recommended cut-off point of 6/4 pg/ml is close to the upper quartile of cTnI distribution in the European population. For the Russian population, the upper quartile corresponds to cTnI level of 3,5/2,1 pg/ml, which indicates the need to reduce the critical cTnI values in Russia. To assess risk reclassification, Cox models were analyzed using the Net Reclassification Index (NRI), as well as NRIsurvival for survival analysis. For categorical variables, the NRIcategorial was used. Both methods of including cTnI in the model significantly improve the risk classification of severe endpoints in men.

Conclusion. The results obtained confirm the need to lower the threshold values for predicting combined endpoints, in particular, in Russian men. cTnl has an independent effect on CVE risk and its addition to SCORE improves the prediction of CVEs among men. However, the data obtained are preliminary and require clarification sing larger sample. At the same time, it is obvious that the determination of cТnI level can play a significant role in cardiovascular risk assessment and be an unfavorable prognosis marker among Russian population.

Diagnostic algorithms for non-ST-segment elevation myocardial infarction: open issues

The use of serial measurement of cardiac troponin (cTn) is recommended by international guidelines for the diagnosis of myocardial infarction (MI) since 2000. This article focuses on factors influencing temporal changes in high-sensitive cTn (hs)-cTn and the impact of these factors on the diagnosis of non-ST-segment elevation MI (NSTEMI). The recommendations proposed by three different international guidelines published in 2020-2021 for the management of acute coronary syndromes (ACS) in patients presenting without persistent ST-segment elevation (NSTE) show some discrepancies. In particular, there is no agreement among these guidelines about cut-off or absolute change values to be used for the rule-in, especially regarding the use of sex-specific cut-off values. Furthermore, there are no sufficient evidences on the diagnostic accuracy and cost effectiveness related to cut-off values suggested for algorithms to be used by some hs-cTnI methods.

High sensitivity troponin, analytical advantages, clinical benefits and clinical challenges - An update

The measurement of cardiac troponin (cTn) by a high sensitivity method now represents the standard method for cTn measurement in the laboratory. High sensitivity method are not measuring a novel form of troponin but have undergone methodological improvement in assay sensitivity to allow both very low level detection and repeat measurements at low levels with very low degrees of analytical imprecision. The methods identify additional patients with myocardial injury who would benefit from evidence-based interventions. Rapid predictive algorithms utilising measurement on admission as well as short sampling periods (1-2 h) allow much more rapid categorisation of patients to appropriate clinical pathways. The shift in the diagnosis from traditional "cardiac enzymes" to troponin based on the 99th percentile has accounted for the majority of the detection of myocardial injury in patients without acute coronary syndromes. These patients have a worse prognosis irrespective of the underlying cause of their hospital admission. The appropriate management strategy in this group, beyond managing the underlying problem, remains to be defined. Measurement of cTn in otherwise asymptomatic individuals may have a role for patient selection for preventive treatment or for patients monitoring. Clinical trials in this area are awaited.

Cardiac troponins: are there any differences between T and I?

The most recent international guidelines recommend the measurement of cardiac troponin I (cTnI) and cardiac troponin T (cTnT) using high-sensitivity methods (hs-cTn) for the detection of myocardial injury and the differential diagnosis of acute coronary syndromes. Myocardial injury is a prerequisite for the diagnosis of acute myocardial infarction, but also a distinct entity. The 2018 Fourth Universal Definition of Myocardial Infarction states that myocardial injury is detected when at least one value above the 99th percentile upper reference limit is measured in a patient with high-sensitivity methods for cTnI or cTnT. Not infrequently, increased hs-cTnT levels are reported in patients with congenital or chronic neuromuscular diseases, while the hs-cTnI values are often in the normal range. Furthermore, some discrepancies between the results of laboratory tests for the two troponins are occasionally found in individuals apparently free of cardiac diseases, and also in patients with cardiac diseases. In this review article, authors discuss the biochemical, pathophysiological and analytical mechanisms which may cause discrepancies between hs-cTnI and hs-cTnT test results.

Clinical relevance of biological variation of cardiac troponins

The high-sensitivity immunoassays for cardiac troponin I (hs-cTnI) and cardiac troponin T (hs-cTnT) are recommended by all the most recent international guidelines as gold standard laboratory methods for the detection of myocardial injury and diagnosis of acute myocardial infarction (AMI). In this review article, the Authors aimed at discussing the relevant biochemical, physiological, and clinical issues related to biological variability of cTnI and cTnT. Cardiac troponins, measured with hs-cTn methods, show a better clinical profile than the other cardio-specific biomarkers (such as the natriuretic peptides, BNP and NT-proBNP). In particular, the hs-cTn methods are characterized by a low intra-individual index of variation (<0.6) and reduced analytical imprecision (about 5% CV) at the clinical cut-off value (i.e., the 99th percentile URL value). Moreover, recent studies have reported that differences between two hs-cTn measured values (RCV) >30% can be considered statistically significant. These favourable biological characteristics and analytical performance of hs-cTn methods significantly improved the accuracy in the diagnostic process of acute coronary syndromes (ACS) in patients admitted to emergence department. In addition, several studies have demonstrated the clinical usefulness of cardiovascular risk evaluation with hs-cTn methods in some groups of patients with clinical conditions at high cardiovascular risk (such as systemic hypertension, severe obesity, diabetes mellitus, renal insufficiency, and chronic obstructive pulmonary disease). However, screening programs in the general population with hs-cTn methods for cardiovascular risk stratification require further investigation to define the optimal target populations, timing of measurement, and preventive interventions.

High-sensitivity methods for cardiac troponins: The mission is not over yet

The measurement of cardiac troponin (cTn) is recommended by all guidelines as the gold standard for the differential diagnosis of Acute Coronary Syndromes. The aim of this review is to discuss in details some key issues regarding both analytical and clinical characteristics of the high-sensitivity methods for cTn (hs-cTn), which are still considered controversial or unresolved. In particular, the major clinical concern regarding hs-cTn methods is the difficulty to differentiate the pathophysiological mechanism responsible for biomarker release from cardiomyocytes after reversible or irreversible injury, respectively. Indeed, recent experimental and clinical studies have demonstrated that different circulating forms of cTnI and cTnT can be respectively measured in plasma samples of patients with reversible or irreversible myocardial injury. Accordingly, a new generation of hs-Tn methods should be set up, based on immunometric immunoassays or chromatographic techniques, specific for circulating peptide forms more characteristics for reversible or irreversible myocardial injury. It is conceivable that this new generation of hs-cTn methods will complete the mission regarding the laboratory tests for specific cardiac biomarkers, started more than 20 years ago, which has already revolutionized the diagnosis, prognosis and management of patients with cardiac diseases.

Evidence on clinical relevance of cardiovascular risk evaluation in the general population using cardio-specific biomarkers

In recent years, the formulation of some immunoassays with high-sensitivity analytical performance allowed the accurate measurement of cardiac troponin I (cTnI) and T (cTnT) levels in reference subjects. Several studies have demonstrated the association between the risk of major cardiovascular events and cardiac troponin concentrations even for biomarker values within the reference intervals. High-sensitivity cTnI and cTnT methods (hs-cTn) enable to monitor myocardial renewal and remodelling, and to promptly identify patients at highest risk ofheart failure. An early and effective treatment of individuals at higher cardiovascular risk may revert the initial myocardial remodelling and slow down heart failure progression. Specific clinical trials should be carried out to demonstrate the efficacy and efficiency of the general population screening by means of cost-benefit analysis, in order to better identify individuals at higher risk for heart failure (HF) progression with hs-cTn methods.

Biomarkers in predicting cardiovascular risk: new prospects of troponin I

Risk stratification is an important aspect of effective control of cardiovascular diseases. Risk scores based on conventional risk factors did not solve the stratification problem completely due to a number of factors. One way to increase the accuracy of predicting cardiovascular risk may be to supplement conventional scores with cardiovascular biomarkers. Cardiac troponins are the most reliable cardiovascular biomarkers in the diagnosis of acute myocardial infarction. However, recent studies have shown that they have the potential to use as an addition to cardiovascular risk stratification scores. Cardiac troponins meet the requirements for new biomarkers: cardiospecificity, prognostic value, change in levels in response to risk reduction actions, evidence value, economic efficiency. A large number of population studies demonstrate the association of elevated levels of cardiac troponin I with adverse cardiovascular events. To assess the prospects of supplementing conventional risk scores with new biomarkers, including troponin I, the study of the role of biomarkers in cardiovascular risk prediction in men and women of working age is started in Russia.

Two-step magnetic bead-based (2MBB) techniques for immunocapture of extracellular vesicles and quantification of microRNAs for cardiovascular diseases: A pilot study

Extracellular vesicles (EVs) have attracted increasing attention because of their potential roles in various biological processes and medical applications. However, isolation of EVs is technically challenging mainly due to their small and heterogeneous size and contaminants that are often co-isolated. We have thus designed a two-step magnetic bead-based (2MBB) method for isolation a subset of EVs as well as their microRNAs from samples of a limited amount. The process involves utilizing magnetic beads coated with capture molecules that recognize EV surface markers, such as CD63. Captured EVs could be eluted from beads or lyzed directly for subsequent analysis. In this study, we used a second set of magnetic beads coated with complementary oligonucleotides to isolate EV-associated microRNAs (EV-miRNAs). The efficiencies of 2MBB processes were assessed by reverse transcription-polymerase chain reaction (RT-PCR) with spiked-in exogenous cel-miR-238 molecules. Experimental results demonstrated the high efficiency in EV enrichment (74 ± 7%, n = 4) and miRNA extraction (91 ± 4%, n = 4). Transmission electron micrographs (TEM) and nanoparticle tracking analysis (NTA) show that captured EVs enriched by 2MBB method could be released and achieved a higher purity than the differential ultracentrifugation (DUC) method (p < 0.001, n = 3). As a pilot study, EV-miR126-3p and total circulating cell-free miR126-3p (cf-miR126-3p) in eight clinical plasma samples were measured and compared with the level of protein markers. Compared to cf-miR126-3p, a significant increase in correlations between EV-miR126-3p and cardiac troponin I (cTnI) and N-terminal propeptide of B-type natriuretic peptide (NT-proBNP) was detected. Furthermore, EV-miR126-3p levels in plasma samples from healthy volunteers (n = 18) and high-risk cardiovascular disease (CVD) patients (n = 10) were significantly different (p = 0.006), suggesting EV-miR126 may be a potential biomarker for cardiovascular diseases. 2MBB technique is easy, versatile, and provides an efficient means for enriching EVs and EV-associated nucleic acid molecules.

High-Sensitivity Troponin I and Incident Coronary Events, Stroke, Heart Failure Hospitalization, and Mortality in the ARIC Study

BACKGROUND

We assessed whether plasma troponin I measured by a high-sensitivity assay (hs-TnI) is associated with incident cardiovascular disease (CVD) and mortality in a community-based sample without prior CVD.

METHODS

ARIC study (Atherosclerosis Risk in Communities) participants aged 54 to 74 years without baseline CVD were included in this study (n=8121). Cox proportional hazards models were constructed to determine associations between hs-TnI and incident coronary heart disease (CHD; myocardial infarction and fatal CHD), ischemic stroke, atherosclerotic CVD (CHD and stroke), heart failure hospitalization, global CVD (atherosclerotic CVD and heart failure), and all-cause mortality. The comparative association of hs-TnI and high-sensitivity troponin T with incident CVD events was also evaluated. Risk prediction models were constructed to assess prediction improvement when hs-TnI was added to traditional risk factors used in the Pooled Cohort Equation.

RESULTS

The median follow-up period was ≈15 years. Detectable hs-TnI levels were observed in 85% of the study population. In adjusted models, in comparison to low hs-TnI (lowest quintile, hs-TnI ≤1.3 ng/L), elevated hs-TnI (highest quintile, hs-TnI ≥3.8 ng/L) was associated with greater incident CHD (hazard ratio [HR], 2.20; 95% CI, 1.64-2.95), ischemic stroke (HR, 2.99; 95% CI, 2.01-4.46), atherosclerotic CVD (HR, 2.36; 95% CI, 1.86-3.00), heart failure hospitalization (HR, 4.20; 95% CI, 3.28-5.37), global CVD (HR, 3.01; 95% CI, 2.50-3.63), and all-cause mortality (HR, 1.83; 95% CI, 1.56-2.14). hs-TnI was observed to have a stronger association with incident global CVD events in white than in black individuals and a stronger association with incident CHD in women than in men. hs-TnI and high-sensitivity troponin T were only modestly correlated ( r=0.47) and were complementary in prediction of incident CVD events, with elevation of both troponins conferring the highest risk in comparison with elevation in either one alone. The addition of hs-TnI to the Pooled Cohort Equation model improved risk prediction for atherosclerotic CVD, heart failure, and global CVD.

CONCLUSIONS

Elevated hs-TnI is strongly associated with increased global CVD incidence in the general population independent of traditional risk factors. hs-TnI and high-sensitivity troponin T provide complementary rather than redundant information.

True 99th centile of high sensitivity cardiac troponin for hospital patients: prospective, observational cohort study

OBJECTIVE

To determine the distribution, and specifically the true 99th centile, of high sensitivity cardiac troponin I (hs-cTnI) for a whole hospital population by applying the hs-cTnI assay currently used routinely at a large teaching hospital.

DESIGN

Prospective, observational cohort study.

SETTING

University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom, between 29 June 2017 and 24 August 2017.

PARTICIPANTS

20 000 consecutive inpatients and outpatients undergoing blood tests for any clinical reason. Hs-cTnI concentrations were measured in all study participants and nested for analysis except when the supervising doctor had requested hs-cTnI for clinical reasons.

MAIN OUTCOME MEASURES

Distribution of hs-cTnI concentrations of all study participants and specifically the 99th centile.

RESULTS

The 99th centile of hs-cTnI for the whole population was 296 ng/L compared with the manufacturer's quoted level of 40 ng/L (currently used clinically as the upper limit of normal; ULN). Hs-cTnI concentrations were greater than 40 ng/L in one in 20 (5.4%, n=1080) of the total population. After excluding participants diagnosed as having acute myocardial infarction (n=122) and those in whom hs-cTnI was requested for clinical reasons (n=1707), the 99th centile was 189 ng/L for the remainder (n=18 171). The 99th centile was 563 ng/L for inpatients (n=4759) and 65 ng/L for outpatients (n=9280). Patients from the emergency department (n=3706) had a 99th centile of 215 ng/L, with 6.07% (n=225) greater than the recommended ULN. 39.02% (n=48) of all patients from the critical care units (n=123) and 14.16% (n=67) of all medical inpatients had an hs-cTnI concentration greater than the recommended ULN.

CONCLUSIONS

Of 20 000 consecutive patients undergoing a blood test for any clinical reason at our hospital, one in 20 had an hs-cTnI greater than the recommended ULN. These data highlight the need for clinical staff to interpret hs-cTnI concentrations carefully, particularly when applying the recommended ULN to diagnose acute myocardial infarction, in order to avoid misdiagnosis in the absence of an appropriate clinical presentation.

TRIAL REGISTRATION

Clinicaltrials.gov NCT03047785.

Prognostication of clinical outcomes in diabetes mellitus: Emerging role of cardiac biomarkers

Type 2 diabetes mellitus (T2DM) remains substantial health problem and one of the most prevalent metabolic diseases worldwide. The impact of T2DM on CV mortality and morbidity is embedded through a nature evolution of the disease and is modulated by numerous risk factors, such as hypertension, obesity, dyslipidemia. There is large body of evidence regarding use of the cardiac biomarkers to risk stratification at higher CV risk individuals who belongs to general population and cohort with established CV disease. Although T2DM patients have higher incidence of cardiac and vascular complications than the general population, whether cardiac biomarkers would be effective to risk stratification of the T2DM is not fully understood. The aim of the review is to summarize our knowledge regarding clinical implementation of cardiac biomarkers in risk assessment for T2DM patients. The role of natriuretic peptides, soluble ST2, galectin-3, growth differentiation factor-15, and cardiac troponins are widely discussed.

Prognostic implications of detectable cardiac troponin I below the 99th percentile in patients admitted to an emergency department without acute coronary syndrome

Background:

Detectable troponin below the 99th percentile may reflect an underlying cardiac abnormality which might entail prognostic consequences. This study aimed to investigate the prognosis of patients admitted to an emergency department (ED) with detectable troponin below the 99th percentile reference limit who did not present with an acute coronary syndrome (ACS).

Methods:

We analysed the clinical data of all consecutive patients admitted to the ED during the years 2012 and 2013 in whom cardiac troponin was requested by the attending clinician (cTnI Ultra Siemens, Advia Centaur). Patients with troponin below the 99th percentile of the reference population (40 ng/L) and who did not have a diagnosis of ACS were selected, and their mortality was evaluated in a 2-year follow-up.

Results:

A total of 2501 patients had a troponin level below the reference limit, with 43.9% of those showing detectable levels (>6 ng/L and <40 ng/L). Patients with detectable levels were elderly and had a higher prevalence of cardiovascular history and more comorbidities. The total mortality in the 2-year follow-up was 12.4% in patients with detectable troponin and 4.5% in patients with undetectable troponin (p<0.001). In the Cox multivariate regression analysis, the detectable troponin was an independent marker of mortality at 2 years (HR 1.62, 95% CI 1.07–2.45, p=0.021).

Conclusions:

Detectable troponin I below the 99th percentile is associated with higher mortality risk at 2-year follow-up in patients admitted to the ED who did not present with ACS.

Evaluating Rapid Rule-out of Acute Myocardial Infarction Using a High-Sensitivity Cardiac Troponin I Assay at Presentation

BACKGROUND

Low concentrations of cardiac troponin (cTn) have been recommended for rapid rule-out of acute myocardial infarction (AMI). We examined the Beckman Coulter Access high-sensitivity cardiac troponin I (hs-cTnI) assay to identify a single test threshold that can safely rule out AMI.

METHODS

This analysis used stored samples collected in 2 prospective observational studies. In all, 1871 patients presenting to a tertiary emergency department with symptoms of acute coronary syndrome had blood taken for measurement of cTnI on presentation. The endpoint was type 1 myocardial infarction (T1MI). Sensitivity and negative predictive value (NPV) were calculated for hs-cTnI values below the 99th percentile.

RESULTS

Ninety-eight patients had T1MI (5.2%), and 638 (34.1%) patients had an hs-cTnI &lt;2 ng/L (limit of detection), with sensitivity of 99.0% (95% CI, 94.4%–100%) and NPV of 99.8% (95% CI, 99.1%–100%). No hs-cTnI value above a concentration of 2 ng/L achieved sensitivity of 99%. However, an NPV of 99.5% was achieved at values &lt;6 ng/L. A cutoff &lt;6 ng/L enabled 1475 (78.8%) patients to be ruled out on presentation with sensitivity of 93.9% (95% CI, 87.1%–97.7%).

CONCLUSIONS

A single baseline cTn &lt;2 ng/L measured with the Access hs-cTnI assay performed well for rule-out of AMI. This cutoff concentration identified 99% of patients with AMI and could reduce the number of patients requiring lengthy assessment. A cutoff of &lt;6 ng/L yielded a high NPV but missed more cases of AMI than would be acceptable to clinicians.

Relative Prognostic Value of Cardiac Troponin I and C-Reactive Protein in the General Population (from the Nord-Trøndelag Health [HUNT] Study)

C-reactive protein and cardiac troponin I measured with high-sensitivity assays (high-sensitivity C-reactive protein [hs-CRP] and high-sensitivity troponin I [hs-TnI]) have been associated with risk of fatal and nonfatal cardiovascular events in the general population. The relative prognostic merits of hs-CRP and hs-TnI, and whether these markers of inflammation and subclinical myocardial injury provide incremental information to established cardiovascular risk prediction models, remain unclear. hs-CRP and hs-TnI were measured in 9,005 participants from the prospective observational Nord-Trøndelag Health (HUNT) study. All study subjects were free from known cardiovascular disease at baseline. During a median follow-up period of 13.9 years, 733 participants reached the composite end point of hospitalization for acute myocardial infarction or heart failure, or cardiovascular death. In adjusted models, increased hs-TnI concentrations (>10 ng/L for women and >12 ng/L for men) were associated with the incidence of the composite end point (hazard ratio 3.61, 95% confidence interval [CI] 2.89 to 4.51]), whereas the risk associated with increased hs-CRP concentrations (>3 mg/L for both genders) appeared to be weaker (HR 1.71, 95% CI 1.40 to 2.10). The addition of hs-TnI to established cardiovascular risk prediction models led to a net reclassification improvement of 0.35 (95% CI 0.27 to 0.42), superior to that of hs-CRP (0.21, 95% CI 0.13 to 0.28). The prognostic accuracy of hs-TnI, assessed by C-statistics, was significantly greater than that of hs-CRP (0.753, 95% CI 0.735 to 0.772, vs 0.644, 95% CI 0.625 to 0.663). In conclusion, in subjects from the general population without a history of cardiovascular disease, hs-TnI provides prognostic information superior to that provided by hs-CRP and may therefore be a preferred marker for targeted prevention.

High sensitivity troponins in contemporary cardiology practice: are we turning a corner?

INTRODUCTION

Troponin is considered to be the gold standard biomarker for ruling out MI. There has been a drive to improve the diagnostic speed, and as such the high sensitivity cardiac troponin (hs-cTn) assays have been introduced into clinical practice and are now part of international guidelines. Their novel value in clinical practice more generally is becoming apparent. Areas covered: In this review we will evaluate the evidence for the use of hs-cTn assays in clinical practice, the issues with the assay and how the hs-cTn can be utilized in the future as a biomarker of cardiovascular risk. Expert commentary: The use of the hs-cTn assays as a 'rule out' test for MI is compelling, as a 'rule in' there are significant issues relating the specificity of the assay for MI. The future of the assay may lie in population screening and risk modeling.

High-Sensitivity Cardiac Troponin Concentration and Risk of First-Ever Cardiovascular Outcomes in 154,052 Participants

BACKGROUND

High-sensitivity assays can quantify cardiac troponins I and T (hs-cTnI, hs-cTnT) in individuals with no clinically manifest myocardial injury.

OBJECTIVES

The goal of this study was to assess associations of cardiac troponin concentration with cardiovascular disease (CVD) outcomes in primary prevention studies.

METHODS

A search was conducted of PubMed, Web of Science, and EMBASE for prospective studies published up to September 2016, reporting on associations of cardiac troponin concentration with first-ever CVD outcomes (i.e., coronary heart disease [CHD], stroke, or the combination of both). Study-specific estimates, adjusted for conventional risk factors, were extracted by 2 independent reviewers, supplemented with de novo data from PROSPER (Pravastatin in Elderly Individuals at Risk of Vascular Disease Study), then pooled by using random effects meta-analysis.

RESULTS

A total of 28 relevant studies were identified involving 154,052 participants. Cardiac troponin was detectable in 80.0% (hs-cTnI: 82.6%; hs-cTnT: 69.7%). In PROSPER, positive associations of log-linear shape were observed between hs-cTnT and CVD outcomes. In the meta-analysis, the relative risks comparing the top versus the bottom troponin third were 1.43 (95% confidence interval [CI]: 1.31 to 1.56) for CVD (11,763 events), 1.67 (95% CI: 1.50 to 1.86) for fatal CVD (7,775 events), 1.59 (95% CI: 1.38 to 1.83) for CHD (7,061 events), and 1.35 (95% CI: 1.23 to 1.48) for stroke (2,526 events). For fatal CVD, associations were stronger in North American studies (p = 0.010) and those measuring hs-cTnT rather than hs-cTnI (p = 0.027).

CONCLUSIONS

In the general population, high cardiac troponin concentration within the normal range is associated with increased CVD risk. This association is independent of conventional risk factors, strongest for fatal CVD, and applies to both CHD and stroke.

Low Plasma Testosterone Is Associated With Elevated Cardiovascular Disease Biomarkers

BACKGROUND

The relation between testosterone (T) plasma concentration and cardiovascular (CV) risk is unclear, with evidence supporting increased risk in men with low and high T levels. Few studies have assessed CV risk as a function of plasma T levels using objective biomarkers.

AIM

To determine the relation between T levels and high-sensitivity CV risk biomarkers.

METHODS

Ten thousand forty-one male patients were identified in the database of a commercial clinical laboratory performing biomarker testing. Patients were grouped by total T concentration and associations with the following biomarkers were determined: cardiac troponin I (cTnI), endothelin-1 (ET-1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-17A, N-terminal pro-B-type natriuretic peptide (NTproBNP), high-density lipoprotein (HDL) cholesterol, high-sensitivity C-reactive protein (hs-CRP), hemoglobin A_1c (HbA_1c), and leptin.

OUTCOMES

Association of CV risk markers with levels of T in men.

RESULTS

The median age of the cohort was 58 years (interquartile range = 48-68), and the median plasma T level was 420 ng/dL (interquartile range = 304-565); T levels did not vary with patient age. An inverse relation between plasma T levels and CV risk was observed for 9 of 10 CV markers: cTnI, ET-1, IL-6, TNF-α, NTproBNP, HDL cholesterol, hs-CRP, HbA_1c, and leptin. Even after adjusting for age, body mass index, HbA_1c, hs-CRP, and HDL cholesterol levels, the CV markers IL-6, ET-1, NTproBNP, and leptin were significantly associated with a T level lower than 250 ng/dL.

CLINICAL IMPLICATIONS

Men with low T levels could be at increased risk for increased CV disease as seen by increased CV risk markers.

STRENGTH AND LIMITATIONS

This study was performed in a group of 10,041 men and is the first study to examine CV risk associated with circulating T levels using a large panel of 10 objective biomarkers. This study is limited by an absence of clinical data indicating whether men had pre-existing CV disease or other CV risk factors.

CONCLUSION

Men with low plasma T levels exhibit increases in CV risk markers, consistent with a potential increased risk of CV disease. Pastuszak AW, Kohn TP, Estis J, Lipshultz LI. Low Plasma Testosterone Is Associated With Elevated Cardiovascular Disease Biomarkers. J Sex Med 2017;14:1095-1103.

Troponin I and T in relation to cardiac injury detected with electrocardiography in a population-based cohort - The Maastricht Study

Interest in high-sensitivity cardiac troponin I(hs-cTnI) and T(hs-cTnT) has expanded from acute cardiac care to cardiovascular disease(CVD) risk stratification. Whether hs-cTnI and hs-cTnT are interchangeable in the ambulant setting is largely unexplored. Cardiac injury is a mechanism that may underlie the associations between troponin levels and mortality in the general population. In the population-based Maastricht Study, we assessed the correlation and concordance between hs-cTnI and hs-cTnT. Multiple regression analyses were conducted to assess the association of hs-cTnI and hs-cTnT with electrocardiographic (ECG) changes indicative of cardiac abnormalities. In 3016 eligible individuals(mean age,60 ± 8years;50.6%,men) we found a modest correlation between hs-cTnI and hs-cTnT(r = 0.585). After multiple adjustment, the association with ECG changes indicative of cardiac abnormalities was similar for both hs-cTn assays(OR,hs-cTnI:1.72,95%CI:1.40-2.10;OR,hs-cTnT:1.60,95%CI:1.22–2.11). The concordance of dichotomized hs-cTnI and hs-cTnT was κ = 0.397(≥sex-specific 75^th percentile). Isolated high levels of hs-cTnI were associated with ECG changes indicative of cardiac abnormalities(OR:1.93,95%CI:1.01–3.68), whereas isolated high levels of hs-cTnT were not(OR:1.07,95%CI:0.49–2.31). In conclusion, there is a moderate correlation and limited concordance between hs-cTnI and hs-cTnT under non-acute conditions. These data suggest that associations of hs-cTnI and hs-cTnT with cardiac injury detected by ECG are driven by different mechanisms. This information may benefit future development of CVD risk stratification algorithms.

Equal clinical performance of a novel point-of-care cardiac troponin I (cTnI) assay with a commonly used high-sensitivity cTnI assay

BACKGROUND

Efficient rule-out of acute myocardial infarction (MI) facilitates early disposition of chest pain patients in emergency departments (ED). Point-of-care (POC) cardiac troponin (cTn) may improve patient throughput. We compared the diagnostic accuracy of a novel cTnI test (Minicare cTnI, Philips), with current POC cTnI (I-Stat, Abbott) and high-sensitivity central laboratory cTnI (hs-cTnI; Architect, Abbott) assays.

METHODS

The clinical performance of the assays were compared in samples from 450 patients from a previous clinical evaluation of Minicare cTnI.

RESULTS

Minicare cTnI correlated with Architect hs-cTnI (r²=0.85, p<0.0001) and I-Stat cTnI (r²=0.93, p<0.0001). Areas under the receiver operating characteristics curves were 0.87-0.91 at admission (p=ns) and 0.96-0.97 3h after admission (p=ns). The negative predictive values (NPV) at admission were 95% ((92-97%, 95% CI) for Minicare cTnI and increased to 99% (97-100%) at 2-4h, and similar to Architect hs-cTnI (98%, 96-100%), but higher than I-Stat cTnI (95%, 92-97%; p<0.01). Negative likelihood ratios (LR-) after 2-4h were 0.06 (0.02-0.17, 95% CI) for Minicare cTnI, 0.11 (0.05-0.24) for Architect hs-cTnI (p=0.02) and 0.28 (0.18-0.43) for I-Stat cTnI (p<0.0001). The clinical concordances between Minicare cTnI and Architect hs-cTnI were 92% (admission) and 95% (2-4h), with lower concordances between Minicare cTnI and I-Stat cTnI (83% and 78%, respectively; p=0.007).

CONCLUSIONS

The Minicare cTnI POC assay may become useful for prompt and safe ruling-out of AMI in ED patients with suspected AMI using a guideline supported 0/3h sampling protocol.

Elevated plasma levels of cardiac troponin-I predict left ventricular systolic dysfunction in patients with myotonic dystrophy type 1: A multicentre cohort follow-up study

Objective

High sensitivity plasma cardiac troponin-I (cTnI) is emerging as a strong predictor of cardiac events in a variety of settings. We have explored its utility in patients with myotonic dystrophy type 1 (DM1).

Methods

117 patients with DM1 were recruited from routine outpatient clinics across three health boards. A single measurement of cTnI was made using the ARCHITECT STAT Troponin I assay. Demographic, ECG, echocardiographic and other clinical data were obtained from electronic medical records. Follow up was for a mean of 23 months.

Results

Fifty five females and 62 males (mean age 47.7 years) were included. Complete data were available for ECG in 107, echocardiography in 53. Muscle Impairment Rating Scale score was recorded for all patients. A highly significant excess (p = 0.0007) of DM1 patients presented with cTnI levels greater than the 99^th centile of the range usually observed in the general population (9 patients; 7.6%). Three patients with elevated troponin were found to have left ventricular systolic dysfunction (LVSD), compared with four of those with normal range cTnI (33.3% versus 3.7%; p = 0.001). Sixty two patients had a cTnI level < 5ng/L, of whom only one had documented evidence of LVSD. Elevated cTnI was not predictive of severe conduction abnormalities on ECG, or presence of a cardiac device, nor did cTnI level correlate with muscle strength expressed by Muscle Impairment Rating Scale score.

Conclusions

Plasma cTnI is highly elevated in some ambulatory patients with DM1 and shows promise as a tool to aid cardiac risk stratification, possibly by detecting myocardial involvement. Further studies with larger patient numbers are warranted to assess its utility in this setting.

Prognostic value of basal high-sensitive cardiac troponin levels on mortality in the general population: A meta-analysis

Interest in the use of cardiac troponin T (cTnT) and cardiac troponin I (cTnI) has expanded from diagnosis of acute myocardial infarction to risk assessment for morbidity and mortality. Although cTnT and cTnI were shown to have equivalent diagnostic performance in the setting of suspected acute myocardial infarction, potential prognostic differences are largely unexplored.The aim of this study is to quantify and compare the relationship between cTnT and cTnI, and cardiovascular and all-cause mortality in the general population.Medline, Embase, and the Cochrane Library (from inception through October 2016) were searched for prospective observational cohort studies reporting on the prognostic value of basal high-sensitive cTnT and/or cTnI levels on cardiovascular and all-cause mortality in the general population. Data on study characteristics, participants' characteristics, outcome parameters, and quality [according to the Effective Public Health Practice Project (EPHPP) "Quality Assessment Tool For Quantitative Studies] were retrieved. Hazard ratios per standard deviation increase in basal cardiac troponin level (HR per 1-SD; retrieved from the included articles or estimated) were pooled using a random-effects model.On a total of 2585 reviewed citations, 11 studies, with data on 65,019 participants, were included in the meta-analysis. Random effects pooling showed significant associations between basal cardiac troponin levels and HR for cardiovascular and all-cause mortality [HR per 1-SD 1.29 (95% confidence interval, 95% CI, 1.20-1.38) and HR per 1-SD 1.18 (95% CI, 1.11-1.26), respectively]. Stratified analyses showed higher HRs for cTnT than cTnI [cardiovascular mortality: cTnT HR per 1-SD 1.37 (95% CI, 1.23-1.52); and cTnI HR per 1-SD 1.21 (95% CI, 1.16-1.26); all-cause mortality: cTnT HR per 1-SD 1.31 (955 CI, 1.13-1.53); and cTnI HR per 1-SD 1.14 (95% CI, 1.06-1.22)]. These differences were significant (P < 0.01) in meta-regression analyses for cardiovascular mortality but did not reach statistical significance for all-cause mortality.Elevated, basal cTnT, and cTnI show robust associations with an increased risk of cardiovascular and all-cause mortality during follow-up in the general population.Systematic review registration number PROSPERO CRD42014006964.