High-Sensitivity Cardiac Troponin T (hs-cTnT) as a Predictor of Incident Diabetes in the Atherosclerosis Risk in Communities Study

Association between high sensitivity cardiac troponin and mortality risk in the non-diabetic population: findings from the National Health and Nutrition Examination Survey

OBJECTIVE

We investigated the association of high-sensitivity cardiac troponin (Hs-cTn) with all-cause and cardiovascular mortality in non-diabetic individuals.

METHODS

This study included 10,393 participants without known diabetes and cardiovascular disease from the US National Health and Nutrition Examination Survey (NHANES). Serum Hs-cTnI and Hs-cTnT concentrations were measured. Prediabetes was defined as fasting blood glucose between 100 and 125 mg/dL or HbA1c between 5.7 and 6.4%. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality risk. Time-dependent receiver operating characteristics (tROC) curves were utilized to measure the predictive performance of the biomarkers. Net Reclassification Improvement (NRI) were calculated to estimate the improvement in risk classification for adding Hs-cTnT or Hs-cTnI to the standard models based on Framingham risk factors.

RESULTS

The mean age of the participants was 48.1 ± 19.1 years, with 53.3% being female and 25.8% being prediabetic. After multivariable adjustment, compared to those with Hs-cTnI concentration less than the limit of detection, the HRs (95% CIs) of the participants with Hs-cTnI concentration higher than the 99th upper reference limit were 1.74 (1.35, 2.24) for all-cause mortality and 2.10 (1.36, 3.24) for cardiovascular mortality. The corresponding HRs (95% CIs) for Hs-cTnT were 2.07 (1.53, 2.81) and 2.92 (1.47, 5.80) for all-cause and cardiovascular mortality. There was a significant interaction between prediabetes and Hs-cTnI on the mortality risk; a positive relationship was only observed in prediabetic individuals. No interaction was observed between prediabetes and Hs-cTnT on mortality risk. The Areas Under tROC indicated both Hs-cTnT and Hs-cTnI show better predictive performance in cardiovascular mortality than in all-cause mortality. NRI (95% CI) for adding Hs-cTnT to the standard model were 0.25 (0.21, 0.27) and 0.33 (0.26, 0.39) for all-cause and cardiovascular mortality. The corresponding NRI (95% CI) for Hs-cTnI were 0.04 (0, 0.06) and 0.07 (0.01, 0.13).

CONCLUSIONS

Elevated blood levels of Hs-cTnI and Hs-cTnT are associated with increased mortality. Measurement of Hs-cTnT in non-diabetic subjects, particularly those with prediabetes, may help identify individuals at an increased risk of cardiovascular disease and provide early and more intensive risk factor modification.

Joint effect of highly-sensitive cardiac troponin T and ankle-brachial index on incident cardiovascular events: The MESA and CHS

Background

Elevated highly-sensitive cardiac troponin-T (hs-cTnT≥14 ng/L) and low ankle-brachial index (ABI<0.9) are risk factors for atherosclerotic cardiovascular diseases (ASCVD) but their joint effect on the risk of ASCVD events is unknown.

Methods

We used data from the two population-based cohort studies, the Multi-Ethnic study of Atherosclerosis (MESA) and Cardiovascular Heart Study (CHS) among 10,897 participants free of CVD events at baseline (mean age 66.3 years, 44.7% males). Incident ASCVD was defined as CHD (fatal/non-fatal MI or revascularization), transient ischemic attack, or stroke,. Hazard ratio (HR) and 95% CI was calculated from a Cox regression model. Interaction on the additive scale was assessed using relative excess risk due to interaction (RERI) and interaction on the multiplicative scale was assessed by Likelihood ratio (LR) test.

Results

At baseline (2000-2002 for MESA and 1989-1990 for CHS), 10.2% of participants had elevated hs-cTnT and 7.5% had low ABI. During a median follow-up of 13.6 years (interquartile range, 7.5-14.7 years), there were 2590 incident ASCVD and 1542 incident CHD events. The hazard of CHD and ASCVD was higher in participants with both elevated hs-cTnT and low ABI [HR(95% CI): CHD: 2.04 (1.45, 2.88), ASCVD: 2.05 (1.58, 2.66)] than those with only elevated hs-cTnT [CHD: 1.65 (1.37, 1.99), ASCVD: 1.67 (1.44, 1.99)] or only low ABI [CHD: 1.87 (1.52, 2.31), ASCVD: 1.67 (1.42, 1.97)]. Antagonistic multiplicative interaction was observed for CHD (LR test p-value=0.042) but not for ASCVD (LR test p-value =0.08). No significant additive interaction was detected for CHD and ASCVD (RERI p-value ≥0.23).

Conclusion

The observed joint effect of elevated cTnT and low ABI on ASCVD risk was smaller (i.e., antagonistic interaction) than that expected by the combined independent effects of each risk factor.

Diagnostic and prognostic biomarkers reflective of cardiac remodelling in diabetes mellitus: A scoping review

AIMS

The aim of this scoping review is to evaluate the current biomarkers used in the assessment of adverse cardiac remodelling in people with diabetes mellitus (DM) and in the diagnosis and prognosis of subsequent cardiovascular disease. We aim to discuss the biomarkers' pathophysiological roles as a reflection of the cardiac remodelling mechanisms in the presence of DM.

METHODS

We performed the literature search to include studies from 2003 to 2021 using the following databases: MEDLINE, Scopus, Web of Science, PubMed, and Cochrane library. Articles that met our inclusion criteria were screened and appraised before being included in this review. The PRISMA guidelines for Scoping Reviews were followed.

RESULTS

Our literature search identified a total of 43 eligible articles, which were included in this scoping review. We identified 15 different biomarkers, each described by at least two studies, that were used to determine signs of cardiac remodelling in cardiovascular disease (CVD) and people with DM. NT-proBNP was identified as the most frequently employed biomarker in this context; however, we also identified emerging biomarkers including hs-CRP, hs-cTnT, and Galectin-3.

CONCLUSION

There is a complex relationship between DM and cardiovascular health, where more research is needed. Current biomarkers reflective of adverse cardiac remodelling in DM are often used to diagnose other CVDs, such as NT-proBNP for heart failure. Hence there is a need for identification of specific biomarkers that can detect early signs of cardiac remodelling in the presence of DM. Further research into these biomarkers and mechanisms can deepen our understanding of their role in DM-associated CVD and lead to better preventative therapies.

Cardiac Troponin T in Neonates from Normal and Gestational Diabetes Mellitus Pregnancy

This study is aimed at testing the hypothesis that serum analysis of high-sensitivity troponin T in neonates may serve as a diagnostic tool to predict the risk of gestational diabetes mellitus (GDM). 86 newborns were studied and stratified into two groups: healthy group; newborns with body weight ≥ 10th percentile, born in good condition (APG 8-10pts) of pregnancy not complicated by diabetes, and the GDM group; neonates born to mothers with type 1 or type 2 diabetes. Results. The study revealed minimal troponin levels in GDM, and healthy groups equal to 0.02 ng/mL and 0.028 ng/mL, respectively. The GDM group is defined by an interquartile range of hs-TnT higher than the healthy group. This study confirms previously reported upper levels of troponin in healthy children. There are possible health problems that can appear during infancy and influence the further development of a child affected by GDM.

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.

The Africans in America study demonstrates that subclinical cardiovascular risk differs by etiology of abnormal glucose tolerance

Abnormal-glucose tolerance (Abnl-GT) is due to an imbalance between β-cell function and insulin resistance (IR) and is a major risk factor in cardiovascular disease (CVD). In sub-Saharan Africa, β-cell failure is emerging as an important cause of Abnl-GT (Abnl-GT-β-cell-failure). Visceral adipose tissue (VAT) volume and hyperlipidemia are major contributors to CVD risk when Abnl-GT is due to IR (Abnl-GT-IR). Yet, the CVD profile associated with Abnl-GT-β-cell failure is unknown. Therefore, our goals in 450 African-born Blacks (Male: 65%; Age: 39 ± 10 years; BMI 28 ± 5 kg/m²), living in America were to: (1) determine Abnl-GT prevalence and etiology; (2) assess by Abnl-GT etiology, associations between four understudied subclinical CVD risk factors in Africans: (a) subclinical myocardial damage (high-sensitivity troponin T (hs-cTnT)); (b) neurohormonal regulation (N-terminal pro-Brain-natriuretic peptide (NT-proBNP)); (c) coagulability (fibrinogen); (d) inflammation (high-sensitivity C-reactive protein (hsCRP)), as well as HbA_1c, Cholesterol/HDL ratio and VAT. Glucose tolerance status was determined by the OGTT. IR was defined by the threshold at the lowest quartile for the Matsuda Index (≤ 2.97). Abnl-GT-IR required both Abnl-GT and IR. Abnl-GT-β-cell-failure was defined as Abnl-GT without IR. VAT was assessed by CT-scan. For both the Abnl-GT-β-cell-failure and Abnl-GT-IR groups, four multiple regression models were performed for hs-cTnT; NT-proBNP; fibrinogen and hsCRP, as dependent variables, with the remaining three biomarkers and HbA_1c, Cholesterol/HDL and VAT as independent variables. Abnl-GT occurred in 38% (170/450). In the Abnl-GT group, β-cell failure occurred in 58% (98/170) and IR in 42% (72/170). VAT and Cholesterol/HDL were significantly lower in Abnl-GT-β-cell-failure group vs the Abnl-GT-IR group (both P < 0.001). In the Abnl-GT-β-cell-failure group: significant associations existed between hscTnT, fibrinogen, hs-CRP, and HbA_1c (all P < 0.05), and none with Cholesterol/HDL or VAT. In Abnl-GT-IR: hs-cTnT, fibrinogen and hsCRP significantly associated with Cholesterol/HDL (all P < 0.05) and NT-proBNP inversely related to fibrinogen, hsCRP, HbA_1c, Cholesterol/HDL, and VAT (all P < 0.05). The subclinical CVD risk profile differed between Abnl-GT-β-cell failure and Abnl-GT-IR. In Abnl-GT-β-cell failure subclinical CVD risk involved subclinical-myocardial damage, hypercoagulability and increased inflammation, but not hyperlipidemia or visceral adiposity. For Abnl-GT-IR, subclinical CVD risk related to subclinical myocardial damage, neurohormonal dysregulation, inflammation associated with hyperlipidemia and visceral adiposity. ClinicalTrials.gov Identifier: NCT00001853.

Cardiovascular biomarkers in pregnancy with diabetes and associations to glucose control

AIM

Cardiovascular disease (CVD) is a leading cause of death in both men and women. Type 1 and 2 diabetes mellitus (DM1 and DM2) are well-known risk factors for CVD. In addition, gestational diabetes mellitus (GDM) is a female sex-specific risk factor for CVD. Here, we measure circulating concentrations of cardiac troponin T (cTNT), N-terminal pro-B-type natriuretic peptide (NT-proBNP) and growth differentiation factor 15 (GDF-15) during pregnancy-a window of time often referred to as a cardiovascular stress test for women.

METHODS

This study utilized data from 384 pregnant women: 64 with DM1, 16 with DM2, 35 with GDM and 269 euglycemic controls. Blood was predominantly sampled within a week before delivery. Cardiovascular biomarker concentrations were measured in serum using electrochemiluminescence immunoassay.

RESULT

Circulating cTnT levels were higher in women with DM1, DM2 and GDM as compared to controls, whereas NT-proBNP and GDF-15 levels were only increased in women with DM1. Glucose dysregulation, assessed by third trimester HbA1c levels, positively correlated with all three CVD biomarker levels, whereas pregestational body mass index correlated negatively with GDF-15.

CONCLUSIONS

Our results support the presence of myocardial affection in women with diabetic disorders during pregnancy. Although pregestational DM1 in this study was associated with the most adverse CVD biomarker profile, women with GDM displayed an adverse cTnT profile similar to what we found in women with pregestational DM2. This supports that women with GDM should be offered long-term intensified cardiovascular follow-up and lifestyle advice following delivery, similarly to the well-established CV follow-up of women with pregestational DM.

Multi-dimensional characterization of prediabetes in the Project Baseline Health Study

Background

We examined multi-dimensional clinical and laboratory data in participants with normoglycemia, prediabetes, and diabetes to identify characteristics of prediabetes and predictors of progression from prediabetes to diabetes or reversion to no diabetes.

Methods

The Project Baseline Health Study (PBHS) is a multi-site prospective cohort study of 2502 adults that conducted deep clinical phenotyping through imaging, laboratory tests, clinical assessments, medical history, personal devices, and surveys. Participants were classified by diabetes status (diabetes [DM], prediabetes [preDM], or no diabetes [noDM]) at each visit based on glucose, HbA1c, medications, and self-report. Principal component analysis (PCA) was performed to create factors that were compared across groups cross-sectionally using linear models. Logistic regression was used to identify factors associated with progression from preDM to DM and for reversion from preDM to noDM.

Results

At enrollment, 1605 participants had noDM; 544 had preDM; and 352 had DM. Over 4 years of follow-up, 52 participants with preDM developed DM and 153 participants reverted to noDM. PCA identified 33 factors composed of clusters of clinical variables; these were tested along with eight individual variables identified a priori as being of interest. Six PCA factors and six a priori variables significantly differed between noDM and both preDM and DM after false discovery rate adjustment for multiple comparisons (q < 0.05). Of these, two factors (one comprising glucose measures and one of anthropometry and physical function) demonstrated monotonic/graded relationships across the groups, as did three a priori variables: ASCVD risk, coronary artery calcium, and triglycerides (q < 10^–21 for all). Four factors were significantly different between preDM and noDM, but concordant or similar between DM and preDM: red blood cell indices (q = 8 × 10^-10), lung function (q = 2 × 10^-6), risks of chronic diseases (q = 7 × 10^-4), and cardiac function (q = 0.001), along with a priori variables of diastolic function (q = 1 × 10^-10), sleep efficiency (q = 9 × 10^-6) and sleep time (q = 6 × 10^-5). Two factors were associated with progression from prediabetes to DM: anthropometry and physical function (OR [95% CI]: 0.6 [0.5, 0.9], q = 0.04), and heart failure and c-reactive protein (OR [95% CI]: 1.4 [1.1, 1.7], q = 0.02). The anthropometry and physical function factor was also associated with reversion from prediabetes to noDM: (OR [95% CI]: 1.9 [1.4, 2.7], q = 0.02) along with a factor of white blood cell indices (OR [95% CI]: 0.6 [0.4, 0.8], q = 0.02), and the a priori variables ASCVD risk score (OR [95% CI]: 0.7 [0.6, 0.9] for each 0.1 increase in ASCVD score, q = 0.02) and triglycerides (OR [95% CI]: 0.9 [0.8, 1.0] for each 25 mg/dl increase, q = 0.05).

Conclusions

PBHS participants with preDM demonstrated pathophysiologic changes in cardiac, pulmonary, and hematology measures and declines in physical function and sleep measures that precede DM; some changes predicted an increased risk of progression to DM. A factor with measures of anthropometry and physical function was the most important factor associated with progression to DM and reversion to noDM. Future studies may determine whether these changes elucidate pathways of progression to DM and related complications and whether they can be used to identify individuals at higher risk of progression to DM for targeted preventive interventions.

Trial registration ClinicalTrials.gov NCT03154346

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01565-x.

Serum Troponin T Concentrations Are Frequently Elevated in Advanced Skin Cancer Patients Prior to Immune Checkpoint Inhibitor Therapy: Experience From a Single Tertiary Referral Center

Immune checkpoint inhibitor (ICI) therapy has revolutionized the treatment of several human malignancies, particularly metastatic skin cancer. However, immune-related myocarditis (irM), an immune-mediated adverse event (irAE), is often fatal. In the absence of a reliable biomarker, measurement of pre-ICI therapy serum troponin concentration has been proposed to identify patients at risk of developing irM, although real-world studies examining this strategy are lacking. Thus, we retrospectively analyzed the case records of all patients who commenced ICI therapy between January 2018 and December 2019 in a single university skin cancer center (n = 121) to (i) determine the incidence of irM, (ii) establish the frequency of pretreatment serum hsTnT elevations, and (iii) to establish whether this identified patients who subsequently developed irM. Only one patient developed irM, resulting in an overall incidence of 0.8%. Pretreatment hsTnT was measured in 47 patients and was elevated in 13 (28%). Elevated serum hsTnT concentrations were associated with chronic renal failure (p = 0.02) and diabetes (p < 0.0002). Pretreatment hsTnT was not elevated in the patient who developed fulminant irM. Pre-immunotherapy serum hsTnT concentrations were often asymptomatically elevated in patients with advanced skin cancer, none of whom subsequently developed irM during ICI therapy. However, large studies are required to assess the positive and negative predictive values of hsTnT for the development of irM. In the meantime, elevated hsTnT concentrations should be investigated before initiation of immunotherapy and closely monitored during early treatment cycles, where the risk of irM is greatest.

High Burden of Subclinical and Cardiovascular Disease Risk in Adults With Metabolically Healthy Obesity: The Atherosclerosis Risk in Communities (ARIC) Study

OBJECTIVE

It is controversial whether adults who are obese but "metabolically healthy" have cardiovascular disease (CVD) risk comparable with that of normal-weight adults. High-sensitivity cardiac troponin T (hs-cTnT), a biomarker of myocardial damage, is useful in characterizing subclinical CVD. We categorized obesity phenotypes and studied their associations with subclinical and clinical CVD and CVD subtypes, including heart failure (HF).

RESEARCH DESIGN AND METHODS

We conducted cross-sectional and prospective analyses of 9,477 adults in the Atherosclerosis Risk in Communities (ARIC) study. We used the Adult Treatment Panel III criteria and BMI to define obesity phenotypes as follows: metabolically healthy normal weight, metabolically healthy overweight, metabolically healthy obese, metabolically unhealthy normal weight, metabolically unhealthy overweight, and metabolically unhealthy obese.

RESULTS

At baseline (1990-1992), mean age was 56 years, 56% were female, 23% were Black, and 25% had detectable hs-cTnT (≥6 ng/L). Over a median of 17 years of follow-up, there were 2,603 clinical CVD events. Those with the metabolically healthy obese (hazard ratio [HR] 1.38, 95% CI 1.15-1.67), metabolically unhealthy normal weight (HR 1.51, 95% CI 1.30-1.76), metabolically unhealthy overweight (HR 1.60, 95% CI 1.41-1.82), and metabolically unhealthy obese (HR 2.14, 95% CI 1.88-2.44) phenotypes had higher CVD risks in comparison with metabolically healthy normal weight. Detectable hs-cTnT (≥6 ng/L) was associated with higher CVD risk, even among metabolically healthy normal-weight adults. Metabolically healthy obese adults had higher HF risk (HR 1.65, 95% CI 1.30-2.09) in comparison with metabolically healthy normal weight.

CONCLUSIONS

The metabolically healthy obese phenotype was associated with excess burden of clinical CVD, primarily driven by an excess risk of HF. hs-cTnT was useful in stratifying CVD risk across all obesity phenotypes, even among obese individuals who appear otherwise metabolically healthy.

Phenotyping the Prediabetic Population-A Closer Look at Intermediate Glucose Status and Cardiovascular Disease

Even though the new thresholds for defining prediabetes have been around for more than ten years, there is still controversy surrounding the precise characterization of this intermediate glucose metabolism status. The risk of developing diabetes and macro and microvascular disease linked to prediabetes is well known. Still, the prediabetic population is far from being homogenous, and phenotyping it into less heterogeneous groups might prove useful for long-term risk assessment, follow-up, and primary prevention. Unfortunately, the current definition of prediabetes is quite rigid and disregards the underlying pathophysiologic mechanisms and their potential metabolic progression towards overt disease. In addition, prediabetes is commonly associated with a cluster of risk factors that worsen the prognosis. These risk factors all revolve around a common denominator: inflammation. This review focuses on identifying the population that needs to be screened for prediabetes and the already declared prediabetic patients who are at a higher risk of cardiovascular disease and require closer monitoring.

Prognostic performance of troponin in COVID-19: A diagnostic meta-analysis and meta-regression

BACKGROUND

Cardiac injury is frequently encountered in patients with coronavirus disease 2019 (COVID-19) and is associated with increased risk of mortality. Elevated troponin may signify myocardial damage and is predictive of mortality. This study aimed to assess the prognostic value of troponin above the 99th percentile upper reference limit (URL) for mortality, and factors affecting the relationship.

METHODS

A comprehensive literature search of PubMed (MEDLINE), Scopus and Embase was undertaken, from inception of the databases until 16 December 2020. The key exposure was elevated serum troponin, defined as troponin (of any type) above the 99th percentile URL. The outcome was mortality due to any cause.

RESULTS

In total, 12,262 patients from 13 studies were included in this systematic review and meta-analysis. The mortality rate was 23% (20-26%). Elevated troponin was observed in 31% (23-38%) of patients. Elevated troponin was associated with increased mortality [odds ratio (OR) 4.75, 95% confidence interval (CI) 4.07-5.53; P < 0.001; I² = 19.9%]. Meta-regression showed that the association did not vary with age (P = 0.218), male gender (P = 0.707), hypertension (P = 0.182), diabetes (P = 0.906) or coronary artery disease (P = 0864). The association between elevated troponin and mortality had sensitivity of 0.55 (0.44-0.66), specificity of 0.80 (0.71-0.86), positive likelihood ratio of 2.7 (2.2-3.3), negative likelihood ratio of 0.56 (0.49-0.65), diagnosis odds ratio of 5 (4-5) and area under the curve of 0.73 (0.69-0.77). The probability of mortality was 45% in patients with elevated troponin and 14% in patients with non-elevated troponin.

CONCLUSION

Elevated troponin was associated with mortality in patients with COVID-19 with 55% sensitivity and 80% specificity.

A Test in Context: Interpretation of High-Sensitivity Cardiac Troponin Assays in Different Clinical Settings

High-sensitivity cardiac troponin (hs-cTn) assays have the ability to detect minute troponin concentrations and resolve minor changes in biomarker concentrations. Clinically, this allows for the ability to rapidly identify or exclude acute myocardial injury in the setting of acute chest discomfort-thus providing more rapid evaluation for acute myocardial infarction-but the improvements in troponin assays also create avenues for other applications where troponin release from the cardiomyocyte might confer prognostic information. These situations include cardiovascular risk assessment across a wide range of clinical circumstances, including apparently-well individuals, those at risk for heart disease, and those with prevalent cardiovascular disorders. The optimal hs-cTn threshold for each circumstance varies by the assay used and by the population assessed. This review will provide context for how hs-cTn assays might be interpreted depending on the application sought, reviewing results from studies leveraging hs-cTn for applications beyond "acute myocardial infarction diagnostic evaluation."

Associations of Cardiac, Kidney, and Diabetes Biomarkers With Peripheral Neuropathy among Older Adults in the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

The aim of this study was to assess the association of high-sensitivity cardiac troponin (hs-cTnT) and other cardiac, kidney, hyperglycemia, and inflammatory biomarkers with peripheral neuropathy (PN) in a community-based population.

METHODS

We conducted a cross-sectional analysis of 3056 black and white participants in the Atherosclerosis Risk in Communities (ARIC) study who underwent standardized monofilament PN testing and had measures of cardiac function (hs-cTnT, N-terminal pro-B-type natriuretic peptide [NT-proBNP], and growth differentiation factor 15 [GDF15]), kidney function (serum creatinine, cystatin C, β-2 microglobulin, urine albumin-to-creatinine ratio), hyperglycemia (fasting glucose, hemoglobin A1c [Hb A1c], fructosamine, glycated albumin, 1,5-anhydroglucitol), and inflammation (C-reactive protein) assessed at visit 6 (2016-2017; age 71-94 years). We used logistic regression to assess the associations of these biomarkers (modeled in diabetes-specific tertiles) with PN in older adults with and without diabetes after adjusting for traditional risk factors.

RESULTS

In total, 33.5% of participants had PN (37.3% with diabetes and 31.9% without diabetes). There was an independent association of hs-cTnT with PN regardless of diabetes status (diabetes T3 vs. T1: odds ratio [OR], 2.15 [95% CI, 1.44-3.22]; no diabetes: OR, 2.31 [95%CI, 1.76-3.03]; P = 0.72 for interaction). Among participants without diabetes, there were also significant associations of NT-proBNP (OR, 1.40 [95% CI, 1.08-1.81]) and urine albumin-to-creatinine ratio (OR, 1.55 [95% CI, 1.22-1.97]) with PN. Associations of hyperglycemia biomarkers including Hb A1c (OR, 1.76 [95% CI, 1.22-2.54]), fructosamine (OR, 1.71 [95% CI, 1.19-2.46]), and glycated albumin (OR, 1.45 [95% CI, 1.03-2.03]) with PN were significant only among participants with diabetes.

CONCLUSIONS

Overall, hs-cTnT appears to be a global marker of end organ damage, including PN. Laboratory biomarkers may be able to help us identify those individuals with PN.

Benefits of Home-Based Solutions for Diagnosis and Treatment of Acute Coronary Syndromes on Health Care Costs: A Systematic Review

Diagnosing and treating acute coronary syndromes consumes a significant fraction of the healthcare budget worldwide. The pressure on resources is expected to increase with the continuing rise of cardiovascular disease, other chronic diseases and extended life expectancy, while expenditure is constrained. The objective of this review is to assess if home-based solutions for measuring chemical cardiac biomarkers can mitigate or reduce the continued rise in the costs of ACS treatment. A systematic review was performed considering published literature in several relevant public databases (i.e., PUBMED, Cochrane, Embase and Scopus) focusing on current biomarker practices in high-risk patients, their cost-effectiveness and the clinical evidence and feasibility of implementation. Out of 26,000 references screened, 86 met the inclusion criteria after independent full-text review. Current clinical evidence highlights that home-based solutions implemented in primary and secondary prevention reduce health care costs by earlier diagnosis, improved patient outcomes and quality of life, as well as by avoidance of unnecessary use of resources. Economical evidence suggests their potential to reduce health care costs if the incremental cost-effectiveness ratio or the willingness-to-pay does not surpass £20,000/QALY or €50,000 limit per 20,000 patients, respectively. The cost-effectiveness of these solutions increases when applied to high-risk patients.

Performance of the ESC 0/1-h and 0/3-h Algorithm for the Rapid Identification of Myocardial Infarction Without ST-Elevation in Patients With Diabetes

OBJECTIVE

Patients with diabetes mellitus (DM) have elevated levels of high-sensitivity cardiac troponin (hs-cTn). We investigated the diagnostic performance of the European Society of Cardiology (ESC) algorithms to rule out or rule in acute myocardial infarction (AMI) without ST-elevation in patients with DM.

RESEARCH DESIGN AND METHODS

We prospectively enrolled 3,681 patients with suspected AMI and stratified those by the presence of DM. The ESC 0/1-h and 0/3-h algorithms were used to calculate negative and positive predictive values (NPV, PPV). In addition, alternative cutoffs were calculated and externally validated in 2,895 patients.

RESULTS

In total, 563 patients (15.3%) had DM, and 137 (24.3%) of these had AMI. When the ESC 0/1-h algorithm was used, the NPV was comparable in patients with and without DM (absolute difference [AD] -1.50 [95% CI -5.95, 2.96]). In contrast, the ESC 0/3-h algorithm resulted in a significantly lower NPV in patients with DM (AD -2.27 [95% CI -4.47, -0.07]). The diagnostic performance for rule-in of AMI (PPV) was comparable in both groups: 0/1-h (AD 6.59 [95% CI -19.53, 6.35]) and 0/3-h (AD 1.03 [95% CI -7.63, 9.7]). Alternative cutoffs increased the PPV in both algorithms significantly, while improvements in NPV were only subtle.

CONCLUSIONS

Application of the ESC 0/1-h algorithm revealed comparable safety to rule out AMI comparing patients with and without DM, while this was not observed with the ESC 0/3-h algorithm. Although alternative cutoffs might be helpful, patients with DM remain a high-risk population in whom identification of AMI is challenging and who require careful clinical evaluation.

Relationship between hemoglobin A1c and serum troponin in patients with diabetes and cardiovascular events

OBJECTIVES

Diabetes mellitus is a group of metabolic disorders associated with high risk for cardiovascular disease. Although troponins are primarily clinically used for the diagnosis of acute coronary syndrome, they are also used in risk assessment in patients with acute coronary syndrome as well as in a number of other conditions. The aim of this review was to investigate the relationship between hemoglobin A1c and serum troponin in patients with diabetes and cardiovascular events.

METHODS

Hemoglobin A1c has been chosen as the best clinical indicator of glucose control and risk of micro and macrovascular complications. We investigated cardiac troponins as a group of markers of muscle injury which includes troponin T, troponin I and troponin C. Troponin T and I are specific for myocardial injury, compared to C which is specific for skeletal muscle.

RESULTS

In this review, we showed that there was a causal relation between hemoglobin A1c levels and serum troponin concentrations. Hemoglobin A1c has shown to be a positive predictive factor of incidence, mortality and morbidity of conditions such as acute coronary syndrome, arrhythmias, stroke, pulmonary embolism and other conditions that causes troponin elevation by its release in circulation.

CONCLUSIONS

Chronic hyperglycemia decreases glomerular filtration and consequently decreases troponin elimination and also by affecting the heart microcirculation it leads to microvascular damage and consequently to ischemia which contribute to troponin concentration elevation. Furthermore, correlation between hemoglobin A1c and troponin concentration manifests in their prognostic value for mortality.

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.

Development of type 2 diabetes mellitus in people with intermediate hyperglycaemia

BACKGROUND

Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycosylated haemoglobin A1c (HbA1c). These levels are higher than normal but below the diagnostic threshold for type 2 diabetes mellitus (T2DM). The reduced threshold of 5.6 mmol/L (100 mg/dL) fasting plasma glucose (FPG) for defining IFG, introduced by the American Diabetes Association (ADA) in 2003, substantially increased the prevalence of IFG. Likewise, the lowering of the HbA1c threshold from 6.0% to 5.7% by the ADA in 2010 could potentially have significant medical, public health and socioeconomic impacts.

OBJECTIVES

To assess the overall prognosis of people with IH for developing T2DM, regression from IH to normoglycaemia and the difference in T2DM incidence in people with IH versus people with normoglycaemia.

SEARCH METHODS

We searched MEDLINE, Embase, ClincialTrials.gov and the International Clinical Trials Registry Platform (ICTRP) Search Portal up to December 2016 and updated the MEDLINE search in February 2018. We used several complementary search methods in addition to a Boolean search based on analytical text mining.

SELECTION CRITERIA

We included prospective cohort studies investigating the development of T2DM in people with IH. We used standard definitions of IH as described by the ADA or World Health Organization (WHO). We excluded intervention trials and studies on cohorts with additional comorbidities at baseline, studies with missing data on the transition from IH to T2DM, and studies where T2DM incidence was evaluated by documents or self-report only.

DATA COLLECTION AND ANALYSIS

One review author extracted study characteristics, and a second author checked the extracted data. We used a tailored version of the Quality In Prognosis Studies (QUIPS) tool for assessing risk of bias. We pooled incidence and incidence rate ratios (IRR) using a random-effects model to account for between-study heterogeneity. To meta-analyse incidence data, we used a method for pooling proportions. For hazard ratios (HR) and odds ratios (OR) of IH versus normoglycaemia, reported with 95% confidence intervals (CI), we obtained standard errors from these CIs and performed random-effects meta-analyses using the generic inverse-variance method. We used multivariable HRs and the model with the greatest number of covariates. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.

MAIN RESULTS

We included 103 prospective cohort studies. The studies mainly defined IH by IFG5.6 (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG6.1 (FPG 6.1 mmol/L to 6.9 mmol/L or 110 mg/dL to 125 mg/dL), IGT (plasma glucose 7.8 mmol/L to 11.1 mmol/L or 140 mg/dL to 199 mg/dL two hours after a 75 g glucose load on the oral glucose tolerance test, combined IFG and IGT (IFG/IGT), and elevated HbA1c (HbA1c5.7: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c6.0: HbA1c 6.0% to 6.4% or 42 mmol/mol to 46 mmol/mol). The follow-up period ranged from 1 to 24 years. Ninety-three studies evaluated the overall prognosis of people with IH measured by cumulative T2DM incidence, and 52 studies evaluated glycaemic status as a prognostic factor for T2DM by comparing a cohort with IH to a cohort with normoglycaemia. Participants were of Australian, European or North American origin in 41 studies; Latin American in 7; Asian or Middle Eastern in 50; and Islanders or American Indians in 5. Six studies included children and/or adolescents.Cumulative incidence of T2DM associated with IFG5.6, IFG6.1, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG6.1 and IFG5.6. Limited data showed a higher T2DM incidence associated with HbA1c6.0 compared to HbA1c5.7. We rated the evidence for overall prognosis as of moderate certainty because of imprecision (wide CIs in most studies). In the 47 studies reporting restitution of normoglycaemia, regression ranged from 33% to 59% within one to five years follow-up, and from 17% to 42% for 6 to 11 years of follow-up (moderate-certainty evidence).Studies evaluating the prognostic effect of IH versus normoglycaemia reported different effect measures (HRs, IRRs and ORs). Overall, the effect measures all indicated an elevated risk of T2DM at 1 to 24 years of follow-up. Taking into account the long-term follow-up of cohort studies, estimation of HRs for time-dependent events like T2DM incidence appeared most reliable. The pooled HR and the number of studies and participants for different IH definitions as compared to normoglycaemia were: IFG5.6: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG6.1: HR 5.47 (95% CI 3.50 to 8.54), 9 studies, 2818 participants; IGT: HR 3.61 (95% CI 2.31 to 5.64), 5 studies, 4010 participants; IFG and IGT: HR 6.90 (95% CI 4.15 to 11.45), 5 studies, 1038 participants; HbA1c5.7: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c6.0: HR 10.10 (95% CI 3.59 to 28.43), 6 studies, 4532 participants. In subgroup analyses, there was no clear pattern of differences between geographic regions. We downgraded the evidence for the prognostic effect of IH versus normoglycaemia to low-certainty evidence due to study limitations because many studies did not adequately adjust for confounders. Imprecision and inconsistency required further downgrading due to wide 95% CIs and wide 95% prediction intervals (sometimes ranging from negative to positive prognostic factor to outcome associations), respectively.This evidence is up to date as of 26 February 2018.

AUTHORS' CONCLUSIONS

Overall prognosis of people with IH worsened over time. T2DM cumulative incidence generally increased over the course of follow-up but varied with IH definition. Regression from IH to normoglycaemia decreased over time but was observed even after 11 years of follow-up. The risk of developing T2DM when comparing IH with normoglycaemia at baseline varied by IH definition. Taking into consideration the uncertainty of the available evidence, as well as the fluctuating stages of normoglycaemia, IH and T2DM, which may transition from one stage to another in both directions even after years of follow-up, practitioners should be careful about the potential implications of any active intervention for people 'diagnosed' with IH.

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.

Sensitive detection of cardiac troponin T based on superparamagnetic bead-labels using a flexible micro-fluxgate sensor

In this study, we describe an innovative micro-fluxgate immunosensor based on superparamagnetic Dynabeads for the detection of cardiac troponin T (cTnT), an important biomarker for cardiovascular diseases.