Prognostic value of cardiac troponin I measured with a highly sensitive assay in patients with stable coronary artery disease

Biomarkers in coronary artery disease: systematic review and meta-analysis

INTRODUCTION

Little information exists regarding the detection of early coronary heart disease protein biomarkers. The aim of this study was to investigate several potential candidates.

METHODS

Systematic review was carried out followed by meta-analysis.

RESULTS

The standardized mean difference (95% confidence intervals) for each comparison was: Troponins 2.31 (1.18, 3.4), iL-6 1.3 (0.8, 1.81), fibrinogen 1.55 (1.16, 1.94), NT-proBNP 1.05 (0.72, 1.38), lipoprotein a 0.75 (0.48, 1.03) osteoprotegerin 0.92 (0.23, 1.62), VCAM-1 1.53 (0.87, 2.18), pentraxin 3 0.87 (-0.13, 1.87), PAI-1 2.51 (-0.65, 5.66) MMP9 1.25 (0.36, 2.14), MCP-1 1.99 (1.12, 2.85) and adiponectin -1.11 (-1.49, -0.73).

CONCLUSION

Multiple biomarkers that could potentially be used for the early detection of coronary heart disease were identified.

Cardiac biomarkers and CT coronary angiography for the assessment of coronary heart disease

Over the last 30 years, the widespread use of cardiac biomarkers has transformed the diagnostic evaluation of patients with coronary heart disease. Cardiac troponin is integral to the definition of acute myocardial infarction. High-sensitivity cardiac troponin (hs-cTn) assays can improve risk stratification to facilitate both the rapid rule out of myocardial infarction and prediction of future cardiovascular events. Numerous circulating biomarkers representing different pathological pathways improve prediction of atherosclerotic cardiovascular disease (ACVD) and coronary artery disease (CAD). In parallel, coronary computed tomography angiography (CCTA) has become the most widely used imaging modality for the evaluation of patients with possible angina. CCTA now allows for the quantification of coronary calcification, atherosclerotic plaque volume and different plaque characteristics, enabling the identification high-risk features and inflammation. In the future, the use of CCTA is likely to extend to risk stratification for the prevention of ACVD. As such, how to integrate these diagnostic and prognostic circulating and imaging biomarkers is a topic of considerable interest. This review aims to describe current status and future possibilities for the integration of CCTA and cardiac biomarker testing to improve the identification and treatment of individuals with coronary heart disease and heightened cardiovascular risk.

Associations of elevated cardiac biomarkers with hyperuricemia and mortality in US adults without prevalent cardiovascular disease

Background

NT-proBNP (N-terminal pro-B-type natriuretic peptide), high-sensitivity cardiac troponin T (hs-troponin T), and high-sensitivity cardiac troponin I (hs-troponin I) have been widely recognized as significant cardiac biomarkers, and are increasingly being recommended for early risk identification in cardiovascular high-risk populations. The aim of our study was to evaluate the prevalence of elevated cardiac biomarkers (NT-proBNP, hs-troponin T, hs-troponin I) and their association with the risk of hyperuricemia in the general US adults without known cardiovascular disease. We further studied whether elevated cardiac biomarkers are associated with an increased risk of all-cause and cardiovascular mortality in individuals with or without hyperuricemia.

Methods

The study population came from the adults (age ≥20y) without prevalent cardiovascular disease in NHANES (National Health and Nutrition Examination Survey) 1999 to 2004. We evaluated the prevalence of elevated cardiac biomarkers among adults with or without hyperuricemia, and conducted a comprehensive multivariate logistic regression analysis to ascertain the association between elevated cardiac biomarkers and hyperuricemia risk. Multivariate Cox regression model and Kaplan-Meier curve, risk competition model and Cumulative Incidence Function(CIF) were used respectively to examine the associations between elevated cardiac biomarkers with all-cause and cardiovascular mortality.

Results

In general US adults without known cardiovascular disease, the prevalence of hyperuricemia was 16.35%. The age-adjustd prevalence of elevated NT-proBNP (≥125 pg/mL), hs-troponin T (≥6 ng/L), and hs-troponin I (male ≥6, female ≥4 ng/L) was 16.70%, 49.80%, and 11.91%, respectively, among adults with hyperuricemia. Adjusted multivariable logistic regression analysis revealed a statistically significant association between elevated levels of NT-proBNP, hs-troponin T, and hs-troponin I and hyperuricemia, and different clinical categories observed grade differences on the same cardiac biomarker. Elevated NT-proBNP, hs-troponinT and hs-troponinI were each significantly positively associated with the cumulative incidence of all-cause and cardiovascular mortality in adults with or without hyperuricemia. Compared to those with elevated cardiac biomarkers only, adults with hyperuricemia and elevated cardiac biomarkers faced the highest risk of all-cause and cardiovascular mortality.

Conclusions

Our study identified that elevated cardiac biomarkers pose a high burden on hyperuricemia risk in the general population without known cardiovascular disease, and further provides important information on long-term mortality risk in these populations. Routine testing of cardiac biomarkers may be useful for early risk identification and prognostic assessment in adults with hyperuricemia.

NT-proBNP and Cardiac Troponin I, but Not Cardiac Troponin T, Are Associated With 7-Year Changes in Cardiac Structure and Function in Older Adults: The ARIC Study

BACKGROUND

Higher circulating concentrations of NT-proBNP (N-terminal pro-B-type natriuretic peptide) and high-sensitivity cardiac troponin T (hs-cTnT) and I (hs-cTnI) are associated with left ventricular remodeling and with incident heart failure. The associations of these cardiac biomarkers with changes in cardiac structure and function over time are uncharacterized.

METHODS

Among 2006 participants in the ARIC prospective cohort study (Atherosclerosis Risk in Communities) who were free of overt cardiovascular disease and underwent echocardiography at study visits 5 (2011- 2013) and 7 (2018-2019), we assessed the associations of NT-proBNP, hs-cTnT, and hs-cTnI concentrations at visit 5 with changes in left ventricular structure and function between visits 5 and 7 (≈7-year change) using multivariable linear regression with the biomarkers modeled as restricted cubic splines. Models were adjusted for age, sex, race, body mass index, smoking, diabetes, hypertension, and renal function at visit 5; blood pressure and heart rate at both visits; and the baseline value of the echocardiographic parameter of interest.

RESULTS

Mean±SD age was 74±4 years at visit 5; 61% were women; and 23% were Black adults. Median (25th-75th percentile) concentrations at visit 5 of NT-proBNP, hs-cTnT, and hs-cTnI were 87 ng/L (50-157 ng/L), 9 ng/L (6-12 ng/L), and 2.6 ng/L (1.9-3.9 ng/L). In adjusted models, elevated baseline concentrations of NT-proBNP and hs-cTnI were significantly associated with 7-year decline in left ventricular systolic function (ejection fraction, longitudinal and circumferential strain) and worsening diastolic indices. In contrast, elevated baseline concentrations of hs-cTnT were not significantly associated with 7-year changes in cardiac structure, systolic function, or diastolic function (all P>0.05).

CONCLUSIONS

Higher concentrations of NT-proBNP and hs-cTnI, but not hs-cTnT, were associated with greater declines in left ventricular function over ≈7 years in late life independently of traditional cardiovascular risk factors.

A systematic review and meta-analysis evaluating the association of high sensitivity troponin levels with outcomes in patients with stable coronary artery disease

BACKGROUND

High-sensitivity cardiac troponins (Hs-cTns) are reliable indicators of myocardial injury, but their relationship with cardiovascular outcomes remains less understood. This study explores the association between adverse cardiac events and Hs-cTnT levels exceeding 14 ng/L in patients with stable CAD.

METHODS

Thirteen pertinent studies were identified using specific keywords from a pool of 208 articles retrieved from PubMed, Scopus, and Google Scholar, spanning 2013 to 2023. The primary outcomes included all-cause mortality (ACM), myocardial infarction (MI), cardiovascular death (CVD), rehospitalization due to decompensated heart failure (RDHF), need for revascularization, and stroke. Comprehensive meta-analysis (CMA) was employed to analyze the data for odds ratios (OR) and 95% confidence intervals (CI). Heterogeneity was assessed using I2 statistics, and both qualitative assessment (Newcastle-Ottawa Scale) and quantitative analysis (Egger's and Beggs test, funnel plots) were conducted.

RESULTS

The analysis included 29,115 participants (74.72% male) with a mean age of 68.34 years. It revealed a significantly elevated risk of ACM among stable CAD patients with Hs-cTnT levels >14 ng/L compared to those with levels <14 ng/L (11.2% vs. 3.3%; OR = 5.46; 95% CI = 1.53-19.54; p = 0.009). Similarly, higher risks were observed for MI (10.9% vs 3.6%; OR = 3.12; 95% CI = 0.98-9.95, p = 0.053), CVD (8.1% vs. 2.1%; OR = 3.37; 95% CI = 1.74-6.50; p < 0.0001), and RDHF (6.62% vs. 0.92%; OR = 9.46; 95% CI = 4.65-19.24; p < 0.0001). Notably, major adverse cardiovascular events (MACE) exhibited a stronger association with Hs-cTnT levels (18.2% vs 7.81%; OR = 1.89; 95% CI = 0.80-4.43; I2 = 97%; p = 0.14) compared to Hs-cTnI levels (20.1% vs 21.1%; OR = 1.30; 95% CI = 1.03-1.64; I2 <0.0001%; p = 0.03).

CONCLUSION

Elevated levels of Hs-cTnT (>14 ng/L) are significantly associated with increased risks of RDHF and ACM in patients with stable CAD. Further large-scale prospective studies are warranted to refine risk assessment strategies and mitigate cardiovascular mortality in this population.

Reference intervals of circulating secretoneurin concentrations determined in a large cohort of community dwellers: the HUNT study

OBJECTIVES

Secretoneurin (SN) is a novel cardiac biomarker that associates with the risk of mortality and dysfunctional cardiomyocyte Ca2+ handling in heart failure patients. Reference intervals for SN are unknown.

METHODS

SN was measured with a CE-marked ELISA in healthy community dwellers from the fourth wave of the Trøndelag Health Study (HUNT4) conducted in 2017-2019. The common, sex and age specific 90th, 95th, 97.5th and 99th percentiles were calculated using the non-parametric method and outlier exclusion according to the Reed test. The applicability of sex and age specific reference intervals were investigated using Harris and Boyd test. We also estimated the percentiles in a subset with normal findings on echocardiographic screening.

RESULTS

The total cohort included 887 persons (56.4 % women). After echocardiographic screening 122 persons were excluded, leaving a total of 765 persons (57.8 % women). The 97.5th percentile (95 % CI in brackets) of SN was 59.7 (57.5-62.1) pmol/L in the total population and 58.6 (57.1-62.1) pmol/L after echocardiography screening. In general, slightly higher percentiles were found in women and elderly participants, but less than 4 % in these subgroups had concentrations deviating from the common 97.5th percentile. Low BMI or eGFR was also associated with higher concentrations of SN.

CONCLUSIONS

Upper reference limits for SN were similar amongst healthy adult community dwellers regardless of prescreening including cardiac echocardiography or not. Women and elderly showed higher concentrations of SN, but the differences were not sufficiently large to justify age and sex stratified upper reference limits.

High sensitivity troponins and mortality in the population with metabolic dysfunction-associated steatotic liver disease

Given the global high prevalence of MASLD and its poor CVD prognosis, it is essential to perform risk stratification for MASLD patients. The specific impact of High Sensitivity Troponins (hs-cTn ) on mortality in MASLD patients remains unexplored.  The NHANES databases from 1999 to 2004, which include data on high-sensitivity cardiac troponin (hs-cTn) levels and comorbidities, were linked with the most recent mortality dataset. Myocardial injury was determined using the 99th upper reference limits (URL) for hs-cTn.  Our study included 3460 MASLD patients. The mean follow-up duration was 192 months, during which 1074 (23%) MASLD participants died from all-cause mortality, and 363 (7.3%) died from CVD mortality. Our findings indicate that MASLD patients with elevated levels of hs-cTnT (> 99th URL) exhibit increased risks of all-cause mortality [adjusted hazard ratio (aHR) = 1.93] and CVD mortality (aHR = 2.4). Similar results were observed for hs-cTnI, where the aHRs for all-cause mortality and CVD mortality were 2.03 and 2.97, respectively. Furthermore, we identified a nonlinear dose-response relationship between hs-cTn levels and the risk of mortality (P for nonlinearity < 0.001).  Our findings suggest that hs-cTn can predict mortality risk in MASLD, aiding clinicians in risk-stratifying this population. Therefore, we recommend considering hs-cTn detection in individuals with MASLD to effectively assess their future mortality risk.

Individual and Joint Associations of High-Sensitivity Troponin I and High-Sensitivity Troponin T with Cardiac Phenotypes and Outcomes in the General Population: An Analysis From the Dallas Heart Study

BACKGROUND

High-sensitivity troponin I (hs-cTnI) and T (hs-cTnT) provide complementary information regarding cardiovascular disease risk. The explanation for their distinct risk profiles is incompletely understood.

METHODS AND RESULTS

hs-cTnI and hs-cTnT were measured in Dallas Heart Study participants. Associations of hs-cTnI and hs-cTnT with demographics and phenotypes were assessed using linear regression. Associations with incident heart failure, atherosclerotic cardiovascular disease, global cardiovascular disease, and cardiovascular and all-cause mortality were assessed using Cox models. Among 3276 participants (56% women, 50% Black persons, median age 43 years), the correlation between hs-cTnI and hs-cTnT was modest (Spearman rho=0.35). Variables associated with hs-cTnI but not hs-cTnT included hypertension, higher body mass index and total cholesterol, and lower high-density lipoprotein and cholesterol efflux capacity. Older age, male sex, and diabetes were positively associated, and smoking was negatively associated, with hs-cTnT but not hs-cTnI. Hs-cTnI and hs-cTnT were associated with heart failure (hazard ratio [HR] per SD log hs-cTnI 1.53 [95% CI, 1.30-1.81] and HR per SD log hs-cTnT 1.65 [95% CI, 1.40-1.95]), global cardiovascular disease (HR, 1.22 [95% CI, 1.10-1.34] and HR, 1.27 [95% CI, 1.15-1.32]), and all-cause mortality (HR, 1.12 [95% CI, 1.01-1.25], and HR, 1.17 [95% CI, 1.06-1.29]). After adjustment for N-terminal pro-B-type natriuretic peptide and the alternative troponin, both remained associated with heart failure (HR per SD log hs-cTnI 1.32 [95% CI, 1.1-1.58] and HR per log hs-cTnT 1.27 [95% CI, 1.06-1.51]).

CONCLUSIONS

Hs-cTnI and hs-cTnT are modestly correlated, demonstrate differential associations with cardiac and metabolic phenotypes, and provide complementary information regarding heart failure risk.

The relationship between workload and exercise-induced cardiac troponin elevations is influenced by non-obstructive coronary atherosclerosis

The relationship between exercise-induced troponin elevation and non-obstructive coronary artery disease (CAD) is unclear. This observational study assessed non-obstructive CAD's impact on exercise-induced cardiac Troponin I (cTnI) elevation in middle-aged recreational athletes. cTnI levels of 40 well-trained recreational athletes (73% males, 50 ± 9 years old) were assessed by a high-sensitive cTnI assay 24 h before, and at 3 and 24 h following two high-intensity exercises of different durations; a cardiopulmonary exercise test (CPET), and a 91-km mountain bike race. Workload was measured with power meters. Coronary computed tomography angiography was used to determine the presence or absence of non-obstructive (<50% obstruction) CAD. A total of 15 individuals had non-obstructive CAD (Atherosclerotic group), whereas 25 had no atherosclerosis (normal). There were higher post-exercise cTnI levels following the race compared with CPET, both at 3 h (77.0 (35.3-112.4) ng/L vs. 11.6 (6.4-22.5) ng/L, p < 0.001) and at 24 h (14.7 (6.7-16.3) vs. 5.0 (2.6-8.9) ng/L, p < 0.001). Absolute cTnI values did not differ among groups. Still, the association of cTnI response to power output was significantly stronger in the CAD versus Normal group both at 3 h post-exercise (Rho = 0.80, p < 0.001 vs. Rho = -0.20, p = 0.33) and 24-h post-exercise (Rho = 0.87, p < 0.001 vs. Rho = -0.13, p = 0.55). Exercise-induced cTnI elevation was strongly correlated with exercise workload in middle-aged athletes with non-obstructive CAD but not in individuals without CAD. This finding suggests that CAD influences the relationship between exercise workload and the cTnI response even without coronary artery obstruction.

Prognostic significance of chronic myocardial injury diagnosed by three different cardiac troponin assays in patients admitted with suspected acute coronary syndrome

OBJECTIVES

Chronic myocardial injury (CMI) is defined as stable concentrations of cardiac troponin T or I (cTnT or cTnI) above the assay-specific 99th percentile upper reference limit (URL) and signals poor outcome. The clinical implications of diagnosing CMI are unclear. We aimed to assess prevalence and association of CMI with long-term prognosis using three different high-sensitivity cTn (hs-cTn) assays.

METHODS

A total of 1,292 hospitalized patients without acute myocardial injury had cTn concentrations quantified by hs-cTn assays by Roche Diagnostics, Abbott Diagnostics and Siemens Healthineers. The median follow-up time was 4.1 years. The prevalence of CMI and hazard ratios for mortality and cardiovascular (CV) events were calculated based on the URL provided by the manufacturers and compared to the prognostic accuracy when lower percentiles of cTn (97.5, 95 or 90), limit of detection or the estimated bioequivalent concentrations between assays were used as cutoff values.

RESULTS

There was no major difference in prognostic accuracy between cTnT and cTnI analyzed as continuous variables. The correlation between cTnT and cTnI was high (r=0.724-0.785), but the cTnT assay diagnosed 3.9-4.5 times more patients with having CMI based on the sex-specific URLs (TnT, n=207; TnI Abbott, n=46, TnI Siemens, n=53) and had higher clinical sensitivity and AUC at the URL.

CONCLUSIONS

The prevalence of CMI is highly assay-dependent. cTnT and cTnI have similar prognostic accuracy for mortality or CV events when measured as continuous variables. However, a CMI diagnosis according to cTnT has higher prognostic accuracy compared to a CMI diagnosis according to cTnI.

Four high sensitivity troponin assays and mortality in US adults with cardiovascular disease: The national health and nutrition examination survey, 1999-2004

Objective

High sensitivity cardiac troponin (hs-cTn) may be useful to monitor residual risk in secondary prevention. Our objective was to study the correlations and comparative associations with mortality of four hs-cTn assays in US adults with known cardiovascular disease (CVD).

Methods

We studied 1,211 adults with a history of CVD who participated in the National Health and Nutrition Examination Survey (NHANES) 1999-2004. Using stored samples, we measured hs-cTnT (Roche) and three hs-cTnI assays (Abbott, Siemens, and Ortho). Outcomes were all-cause and CVD mortality, with follow-up through December 31, 2019.

Results

Mean age was 64 years, 48 % were female, and 80 % identified as non-Hispanic White. Pearson's correlation coefficients between hs-cTn assays ranged from 0.67 to 0.85. There were 848 deaths (365 from CVD). Among adults with a history of prior non-fatal CVD, each hs-cTn assay (log-transformed, per 1-SD) was independently associated with CVD death (HRs ranging from 1.55 to 2.16 per 1-SD, all p-values <0.05) and with all-cause death (HRs ranging from 1.31 to 1.62 per 1-SD, all p-values <0.05). Associations of hs-cTnT and all-cause and CVD death remained significant after adjusting for hs-cTnI (and vice versa). Associations between hs-cTnI and CVD death remained significant after mutually adjusting for other individual hs-cTnI assays: e.g., HR 2.21 (95 % CI 1.60, 3.05) for Ortho (hs-cTnI) after adjustment for Siemens (hs-cTnI) and HR 1.81 (95 % CI 1.35, 2.43) for Ortho (hs-cTnI) after adjustment for Abbott (hs-cTnI).

Conclusion

In US adults with a history of CVD, we found modest correlations between 4 hs-cTn assays. All assays were associated with all-cause and CVD mortality. The hs-cTnT assay was associated with mortality independent of the hs-cTnI assays. Hs-cTnI assays also appeared to be independent of each other. Thus, hs-cTn assays may provide distinct information for residual risk in secondary prevention adults.

Distribution and prognostic value of high-sensitivity cardiac troponin T and I across glycemic status: a population-based study

BACKGROUND

Whether distributions and prognostic values of high-sensitivity cardiac troponin (hs-cTn) T and I are different across normoglycemic, prediabetic, and diabetic populations is unknown.

METHODS

10127 adult participants from the National Health and Nutrition Examination Survey 1999-2004 with determined glycemic status and measurement of at least one of hs-cTn assays were included, from whom healthy participants and presumably healthy diabetic and prediabetic participants were selected to investigate pure impacts of glycemic status on distributions of hs-cTn. The nonparametric method and bootstrapping were used to derive the 99th upper reference limits of hs-cTn and 95% CI. Participants with available follow-up and hs-cTn concentrations of all 4 assays were included in prognostic analyses. Associations of hs-cTn with all-cause and cardiac-specific mortality were modeled by Cox proportional hazard regression under the complex survey design. The incremental value of hs-cTn to an established risk score in predicting cardiac-specific mortality was assessed by the 10-year area under time-dependent receiver operating characteristic curve (AUC) using the Fine-Grey competing risk model.

RESULTS

Among 9714 participants included in prognostic analyses, 5946 (61.2%) were normoglycemic, 2172 (22.4%) prediabetic, and 1596 (16.4%) diabetic. Hyperglycemic populations were older than the normoglycemic population but sex and race/ethnicity were similar. During the median follow-up of 16.8 years, hs-cTnT and hs-cTnI were independently associated with all-cause and cardiac-specific mortality across glycemic status. In the diabetic population, adjusted hazard ratios per 1-standard deviation increase of log-transformed hs-cTnT and hs-cTnI (Abbott) concentrations were 1.77 (95% CI 1.48-2.12; P < .001) and 1.83 (95% CI 1.33-2.53; P < .001), respectively, regarding cardiac-specific mortality. In the diabetic but not the normoglycemic population, adding either hs-cTnT (difference in AUC: 0.062; 95% CI 0.038-0.086; P < 0.001) or hs-cTnI (Abbott) (difference in AUC: 0.071; 95% CI 0.046-0.097; P < 0.001) would significantly increase the discriminative ability of the risk score; AUC of the score combined with hs-cTnT would be further improved by incorporating hs-cTnI (0.018; 95%CI 0.006-0.029; P = 0.002). The 99th percentile of hs-cTnT of the presumably healthy diabetic population was higher than the healthy population and had no overlap in 95% CIs, however, for hs-cTnI 99th percentiles of the two populations were very close and 95% CIs extensively overlapped.

CONCLUSIONS

Hs-cTnT and hs-cTnI demonstrated consistent prognostic associations across glycemic status but incremental predictive values in hyperglycemic populations only. The susceptibility of hs-cTnT 99th percentiles to diabetes plus the additive value of hs-cTnI to hs-cTnT in diabetic cardiovascular risk stratification suggested hs-cTnI and hs-cTnT may be differentially associated with glycemic status, but further research is needed to illustrate the interaction between hyperglycemia and hs-cTn.

Cardiac Troponin in Patients With Light Chain and Transthyretin Cardiac Amyloidosis: JACC: CardioOncology State-of-the-Art Review

Cardiac amyloidosis (CA) is an infiltrative disease caused by amyloid fibril deposition in the myocardium; the 2 forms that most frequently involve the heart are amyloid light chain (AL) and amyloid transthyretin (ATTR) amyloidosis. Cardiac troponin (cTn) is the biomarker of choice for the detection of myocardial injury and is frequently found to be elevated in patients with CA, particularly with high-sensitivity assays. Multiple mechanisms of myocardial injury in CA have been proposed, including cytotoxic effect of amyloid precursors, interstitial amyloid fibril infiltration, coronary microvascular dysfunction, amyloid- and non-amyloid-related coronary artery disease, diastolic dysfunction, and heart failure. Regardless of the mechanisms, cTn values have relevant prognostic (and potentially diagnostic) implications in both AL and ATTR amyloidosis. In this review, the authors discuss the significant aspects of cTn biology and measurement methods, potential mechanisms of myocardial injury in CA, and the clinical application of cTn in the management of both AL and ATTR amyloidosis.

The liver-heart axis in patients with severe obesity: The association between liver fibrosis and chronic myocardial injury may be explained by shared risk factors of cardiovascular disease

BACKGROUND

Severe obesity is associated with increased risk of non-alcoholic fatty liver disease and cardiovascular disease. We hypothesized that liver fibrosis as quantified by the Enhanced Liver Fibrosis (ELF) test would be predictive of myocardial injury and fibrosis, expressed by higher concentrations of cardiac troponin T and I measured by high-sensitivity assays (hs-cTnT and hs-cTnI, respectively).

MATERIAL AND METHODS

We performed cross-sectional analyses of baseline data from 136 patients (mean age 45 years, 38 % male) with severe obesity participating in the non-randomized clinical trial Prevention of Coronary Heart Disease in Morbidly Obese Patients (ClinicalTrials.gov NCT00626964). Associations between ELF scores, hs-cTnT, and hs-cTnI concentrations were assessed using linear regression analysis.

RESULTS

ELF scores were associated with hs-cTnT in the unadjusted model (B 0.381, 95 % Confidence Interval [CI] 0.247, 0.514), but the association was attenuated upon adjustment for potential confounders (B -0.031, 95 % CI -0.155, 0.093). Similarly, for hs-cTnI, an observed association with ELF scores in the unadjusted model was attenuated upon adjustment for potential confounders ((B 0.432, 95 % CI 0.179, 0.685) and (B 0.069, 95 % CI -0.230, 0.367), respectively). Age, sex, hypertension, and estimated glomerular filtration rate were amongst the shared predictors of ELF score, hs-cTnT, and hs-cTnI that provided the univariable models with the highest R-squared and lowest Akaike Information Criterion values.

CONCLUSIONS

Contrary to our hypothesis, ELF score did not predict myocardial injury and fibrosis, but we rather demonstrated an association between liver fibrosis and myocardial injury and fibrosis may be explained by shared risk factors of cardiovascular disease.

The association between higher cardiac troponin levels and the development of left ventricular diastolic dysfunction in septic patients with diabetes mellitus

This study was designed to retrospectively analyze the relationship between the levels of cardiac troponin T (cTnT) and cardiac troponin I (cTnI) and the development of left ventricular diastolic dysfunction (LVDD) in septic patients with diabetes mellitus. Furthermore, the predictive value of cTnT and cTnI in the LVDD development in those patients was investigated. The clinical information of 159 septic patients with diabetes mellitus treated in the intensive care unit of Affiliated Hospital of Chengde Medical University from June 2016 to January 2023 were retrospectively analyzed. These patients were separated into LVDD group (LVFP > 15 mmHg) and non-LVDD group (LVFP ≤ 15 mmHg) based on left ventricular filling pressure (LVFP). The differences in clinical data, echocardiographic parameters, as well as cTnT and cTnI levels between the LVDD and non-LVDD groups were compared. The relationship between the cTnT and cTnI levels and the echocardiographic parameters was studied using Pearson correlation analysis. Logistic regression analysis was conducted to explore the factors that influenced the LVDD development in septic patients with diabetes. Receiver operator characteristic (ROC) curves were created to evaluate the predictive value of cTnT and cTnI levels for the LVDD development in septic patients with diabetes. Totally 159 septic patients with diabetes were included in this study, with 97 patients in the LVDD group and 62 in the non-LVDD group. Compared with the non-LVDD group, patients in the LVDD group had much lower left ventricular (LV) early diastolic peak inflow velocity (E), LV advanced diastolic peak inflow velocity (A), E/A, and early diastolic mitral annular velocity (Em) while significantly higher E/Em. The LVDD group showed much higher levels of cTnI and cTnT than the non-LVDD group (P < 0.05). Significant positive correlation between log10cTnI level and E/Em ratio (r = 0.425, P < 0.001) was revealed by the Pearson correlation analysis. Multivariate analysis showed that E/A, E/Em, cTnI and cTnT were independent risk factors for the LVDD development in septic patients with diabetes (P < 0.05). As for ROC curve results, the area under the curve (AUC) of cTnT to predict the development of LVDD in septic patients with diabetes was 0.849 (95% CI 0.788-0.910, P < 0.001); the AUC of cTnI was 0.742 (95% CI 0.666-0.817, P < 0.001). Both cTnT and cTnI are independent risk factors and have predictive value for the LVDD development in septic patients with diabetes mellitus.

Biomarker-based prediction of fatal and non-fatal cardiovascular outcomes in individuals with diabetes mellitus

AIMS

The role of biomarkers in predicting cardiovascular outcomes in high-risk individuals is not well established. We aimed to investigate benefits of adding biomarkers to cardiovascular risk assessment in individuals with and without diabetes.

METHODS AND RESULTS

We used individual-level data of 95 292 individuals of the European population harmonized in the Biomarker for Cardiovascular Risk Assessment across Europe consortium and investigated the prognostic ability of high-sensitivity cardiac troponin I (hs-cTnI), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and high-sensitivity C-reactive protein (hs-CRP). Cox-regression models were used to determine adjusted hazard ratios of diabetes and log-transformed biomarkers for fatal and non-fatal cardiovascular events. Models were compared using the likelihood ratio test. Stratification by specific biomarker cut-offs was performed for crude time-to-event analysis using Kaplan-Meier plots. Overall, 6090 (6.4%) individuals had diabetes at baseline, median follow-up was 9.9 years. Adjusting for classical risk factors and biomarkers, diabetes [HR 2.11 (95% CI 1.92, 2.32)], and all biomarkers (HR per interquartile range hs-cTnI 1.08 [95% CI 1.04, 1.12]; NT-proBNP 1.44 [95% CI 1.37, 1.53]; hs-CRP 1.27 [95% CI 1.21, 1.33]) were independently associated with cardiovascular events. Specific cut-offs for each biomarker identified a high-risk group of individuals with diabetes losing a median of 15.5 years of life compared to diabetics without elevated biomarkers. Addition of biomarkers to the Cox-model significantly improved the prediction of outcomes (likelihood ratio test for nested models P < 0.001), accompanied by an increase in the c-index (increase to 0.81).

CONCLUSION

Biomarkers improve cardiovascular risk prediction in individuals with and without diabetes and facilitate the identification of individuals with diabetes at highest risk for cardiovascular events.

Blood-Based and Imaging Biomarkers of Atherosclerosis

Atherosclerosis is the main cause of arterial thrombosis, causing acute occlusive cardiovascular syndromes. Numerous risk prediction models have been developed, which mathematically combine multiple predictors, to estimate the risk of developing cardiovascular events. Current risk models typically do not include information from biomarkers that can potentially improve these existing prediction models especially if they are pathophysiologically relevant. Numerous cardiovascular disease biomarkers have been investigated that have focused on known pathophysiological pathways including those related to cardiac stress, inflammation, matrix remodelling, and endothelial dysfunction. Imaging biomarkers have also been studied that have yielded promising results with a potential higher degree of clinical applicability in detection of atherosclerosis and cardiovascular event prediction. To further improve therapy decision-making and guidance, there is continuing intense research on emerging biologically relevant biomarkers. As the pathogenesis of cardiovascular disease is multifactorial, improvements in discrimination and reclassification in risk prediction models will likely involve multiple biomarkers. This article will provide an overview of the literature on potential blood-based and imaging biomarkers of atherosclerosis studied so far, as well as potential future directions.

High-Sensitivity Cardiac Troponin for Risk Assessment in Patients With Chronic Coronary Artery Disease

BACKGROUND

Cardiac troponin is used for risk stratification of patients with acute coronary syndromes; however, the role of testing in other settings remains unclear.

OBJECTIVES

The aim of this study was to evaluate whether cardiac troponin testing could enhance risk stratification in patients with chronic coronary artery disease independent of disease severity and conventional risk measures.

METHODS

In a prospective cohort of consecutive patients with symptoms suggestive of stable angina attending for outpatient coronary angiography, high-sensitivity cardiac troponin I was measured before angiography, and clinicians were blinded to the results. The primary outcome was myocardial infarction or cardiovascular death during follow-up.

RESULTS

In 4,240 patients (age 66 years [IQR: 59-73 years], 33% female), coronary artery disease was identified in 3,888 (92%) who had 255 (6%) primary outcome events during a median follow-up of 2.4 years (IQR: 1.3-3.6 years). In patients with coronary artery disease, troponin concentrations were 2-fold higher in those with an event compared with those without (6.7 ng/L [IQR: 3.2-14.2 ng/L] vs 3.3 ng/L [IQR: 1.7-6.6 ng/L]; P < 0.001). Troponin concentrations were associated with the primary outcome after adjusting for cardiovascular risk factors and coronary artery disease severity (adjusted HR: 2.3; 95% CI: 1.7-3.0, log10 troponin; P < 0.001). A troponin concentration >10 ng/L identified patients with a 50% increase in the risk of myocardial infarction or cardiovascular death.

CONCLUSIONS

In patients with chronic coronary artery disease, cardiac troponin predicts risk of myocardial infarction or cardiovascular death independent of cardiovascular risk factors and disease severity. Further studies are required to evaluate whether routine testing could inform the selection of high-risk patients for treatment intensification. (Myocardial Injury in Patients Referred for Coronary Angiography [MICA]; ISRCTN15620297).

High-sensitivity troponins and mortality in the general population

AIMS

Cardiac troponin T and I can be measured using a number of high-sensitivity (hs) assays. This study aimed to characterize correlations between four such assays and test their comparative associations with mortality.

METHODS AND RESULTS

Among adults without cardiovascular disease in the 1999-2004 National Health and Nutrition Examination Survey, hs-troponin T was measured using one assay (Roche) and hs-troponin I using three assays (Abbott, Siemens, and Ortho). Cox regression was used to estimate associations with all-cause and cardiovascular mortality. Pearson's correlation coefficients comparing concentrations from each assay ranged from 0.53 to 0.77. There were 2188 deaths (488 cardiovascular) among 9810 participants. Each hs-troponin assay [log-transformed, per 1 standard deviation (SD)] was independently associated with all-cause mortality: hazard ratio (HR) 1.20 [95% confidence interval (CI) 1.13-1.28] for Abbott hs-troponin I; HR 1.10 (95% CI 1.02-1.18) for Siemens hs-troponin I; HR 1.23 (95% CI 1.14-1.33) for Ortho hs-troponin I; and HR 1.31 (95% CI 1.21-1.42) for Roche hs-troponin T. Each hs-troponin assay was also independently associated with cardiovascular mortality (HR 1.44 to 1.65 per 1 SD). Associations of hs-troponin T and all-cause and cardiovascular mortality remained significant after adjusting for hs-troponin I. Furthermore, associations of hs-troponin I remained significant after mutually adjusting for hs-troponin I from the other individual assays: e.g. cardiovascular mortality HR 1.46 (95% CI 1.19-1.79) for Abbott after adjustment for the Siemens assay and HR 1.29 (95% CI 1.09-1.53) for Abbott after adjustment for the Ortho assay.

CONCLUSION

This study demonstrates only modest correlations between hs-troponin T and three hs-troponin I assays and that hs-troponin I assays can provide distinct risk information for mortality in the general population.

Trajectories of cardiac troponin in the decades before cardiovascular death: a longitudinal cohort study

BACKGROUND

High-sensitivity cardiac troponin testing is a promising tool for cardiovascular risk prediction, but whether serial testing can dynamically predict risk is uncertain. We evaluated the trajectory of cardiac troponin I in the years prior to a cardiovascular event in the general population, and determine whether serial measurements could track risk within individuals.

METHODS

In the Whitehall II cohort, high-sensitivity cardiac troponin I concentrations were measured on three occasions over a 15-year period. Time trajectories of troponin were constructed in those who died from cardiovascular disease compared to those who survived or died from other causes during follow up and these were externally validated in the HUNT Study. A joint model that adjusts for cardiovascular risk factors was used to estimate risk of cardiovascular death using serial troponin measurements.

RESULTS

In 7,293 individuals (mean 58 ± 7 years, 29.4% women) cardiovascular and non-cardiovascular death occurred in 281 (3.9%) and 914 (12.5%) individuals (median follow-up 21.4 years), respectively. Troponin concentrations increased in those dying from cardiovascular disease with a steeper trajectory compared to those surviving or dying from other causes in Whitehall and HUNT (Pinteraction < 0.05 for both). The joint model demonstrated an independent association between temporal evolution of troponin and risk of cardiovascular death (HR per doubling, 1.45, 95% CI,1.33-1.75).

CONCLUSIONS

Cardiac troponin I concentrations increased in those dying from cardiovascular disease compared to those surviving or dying from other causes over the preceding decades. Serial cardiac troponin testing in the general population has potential to track future cardiovascular risk.

The clinical importance of high-sensitivity cardiac troponin measurements for risk prediction in non-cardiac surgery

INTRODUCTION

The global healthcare burden associated with surgery is substantial, with many patients experiencing perioperative complications. Cardiac troponin I and T measured with high-sensitivity assays are cardiac specific biomarkers that associate closely with adverse outcomes in most patient populations. Perioperative physiological stress can induce troponin release from cardiomyocytes, a condition known as perioperative myocardial injury (PMI). PMI is associated with increased risk of poor short- and long-term outcomes, and current European guidelines recommend screening for PMI in at-risk individuals undergoing non-cardiac surgery.

AREAS COVERED

In this review we summarize current knowledge of the prognostic attributes of cardiac troponins, as well as the challenges associated with their application as biomarkers in the perioperative phase.

EXPERT OPINION

Measurement of circulating levels of cardiac troponins identify individuals at increased risk of poor postoperative outcomes. Systematic screening of at-risk individuals undergoing non-cardiac surgery will result in a large proportion of patients in need of further diagnostic workup to establish the exact nature of their PMI. The lack of concrete evidence of clinical benefit and the increased cost associated with such a strategy is concerning and underscore the need for further research.

Can high-sensitive troponin levels within the normal range predict positivity in treadmill test?

BACKGROUND

This study aimed to determine whether a high level of high-sensitivity troponin T (hsTnT) predicts a positive treadmill test in patients with suspected stable ischemic heart disease (SIHD).

METHODS

In all, 366 patients with suspected SIHD were included in the study. We measured the serum hsTnT levels before the treadmill test. The treadmill test was performed according to the Bruce protocol.

RESULTS

Of the 366 patients, 97 had positive treadmill tests. The hsTnT levels were significantly higher in the positive group than in the negative group. In the binary logistic regression analysis, hsTnT, pretest probability, metabolic equivalents (METs), target heart rate (THR) percentage, and Duke treadmill score (DTS) were independent predictors of a positive treadmill test [hsTnT odds ratio (OR): 2.178, P  < 0.001; pretest probability OR: 1.036, P  = 0.007; METs OR: 0.755, P  = 0.008; THR OR: 0.773, P  < 0.001; DTS OR: 2.661, P  = 0.012]. In the receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) value of the model with the combined parameters of hsTnT, pretest probability, METs, THR, and DTS was statistically significant in predicting a positive treadmill test [combined model AUC: 0.945 (0.922-0.968), P  < 0.001].

CONCLUSIONS

In sum, high pretest hsTnT levels predicted a positive treadmill test in patients with suspected SIHD. Analysis of the hsTnT levels before the treadmill test can increase the sensitivity and specificity of the treadmill test. The methods for measuring hsTnT levels are cheap and easily accessible and can be used before the treadmill test in patients with suspected SIHD.

Chronic troponin elevation assessed by myocardial T1 mapping in patients with stable coronary artery disease

BACKGROUND

Cardiac troponin detected with sensitive assays can be chronically elevated, in the absence of unstable coronary syndromes. In patients with chronic coronary artery disease, clinically silent ischemic episodes may cause chronic troponin release. T1 mapping is a cardiovascular magnetic resonance technique useful in quantitative cardiac tissue characterization. We selected patients with anatomically and functionally normal hearts to investigate associations between chronic troponin release and myocardial tissue characteristics assessed by T1 mapping.

METHODS

We investigated the relationship between cardiac troponin I concentrations and cardiovascular magnetic resonance T1 mapping parameters in patients with stable coronary artery disease enrolled in MASS V study before elective revascularization. Participants had no previous myocardial infarction, negative late gadolinium enhancement, normal left ventricular function, chamber dimensions and wall thickness.

RESULTS

A total of 56 patients were analyzed in troponin tertiles: nativeT1 and extracellular volume (ECV) values (expressed as means ± standard deviations) increased across tertiles: nativeT1 (1006 ± 27 ms vs 1016 ± 27 ms vs 1034 ± 37 ms, ptrend = 0.006) and ECV (22 ± 3% vs 23 ± 1.9% vs 25 ± 3%, ptrend = 0.007). Cardiac troponin I concentrations correlated with native T1(R = 0.33, P = .012) and ECV (R = 0.3, P = .025), and were independently associated with nativeT1 (P = .049) and ventricular mass index (P = .041) in multivariable analysis.

CONCLUSION

In patients with chronic coronary artery disease and structurally normal hearts, troponin I concentrations correlated with T1 mapping parameters, suggesting that diffuse edema or fibrosis scattered in normal myocardium might be associated with chronic troponin release.

Differences between high-sensitivity cardiac troponin T and I in stable populations: underlying causes and clinical implications

OBJECTIVES

Measurement of high-sensitivity (hs) cardiac troponin (cTn) T and I is widely studied for cardiac assessment of stable populations. Recent data suggest clinical and prognostic discrepancies between both hs-cTn. We aimed at reviewing published studies with respect to underlying causes and clinical implications.

CONTENT

We summarized current evidence on release and clearance mechanisms of cTnT and I, and on preanalytical and assay-related issues potentially portending to differences in measured concentrations. We also performed a systematic review of outcome studies comparing both hs-cTn in the general population, patients with congestive heart failure, stable coronary artery disease and atrial fibrillation.

SUMMARY AND OUTLOOK

For the interpretation of concentrations of hs-cTnT, stronger association with renal dysfunction compared to hs-cTnI should be considered. Hs-cTnT also appears to be a stronger indicator of general cardiovascular morbidity and all-cause mortality. Hs-cTnI concentrations tend to be more sensitive to coronary artery disease and ischemic outcomes. These findings apparently reflect variations in the mechanisms of cardiac affections resulting in cTn release. Whether these differences are of clinically relevance remains to be elucidated. However, having the option of choosing between either hs-cTn might represent an option for framing individualized cardiac assessment in the future.

What Is the Clinical Utility of Cardiac Troponins in Heart Failure? Are They Modifiable Beyond Their Prognostic Value?

PURPOSE OF REVIEW

To review the role of cardiac troponin (cTn) for prognosis in acute and chronic heart failure, and for predicting heart failure; and to explore the association between troponin and response to heart failure therapies, with an eye toward a possible role for troponin in a personalized approach to heart failure management, beyond prognosis.

RECENT FINDINGS

A number of therapies, including the neprilysin inhibitor sacubitril/valsartan and sodium-glucose cotransporter-2 inhibitors, have recently been shown to improve outcomes in heart failure patients. Most studies suggest that these agents improve outcomes regardless of baseline cTn concentration, but have greater absolute benefit among patients with highest cTn and baseline risk. Troponin is prognostic across the heart failure spectrum, but whether it can significantly help with heart failure prevention and with tailoring and guiding heart failure treatments and interventions remains unknown.

Clinical implications of cardiac troponin-I in patients with hypertensive crisis visiting the emergency department

OBJECTIVES

Cardiac troponin-I (cTnI) is a representative marker of myocardial injury. Elevation of cTnI is frequently observed in patients with hypertensive crisis, but few studies have examined its prognostic significance in hypertensive crisis. We aimed to determine whether cTnI could predict all-cause mortality in patients with hypertensive crisis visiting the emergency department (ED).

METHODS

This observational study included patients aged ≥18 years who visited an ED between 2016 and 2019 for hypertensive crisis, defined as systolic blood pressure (BP) ≥180 mmHg and/or diastolic BP ≥110 mmHg. Among 6467 patients, 3938 who underwent a cTnI assay were analysed.

RESULTS

Among the 3938 patients, 596 (15.1%) had cTnI levels above the 99th percentile upper reference limit (elevated cTnI >40 ng/L) and 600 (15.2%) had cTnI levels between the detection limit (≥10 ng/L) and the 99th percentile upper reference limit (detectable cTnI). The 3-year all-cause mortality in the elevated, detectable and undetectable cTnI groups were 41.6%, 36.5% and 12.8%, respectively. After adjusting for confounding variables, elevated cTnI patients (adjusted hazard ratio [HR], 2.01; 95% confidence interval [CI], 1.61-2.52) and detectable cTnI patients (adjusted HR, 1.64; 95% CI, 1.32-2.04) showed a significantly higher risk of 3-year all-cause mortality than did patients with undetectable cTnI.

CONCLUSIONS

In patients with hypertensive crisis, elevated cTnI levels provide useful prognostic information and permit the early identification of patients with an increased risk of death. Moreover, putatively normal but detectable cTnI levels also significantly correlated with a higher risk of all-cause mortality. Intensive treatment and follow-up strategies are needed for patients with hypertensive crisis with elevated and detectable cTnI levels.Key messagesCardiac troponin-I level was an independent prognostic factor for all-cause mortality in patients with hypertensive crisis.Detectable but normal range cardiac troponin-I, which was considered clinically insignificant, also had a prognostic impact on all-cause mortality comparable to elevated cardiac troponin-I levels.

Investigation of hs-TnI and sST-2 as Potential Predictors of Long-Term Cardiovascular Risk in Patients with Survived Hospitalization for COVID-19 Pneumonia

Introduction: COVID-19 survivors reveal an increased long-term risk for cardiovascular disease. Biomarkers like troponins and sST-2 improve stratification of cardiovascular risk. Nevertheless, their prognostic value for identifying long-term cardiovascular risk after having survived COVID-19 has yet to be evaluated. Methods: In this single-center study, admission serum biomarkers of sST-2 and hs-TnI in a single cohort of 251 hospitalized COVID-19 survivors were evaluated. Concentrations were correlated with major cardiovascular events (MACE) defined as cardiovascular death and/or need for cardiovascular hospitalization during follow-up after hospital discharge [FU: 415 days (403; 422)]. Results: MACE was a frequent finding during FU with an incidence of 8.4% (cardiovascular death: 2.8% and/or need for cardiovascular hospitalization: 7.2%). Both biomarkers were reliable indicators of MACE (hs-TnI: sensitivity = 66.7% & specificity = 65.7%; sST-2: sensitivity = 33.3% & specificity = 97.4%). This was confirmed in a multivariate proportional-hazards analysis: besides age (HR = 1.047, 95% CI = 1.012−1.084, p = 0.009), hs-TnI (HR = 4.940, 95% CI = 1.904−12.816, p = 0.001) and sST-2 (HR = 10.901, 95% CI = 4.509−29.271, p < 0.001) were strong predictors of MACE. The predictive value of the model was further improved by combining both biomarkers with the factor age (concordance index hs-TnI + sST2 + age = 0.812). Conclusion: During long-term FU, hospitalized COVID-19 survivors, hs-TnI and sST-2 at admission, were strong predictors of MACE, indicating both proteins to be involved in post-acute sequelae of COVID-19.

Diagnostic and prognostic performance of the ratio between high-sensitivity cardiac troponin I and troponin T in patients with chest pain

Background

Elevations of high-sensitivity cardiac troponin (hs-cTn) concentrations not related to type 1 myocardial infarction are common in chest pain patients presenting to emergency departments. The discrimination of these patients from those with type 1 myocardial infarction (MI) is challenging and resource-consuming. We aimed to investigate whether the hs-cTn I/T ratio might provide diagnostic and prognostic increment in this context.

Methods

We calculated the hs-cTn I/T ratio in 888 chest pain patients having hs-cTnI (Abbott Laboratories) or hs-cTnT (Roche Diagnostics) concentrations above the respective 99^th percentile at 2 hours from presentation. All patients were followed for one year regarding mortality.

Results

The median hs-cTn I/T ratio was 3.45 (25^th, 75^th percentiles 1.80–6.59) in type 1 MI patients (n = 408 ☯46.0%]), 1.18 (0.81–1.90) in type 2 MI patients (n = 56 ☯6.3%]) and 0.67 (0.39–1.12) in patients without MI. The hs-cTn I/T ratio provided good discrimination of type 1 MI from no type 1 MI (area under the receiver-operator characteristic curve 0.89 ☯95% confidence interval 0.86–0.91]), of type 1 MI from type 2 MI (area under the curve 0.81 ☯95% confidence interval 0.74–0.87]), and was associated with type 1 MI in adjusted analyses. The hs-cTn I/T ratio provided no consistent prognostic value.

Conclusions

The hs-cTn I/T ratio appears to be useful for early diagnosis of type 1 MI and its discrimination from type 2 MI in chest pain patients presenting with elevated hs-cTn. Differences in hs-cTn I/T ratio values may reflect variations in hs-cTn release mechanisms in response to different types of myocardial injury.

Association of High-Sensitivity Troponin T and I Blood Concentrations With All-Cause Mortality and Cardiovascular Outcome in Stable Patients-Results From the INTERCATH Cohort

Background The association between high-sensitivity troponin T (hsTnT) and high-sensitivity troponin I (hsTnI) and outcome when adjusted for confounders including the angiographical severity of coronary artery disease (CAD) remains largely unknown. We therefore aimed to explore whether hsTnT and hsTnI blood levels increase with CAD severity and add independent predictive information for future major adverse cardiovascular events and all-cause mortality in stable patients. Methods and Results Patients from the INTERCATH cohort with available coronary angiography and hsTnT and hsTnI concentrations were included. Troponin concentrations were quantified via hsTnT (Roche Elecsys) and hsTnI (Abbott ARCHITECT STAT). To investigate the association of hsTnT and hsTnI with outcome, a multivariable analysis adjusting for classical cardiovascular risk factors, low-density lipoprotein cholesterol, estimated glomerular filtration rate, hs-CRP (high-sensitivity C-reactive protein), NT-proBNP (N-terminal pro-brain natriuretic peptide), and Gensini score was carried out. Of 1829 patients, 27.9% were women, and the mean age was 68.6±10.9 years. Troponin blood concentrations were higher in patients with diagnosed CAD compared with those without. Using a linear regression model current smoking, arterial hypertension, estimated glomerular filtration rate, hs-CRP, NT-proBNP, and CAD severity as graded by the Gensini and SYNTAX scores were associated with high-sensitivity troponin levels. Patients were followed for 4.4 years (25th and 75th percentiles: 4.3, 4.4). After multivariable adjustment, all-cause mortality was predicted by hsTnT (hazard ratio [HR], 1.7 [95% CI, 1.5-2.2], P<0.001) as well as hsTnI (HR, 1.5 [95% CI, 1.2-1.8], P<0.001). However, only hsTnI (HR, 1.2 [95% CI, 1.0-1.4], P=0.032) remained as an independent predictor of major adverse cardiovascular events after adjusting for most possible confounders, including CAD severity (hsTnT: HR, 1.0 [95% CI, 0.9-1.2], P=0.95). Conclusions After adjusting for classical cardiovascular risk factors, low-density lipoprotein cholesterol, estimated glomerular filtration rate, hs-CRP, NT-proBNP, and CAD severity, hsTnT and hsTnI were independently associated with all-cause mortality, but only hsTnI was associated with major adverse cardiovascular events in stable patients undergoing coronary angiography. Registration URL: https://clinicaltrials.gov/; Unique identifier: NCT04936438.

Multiplex Label-Free Kinetic Characterization of Antibodies for Rapid Sensitive Cardiac Troponin I Detection Based on Functionalized Magnetic Nanotags

Express and highly sensitive immunoassays for the quantitative registration of cardiac troponin I (cTnI) are in high demand for early point-of-care differential diagnosis of acute myocardial infarction. The selection of antibodies that feature rapid and tight binding with antigens is crucial for immunoassay rate and sensitivity. A method is presented for the selection of the most promising clones for advanced immunoassays via simultaneous characterization of interaction kinetics of different monoclonal antibodies (mAb) using a direct label-free method of multiplex spectral correlation interferometry. mAb-cTnI interactions were real-time registered on an epoxy-modified microarray glass sensor chip that did not require activation. The covalent immobilization of mAb microdots on its surface provided versatility, convenience, and virtually unlimited multiplexing potential. The kinetics of tracer antibody interaction with the “cTnI—capture antibody” complex was characterized. Algorithms are shown for excluding mutual competition of the tracer/capture antibodies and selecting the optimal pairs for different assay formats. Using the selected mAbs, a lateral flow assay was developed for rapid quantitative cTnI determination based on electronic detection of functionalized magnetic nanoparticles applied as labels (detection limit—0.08 ng/mL, dynamic range > 3 orders). The method can be extended to other molecular biomarkers for high-throughput screening of mAbs and rational development of immunoassays.

Metformin and high-sensitivity cardiac troponin I and T trajectories in type 2 diabetes patients: a post-hoc analysis of a randomized controlled trial

BACKGROUND

Metformin has favorable effects on cardiovascular outcomes in both newly onset and advanced type 2 diabetes, as previously reported findings from the UK Prospective Diabetes Study and the HOME trial have demonstrated. Patients with type 2 diabetes present with chronically elevated circulating cardiac troponin levels, an established predictor of cardiovascular endpoints and prognostic marker of subclinical myocardial injury. It is unknown whether metformin affects cardiac troponin levels. The study aimed to evaluate cardiac troponin I and T trajectories in patients with diabetes treated either with metformin or placebo.

METHODS

This study is a post-hoc analysis of a randomized controlled trial (HOME trial) that included 390 patients with advanced type 2 diabetes randomized to 850 mg metformin or placebo up to three times daily concomitant to continued insulin treatment. Cardiac troponin I and T concentrations were measured at baseline and after 4, 17, 30, 43 and 52 months. We evaluated cardiac troponin trajectories by linear mixed-effects modeling, correcting for age, sex, smoking status and history of cardiovascular disease.

RESULTS

This study enrolled 390 subjects, of which 196 received metformin and 194 received placebo. In the treatment and placebo groups, mean age was 64 and 59 years; with 50% and 58% of subjects of the female sex, respectively. Despite the previously reported reduction of macrovascular disease risk in this cohort by metformin, linear mixed-effects regression modelling did not reveal evidence for an effect on cardiac troponin I and cardiac troponin T levels [- 8.4% (- 18.6, 3.2), p = 0.150, and - 4.6% (- 12, 3.2), p = 0.242, respectively]. A statistically significant time-treatment interaction was found for troponin T [- 1.6% (- 2.9, - 0.2), p = 0.021] but not troponin I concentrations [- 1.5% (- 4.2, 1.2), p = 0.263].

CONCLUSIONS

In this post-hoc analysis of a 4.3-year randomized controlled trial, metformin did not exert a clinically relevant effect on cardiac troponin I and cardiac troponin T levels when compared to placebo. Cardioprotective effects of the drug observed in clinical studies are not reflected by a reduction in these biomarkers of subclinical myocardial injury. Trial registration ClinicalTrials.gov identifier NCT00375388.

Lifetime obesity trends are associated with subclinical myocardial injury: The Trøndelag health study

BACKGROUND

Obesity is associated with subclinical myocardial injury as quantified by concentrations of cardiac troponin T, but whether lifetime excess weight history is associated with increased concentrations of cardiac troponin I (cTnI) and how indices of abdominal adiposity and glycemic dysregulation affect these associations remain unclear.

METHODS

We analyzed cTnI with a high-sensitivity assay in 9739 participants in the Trøndelag Health (HUNT) Study at study visit 4 (2017-2019). BMI was assessed at study Visit 1 (1984-1986), 2 (1995-1997), 3 (2006-2008), and 4.

RESULTS

Median age at visit 4 was 68.7 years and 59% were women. Concentrations of cTnI were detectable in 84.1% of study participants, with a median of 2.5 (1.5-4.5 ng/L). We identified three clusters of BMI trajectories from visit 1 to 4, (1) stable normal weight, (2) stable overweight, and (3) stable obesity. Participants in clusters 2 and 3 were at increased risk of elevated concentrations of cTnI at visit 4 (odds ratio 1.27, 95% CI 1.09-1.47, and odds ratio 1.70, 95% CI 1.33-2.17, p for trend <0.001). Participants in cluster 3 had 22.0 (95% CI 14.1-29.9) higher concentrations of cTnI compared to participants in cluster 1 (p for trend <0.001). Dysregulated glucose metabolism and abdominal obesity did not influence our results.

CONCLUSIONS

Individuals with stable overweight or obesity are at increased risk of subclinical myocardial injury, independently of glycemic dysregulation and abdominal adiposity. Our data support a direct detrimental effect of long-standing obesity on cardiovascular health.

Effect of smoking cessation on cardiac troponin I concentrations

Chronic elevation of cardiac troponin I (cTnI) is associated with heart failure and cardiovascular death. Paradoxically, observational studies have indicated that current smokers have lower cTnI concentrations than non-smokers. We examined determinants of cTnI in smokers and the effect of smoking cessation on cTnI. Overweight or obese smokers received motivational support and varenicline to aid cessation and dietary advice to limit weight gain. Quitters were defined according to the Russell standard (≤5 cigarettes after the quit date) and validated with expired breath CO <10 ppm. Of the total 122 participants, 108 completed assessments at 12 weeks and 78 were classified as quitters versus 30 who continued smoking. cTnI was measured with a high-sensitivity assay with a limit of detection of 1.2 ng/L (Abbott Diagnostics), and concentrations (log-transformed) were compared between quitters and continuing smokers. cTnI concentrations were significantly higher in men than women and correlated with age, but not with number of cigarettes/day. Quitters had median baseline and 12-week levels of 1.4 ng/L (interquartile range [IQR] 1.2-2.5) and 1.4 ng/L (IQR 1.2-2.4), respectively, while nonquitters had baseline and 12-week levels of 1.5 ng/L (IQR 1.2-2.9) and 1.8 ng/L (IQR 1.3-3.4), respectively. The change in cTnI concentrations from baseline to 12 weeks did not differ between quitters and continuous smokers (p = .7). The results suggest that smoking cessation does not affect levels of cTnI, a marker of chronic subclinical myocardial injury, in contrast to prior observational data suggesting that tobacco smoking is associated with lower cTn concentrations.

Impact of Chronic Kidney Disease on the Associations of Cardiovascular Biomarkers With Adverse Outcomes in Patients With Suspected or Known Coronary Artery Disease: The EXCEED-J Study

Background

The impact of chronic kidney disease (CKD) on the prognostic utility of cardiovascular biomarkers in high‐risk patients remains unclear.

Methods and Results

We performed a multicenter, prospective cohort study of 3255 patients with suspected or known coronary artery disease (CAD) to investigate whether CKD modifies the prognostic utility of cardiovascular biomarkers. Serum levels of cardiovascular and renal biomarkers, including soluble fms‐like tyrosine kinase‐1 (sFlt‐1), N‐terminal pro‐brain natriuretic peptide (NT‐proBNP), high‐sensitivity cardiac troponin‐I (hs‐cTnI), cystatin C, and placental growth factor, were measured in 1301 CKD and 1954 patients without CKD. The urine albumin to creatinine ratio (UACR) was measured in patients with CKD. The primary outcome was 3‐point MACE (3P‐MACE) defined as a composite of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke. The secondary outcomes were all‐cause death, cardiovascular death, and 5P‐MACE defined as a composite of 3P‐MACE, heart failure hospitalization, and coronary/peripheral artery revascularization. After adjustment for clinical confounders, sFlt‐1, NT‐proBNP, and hs‐cTnI, but not other biomarkers, were significantly associated with 3P‐MACE, all‐cause death, and cardiovascular death in the entire cohort and in patients without CKD. These associations were still significant in CKD only for NT‐proBNP and hs‐cTnI. NT‐proBNP and hs‐cTnI were also significantly associated with 5P‐MACE in CKD. The UACR was not significantly associated with any outcomes in CKD. NT‐proBNP and hs‐cTnI added incremental prognostic information for all outcomes to the model with potential clinical confounders in CKD.

Conclusions

NT‐proBNP and hs‐cTnI were the most powerful prognostic biomarkers in patients with suspected or known CAD and concomitant CKD.

Cardiac troponin I and T for ruling out coronary artery disease in suspected chronic coronary syndrome

To compare the performance of high-sensitivity cardiac troponin I and T (hs-cTnI; hs-cTnT) in diagnosing obstructive coronary artery disease (CAD₅₀) in patients with suspected chronic coronary syndrome (CCS). A total of 706 patients with suspected CCS, referred for Coronary Computed Tomography Angiography, were included. cTn concentrations were measured using the Singulex hs-cTnI (limit of detection [LoD] 0.08 ng/L) and Roche hs-cTnT (LoD 3 ng/L) assays. Obstructive coronary artery disease (CAD₅₀) was defined as ≥ 50% coronary stenosis. Cardiovascular risk was determined by the NORRISK2-score. Median age of the patients was 65 (range 28-87) years, 35% were women. All patients had hs-cTnI concentrations above the LoD (median 1.9 [Q1-3 1.2-3.6] ng/L), 72% had hs-cTnT above the LoD (median 5 [Q1-3 2-11] ng/L). There was a graded relationship between hs-cTn concentrations and coronary artery calcium. Only hs-cTnI remained associated with CAD₅₀ in adjusted analyses (OR 1.20 95% Confidence Interval [1.05-1.38]), p = 0.009). The C-statistics for hs-cTnI and hs-cTnT were 0.65 (95% CI [0.60-0.69]) and 0.60 (0.56-0.64). The highest specificity and negative predictive values for CAD₅₀ were in the lowest NORRISK2-tertile. hs-cTn concentrations provide diagnostic information in patients with suspected CCS, with superior performance of hs-cTnI compared to hs-cTnT in regard to CAD₅₀. The diagnostic performance appeared best in those with low cardiovascular risk.

Tobacco Consumption and High-Sensitivity Cardiac Troponin I in the General Population: The HUNT Study

Background

Cardiac troponins represent a sensitive index of subclinical myocardial injury and are associated with increased risk of cardiovascular events in the general population. Despite positive associations with cardiovascular risk of both cardiac troponins and cigarette smoking, concentrations of cardiac troponin I measured by high‐sensitivity assays (hs‐cTnI) are paradoxically lower in current smokers than in never‐smokers. The impact of smoking intensity and time from smoking cessation on hs‐cTnI remains unknown.

Methods and Results

hs‐cTnI concentrations were measured in 32028 subjects free from cardiovascular disease enrolled in the prospective, population‐based HUNT (Trøndelag Health Study). Tobacco habits were self‐reported and classified as never (n=14 559), former (n=14 248), and current (n=3221) smokers. Current smokers exhibited significantly lower concentrations of hs‐cTnI than never‐smokers (P<0.001). In adjusted models, both current smoking (−17.3%; 95% CI, −20.6 to −13.9%) and former smoking (−6.6%; 95% CI, −8.7 to −4.5%) were associated with significantly lower hs‐cTnI concentrations. Among former smokers, higher smoking burden (>10 pack‐years) were associated with lower concentrations of hs‐cTnI. Time since smoking cessation was associated with increasing concentrations of hs‐cTnI in a dose‐dependent manner (P for trend<0.001), and subjects who quit smoking >30 years ago had concentrations of hs‐cTnI comparable with those of never‐smokers.

Conclusions

In the general population, both current and former cigarette smoking is associated with lower concentrations of hs‐cTnI. In former smokers, there was a dose‐response relationship between pack‐years of smoking, and hs‐cTnI. Time since smoking cessation was associated with increasing concentrations of hs‐cTnI, indicating a continuum of hs‐cTnI from current smoker to never‐smokers.

Elevated Myoglobin in Patients With Primary Aldosteronism: A Cross-Sectional Study

OBJECTIVES

Primary aldosteronism (PA) is characterized by the autonomous excessive production of aldosterone in the adrenal cortex. Aldosterone is associated with damages to heart muscle and skeletal muscle. The purpose of this study was to evaluate serum levels of muscle injury markers and their associated factors in patients with primary aldosteronism.

METHODS

We retrospectively enrolled subjects with PA and essential hypertension (EH) who had completed testing for serum high sensitivity troponin T (hs-TnT), creatine kinase isoenzyme MB (CK-MB) and myoglobin from the database of the Chongqing Primary Aldosteronism Study (CONPASS). Univariate and multivariate linear regression analyses were performed to analyze the influencing factors of myocardial injury markers.

RESULTS

In total, 278 patients with PA and 445 patients with EH were enrolled in this study. Compared with EH patients, serum concentrations of hs-TnT [7.0 (4.0-12.0) vs. 6.0 (3.0-11.0) ng/L; p=0.005] and myoglobin [24.2 (21.0-38.1) vs. 21.8 (21.0-31.9) μg/L; p=0.023] were significantly higher among PA patients, while no significant difference of CK-MB was found between two groups [1.4 (1.0-2.0) vs. 1.3 (0.9-1.9) μg/L; p=0.154]. Univariate linear regression analysis showed that myoglobin was negatively correlated with serum potassium (β=-0.31; p<0.01) and positively correlated with plasma aldosterone concentration (β=0.40; p<0.01) in the PA group, while no significant correlation was found between hs-TnT and biochemical parameters. After adjusting for multiple confounders, myoglobin was negatively correlated with serum potassium (β=-0.15; p<0.05) and positively correlated with plasma aldosterone concentration (β=0.34; p<0.01) in the PA group.

CONCLUSIONS

The serum level of myoglobin was significantly increased in PA patients, and myoglobin was independently correlated with plasma aldosterone concentration.

Effects of Metoprolol on Periprocedural Myocardial Infarction After Percutaneous Coronary Intervention (Type 4a MI): An Inverse Probability of Treatment Weighting Analysis

Background: Metoprolol is the most used cardiac selective β-blocker and has been recommended as a mainstay drug in the management of acute myocardial infarction (AMI). However, the evidence supporting this regimen in periprocedural myocardial infarction (PMI) is limited.

Methods: This study identified 860 individuals who suffered PMI following percutaneous coronary intervention (PCI) procedure and median followed up for 3.2 years. Subjects were dichotomized according to whether they received chronic oral sustained-release metoprolol succinate following PMI. After inverse probability of treatment weighting (IPTW) adjustment, logistic regression analysis, Kaplan-Meier curve, and Cox regression analysis were performed to estimate the effects of metoprolol on major adverse cardiovascular events (MACEs) which composed of cardiac death, myocardial infarction (MI), stroke, and revascularization. Moreover, an exploratory analysis was performed according to hypertension, cardiac troponin I (cTnI) elevation, and cardiac function. A double robust adjustment was used for sensitivity analysis.

Results: Among enrolled PMI subjects, 456 (53%) patients received metoprolol treatment and 404 (47%) patients received observation. After IPTW adjustment, receiving metoprolol was found to reduce the subsequent 3-year risk of MACEs by nearly 7.1% [15 vs. 22.1%, absolute risk difference (ARD) = 0.07, number needed to treat (NNT) = 14, relative risk (RR) = 0.682]. In IPTW-adjusted Cox regression analyses, receiving metoprolol was related to a reduced risk of MACEs (hazard ratio [HR] = 0.588, 95%CI [0.385–0.898], P = 0.014) and revascularization (HR = 0.538, 95%CI [0.326–0.89], P = 0.016). Additionally, IPTW-adjusted logistic regression analysis showed that receiving metoprolol reduced the risk of MI at the third year (odds ratio [OR] = 0.972, 95% CI [0.948–997], P = 0.029). Exploratory analysis showed that the protective effect of metoprolol was more pronounced in subgroups of hypertension and cTnI elevation ≥1,000%, and was remained in patients without cardiac dysfunction. The benefits above were consistent when double robust adjustments were performed.

Conclusion: In the real-world setting, receiving metoprolol treatment following PCI-related PMI has decreased the subsequent risk of MACEs, particularly the risk of recurrent MI and revascularization.

Troponin I as a Biomarker for Early Detection of Acute Myocardial Infarction

Acute myocardial infarction (AMI) as the main cause of death among cardiovascular diseases is defined as a deficiency of oxygen that generates irreversible tissue necrosis in the heart muscle. For diagnostic measurements, the evaluation of cardiac markers concentration like cardiac triponin I (cTnI) in plasma or saliva thought the use of biosensors has become one of the most commonly applied strategies for prognosis of AMI. Inside this diagnostic devices, electrochemical (ECL) ones have been highly encourage to improve sensing capabilities by using different materials and configurations. In this review, the authors presents a summary of studies that involves cTnI detection using ECL biosensors modified with nanomaterials and related mechanisms.

Use of Coronary CT Angiography to Predict Obstructive Lesions in Patients with Chest Pain without Enzyme and ST-Segment Elevation

It is challenging to rule out acute coronary syndrome among chest pain patients without both ST-segment elevation in electrocardiography and troponin elevation at emergency departments (ED). The purpose of this study was to develop a prediction model for rapidly determining the occurrence of significant stenosis in coronary computed tomography angiography (CCTA). Retrospective observational cohort study was conducted with 904 patients who had presented with chest pain without troponin elevation and ST-segment changes and underwent CCTA between January 2017 and December 2018. The primary endpoint was the presence of significant stenosis on CCTA, defined as narrowing above 70% diameter. The logistic regression model was used for development a new predictive model. One hundred and thirty-four patients (14.8%) were shown severe stenosis. The independent associated factors for significant stenosis were age ≥65 years, male, diabetes, history of acute coronary syndrome, and typical chest pain. Based these results, we developed a new prediction model. The area under the curve was 0.782 (95% confidence interval 0.742-0.822). Moreover, score of ≥5 was chosen as cut-off values with 86.6% sensitivity and 56.4% specificity. In conclusion, among chest pain patients without ST changes and troponin elevation, the new score will be helpful to identify potential candidate for CCTA such as patients with significant stenosis.

Factors associated with baseline and serial changes in circulating NT-proBNP and high-sensitivity cardiac troponin T in a population-based cohort (Dallas Heart Study)

Aim: N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) associate with structural heart disease and heart failure risk in individuals without known cardiovascular disease (CVD). However, few data are available regarding whether factors influencing levels of these two biomarkers are similar or distinct. We performed serial measurement of NT-proBNP and hs-cTnT in a contemporary multiethnic cohort with extensive phenotyping, with the goal of identifying their respective biological determinants in a population without known or suspected CVD. Methods: We evaluated 1877 participants of the Dallas Heart Study who had NT-proBNP and hs-cTnT measured and were free from clinical CVD at the each of its two examinations (2000-2002 and 2007-2009). Variables collected included demographic and risk factors, high-sensitivity C-reactive protein, body composition via dual-energy x-ray absorptiometry, coronary artery calcium by computed tomography, and cardiac dimensions and function by cardiac MRI. Linear regression was used to identify associations of these factors with each biomarker at baseline and with changes in biomarkers over follow-up. Results: NT-proBNP and hs-cTnT were poorly correlated at baseline (Spearman rho 0.083, p = 0.015), with only moderate correlation between change values (rho 0.18, p < 0.001). hs-cTnT positively associated and NT-proBNP inversely associated with male gender and black race. At baseline, both NT-proBNP and hs-cTnT associated with left ventricular end-diastolic volume and wall thickness, but only NT-proBNP associated with left atrial size. Changes in cardiac dimensions between phases were more strongly associated with changes in NT-proBNP than hs-cTnT. NT-proBNP was more strongly associated with high-sensitivity C-reactive protein and measures of body composition than hs-cTnT. Conclusion: Among individuals without CVD in the general population, NT-proBNP and hs-cTnT are nonredundant biomarkers that are differentially associated with demographic and cardiac factors. These findings indicate that hs-cTnT and NT-proBNP may reflect different pathophysiological pathways.

Association of Mortality-Related Risk Factors in Patients with COVID-19: A Retrospective Cohort Study

COVID-19 is a rapidly disseminating infectious disease conferred by the World Health Organization (WHO) as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological and clinical characteristics data have been identified for patients with COVID-19, but mortality-related risk factors and a comprehensive clinical course of disease in a developing country have not been specifically defined. This retrospective, single-center cohort study involved all successive inpatients having a positive COVID-19 polymerase chain reaction (PCR), with deceased or discharged clinical outcomes from 1 January to 10 May 2021. Data were extracted from electronic medical records on demographic, clinical, radiological, and laboratory findings as well as complications faced and treatment provided during follow-up, involving serial samples for viral RNA identification, and compared between the dead and survivors. To investigate the risk factors associated with in-hospital mortality, we employed the multivariate logistic regression model. In this study, 2048 patients were involved, 1458 of whom were discharged, and 590 died in hospital. More than half of patients were identified as male with old age being the potential risk factor of mortality. Exactly 94.8% of all patients presented with fever at the time of admission. Several comorbidities were present in the study population, with the most frequent comorbidity being cardiovascular diseases (1177 of 2048) and hypertension (975 of 2048) followed by cerebrovascular disease and diabetes mellitus. Mortality rates for infected patients were observed as higher in severe patients (46.3%) compared with non-severe cases (26.1%) during a follow-up. Multivariate regression analysis showed a significant association of in-hospital mortality of patients with older age, presence of hypertension and cardiovascular diseases as underlying comorbidities, increased level of cardiac troponin I and d-dimer concentration on admission, as well as septicemia and ARDS as a complication during illness. To minimize the risk of death in COVID19 patients, as well as the risk of severe complications, urgent public health measures should be properly planned and implemented on those vulnerable populations. To detect early manifestations of clinical problems, thorough and regular follow-up is warranted.

Genome-wide association study of cardiac troponin I in the general population

Circulating cardiac troponin proteins are associated with structural heart disease and predict incident cardiovascular disease in the general population. However, the genetic contribution to cardiac troponin I (cTnI) concentrations and its causal effect on cardiovascular phenotypes are unclear. We combine data from two large population-based studies, the Trøndelag Health Study and the Generation Scotland Scottish Family Health Study, and perform a genome-wide association study of high-sensitivity cTnI concentrations with 48 115 individuals. We further use two-sample Mendelian randomization to investigate the causal effects of circulating cTnI on acute myocardial infarction (AMI) and heart failure (HF). We identified 12 genetic loci (8 novel) associated with cTnI concentrations. Associated protein-altering variants highlighted putative functional genes: CAND2, HABP2, ANO5, APOH, FHOD3, TNFAIP2, KLKB1 and LMAN1. Phenome-wide association tests in 1688 phecodes and 83 continuous traits in UK Biobank showed associations between a genetic risk score for cTnI and cardiac arrhythmias, metabolic and anthropometric measures. Using two-sample Mendelian randomization, we confirmed the non-causal role of cTnI in AMI (5948 cases, 355 246 controls). We found indications for a causal role of cTnI in HF (47 309 cases and 930 014 controls), but this was not supported by secondary analyses using left ventricular mass as outcome (18 257 individuals). Our findings clarify the biology underlying the heritable contribution to circulating cTnI and support cTnI as a non-causal biomarker for AMI in the general population. Using genetically informed methods for causal inference helps inform the role and value of measuring cTnI in the general population.

Sortilin and Homocysteine as Potential Biomarkers for Coronary Artery Diseases

Purpose

The aim of this study was to assess the relationship of coronary artery disease (CAD) with levels of homocysteine and sortilin in Egyptian patients.

Background

CAD is a primary contributor to cardiac disease and a prominent cause of death globally.

Patients and Methods

We enrolled 45 patients with CAD evaluated by coronary CT angiography and 42 control subjects without CAD. Plasma-homocysteine and -sortilin levels were measured with a commercial ELISA kit.

Results

Elevated levels of homocysteine and sortilin were observed in the CAD patients compared to controls (13.75±1.40 vs 7.73±2.06 μmol/L, P=0 and 160.91±32.17 vs 143.02±32.30 ng/dL, P=0.02, respectively). Significantly higher total cholesterol, low density–lipoprotein cholesterol and triglycerides (P<0.05) and lower high density–lipoprotein cholesterol (P<0.05) were seen among patients with CAD than the control group. Sortilin levels were positively associated with homocysteine levels (r=0.32, P=0.006), total cholesterol (r=0.61, P=0), low density–lipoprotein cholesterol (r=0.37, P=0.001), triglycerides (r=0.91, P=0), troponin I (r=0.82, P=0), Gensini score (r=0.93, P=0) and high-sensitivity CRP (r=0.87, P=0) in all subjects. Homocysteine has a significantly negative association with high density–lipoprotein cholesterol (r=−0.42, P=0).

Conclusion

Elevated homocysteine and sortilin levels are crucial risk factors of CAD in Egyptian patients.