High-sensitivity cardiac troponin T for detection of subtle abnormalities of cardiac phenotype in a general population of elderly individuals

Intensive Blood Pressure Lowering in Individuals With Low Diastolic Blood Pressure and Elevated Troponin Levels in SPRINT

BACKGROUND

Among individuals with hypertension and low diastolic blood pressure (DBP), the optimal BP target remains controversial due to concerns that BP lowering may reduce coronary perfusion. We determined the impact of intensive BP control among individuals with elevated systolic BP who have low DBP and elevated hs-cTnT (high-sensitivity cardiac troponin T) levels.

METHODS AND RESULTS

A total of 8828 participants in SPRINT (Systolic Blood Pressure Intervention Trial) were stratified by baseline DBP. Those with low DBP (<70 mm Hg) were further stratified by elevated hs-cTnT (≥14 ng/L) at baseline. The effects of intensive versus standard BP lowering on a cardiovascular disease composite end point, all-cause death, and 1-year change in hs-cTnT were determined. The combination of low DBP/high hs-cTnT was independently associated with a higher risk for cardiovascular disease and all-cause death, as well as greater 1-year increases in hs-cTnT, compared with DBP ≥70 mm Hg. However, randomization to intensive versus standard BP lowering led to similar reductions in cardiovascular disease risk among individuals with low DBP/high hs-cTnT (hazard ratio [HR], 0.82 [95% CI, 0.57-1.19]), low DBP/low hs-cTnT (HR, 0.48 [95% CI, 0.29-0.79]), and DBP ≥70 mm Hg (HR, 0.73 [95% CI, 0.60-0.89]; P for interaction=0.20). Intensive BP lowering also led to a reduction in all-cause death that was similar across groups (P for interaction=0.57).

CONCLUSIONS

In this nonprespecified subgroup analysis of SPRINT, individuals with low DBP and elevated hs-cTnT, low DBP and nonelevated hs-cTnT, and DBP ≥70 mm Hg derived similar cardiovascular disease and mortality benefits from intensive BP lowering. These findings warrant confirmation in other studies.

Postoperative cardiac biomarker release is not associated with myocardial mass in computer tomography scans

OBJECTIVES

Myocardial hypertrophy results in increased levels of cardiac biomarkers in healthy individuals and in patients suffering from acute myocardial infarction. The influence of cardiac mass on postoperative cardiac biomarkers release remains unclear. This study investigated the correlation between myocardial mass and the release of high-sensitivity cardiac Troponin T (hs-cTnT) and creatine kinase-myocardial band (CK-MB) after isolated aortic valve replacement (AVR) or bypass surgery.

METHODS

Myocardial mass of a consecutive retrospective series of patients was measured automatically using preoperative computer tomography scans (636 patients, AVR = 251; bypass surgery = 385). Levels of cardiac biomarkers were measured before and serially after surgery. Spearman and Pearson correlation and a multivariate regression model was performed to measure the degree of association between myocardial mass and the release of hs-cTnT and CK-MB.

RESULTS

Patients were divided into 3 tertiles according to their myocardial mass index. Higher biomarker levels were measured preoperatively in the upper tertile of patients undergoing AVR (P = 0.004) or bypass surgery (P < 0.001). Patients with different heart sizes showed no differences in postoperative biomarker release neither after AVR nor bypass surgery. No statistical significant correlation was observed between myocardial mass index and postoperative release of hs-cTnT or CK-MB in any subgroup (ρ maximum 0.106).

CONCLUSIONS

Postoperative biomarker release is not correlated with myocardial mass. Patient factors leading to increased postoperative biomarker levels need to be elucidated in future studies.

IGFBP7 and GDF-15, but not P1NP, are associated with cardiac alterations and 10-year outcome in an elderly community-based study

Background

Little is known about the clinical value of Insulin-like growth factor-binding protein-7 (IGFBP7), a cellular senescence marker, in an elderly general population with multiple co-morbidities and high prevalence of asymptomatic cardiovascular ventricular dysfunction. Inflammation and fibrosis are hallmarks of cardiac aging and remodelling. Therefore, we assessed the clinical performance of IGFBP7 and two other biomarkers reflecting these pathogenic pathways, the growth differentiation factor-15 (GFD-15) and amino-terminal propeptide of type I procollagen (P1NP), for their association with cardiac phenotypes and outcomes in the PREDICTOR study.

Methods

2001 community-dwelling subjects aged 65–84 years who had undergone centrally-read echocardiography, were selected through administrative registries. Atrial fibrillation (AF) and 4 echocardiographic patterns were assessed: E/e’ (> 8), enlarged left atrial area, left ventricular hypertrophy (LVH) and reduced midwall circumference shortening (MFS). All-cause and cardiovascular mortality and hospitalization were recorded over a median follow-up of 10.6 years.

Results

IGFBP7 and GDF-15, but not P1NP, were independently associated with prevalent AF and echocardiographic variables after adjusting for age and sex. After adjustment for clinical risk factors and cardiac patterns or NT-proBNP and hsTnT, both IGFBP7 and GDF-15 independently predicted all-cause mortality, hazard ratios 2.13[1.08–4.22] and 2.03[1.62–2.56] per unit increase of Ln-transformed markers, respectively.

Conclusions

In a community-based elderly cohort, IGFBP7 and GDF-15 appear associated to cardiac alterations as well as to 10-year risk of all-cause mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02138-8.

Sex differences in factors associated with heart failure and diastolic left ventricular dysfunction: a cross-sectional population-based study

BACKGROUND

Although sex differences in cardiovascular diseases are recognised, including differences in incidence, clinical presentation, response to treatments, and outcomes, most of the practice guidelines are not sex-specific. Heart failure (HF) is a major public health challenge, with high health care expenditures, high prevalence, and poor clinical outcomes. The objective was to analyse the sex-specific association of socio-demographics, life-style factors and health characteristics with the prevalence of HF and diastolic left ventricular dysfunction (DLVD) in a cross-sectional population-based study.

METHODS

A random sample of 2001 65-84 year-olds underwent physical examination, laboratory measurements, including N-terminal pro-B-type natriuretic peptide (NT-proBNP), electrocardiography, and echocardiography. We selected the subjects with no missing values in covariates and echocardiographic parameters and performed a complete case analysis. Sex-specific multivariable logistic regression models were used to identify the factors associated with the prevalence of the diseases, multinomial logistic regression was used to investigate the factors associated to asymptomatic and symptomatic LVD, and spline curves to display the relationship between the conditions and both age and NT-proBNP.

RESULTS

In 857 men included, there were 66 cases of HF and 408 cases of DLVD (77% not reporting symptoms). In 819 women, there were 51 cases of HF and 382 of DLVD (79% not reporting symptoms). In men, the factors associated with prevalence of HF were age, ischemic heart disease (IHD), and suffering from three or more comorbid conditions. In women, the factors associated with HF were age, lifestyles (smoking and alcohol), BMI, hypertension, and atrial fibrillation. Age and diabetes were associated to asymptomatic DLVD in both genders. NT-proBNP levels were more strongly associated with HF in men than in women.

CONCLUSIONS

There were sex differences in the factors associated with HF. The results suggest that prevention policies should consider the sex-specific impact on cardiac function of modifiable cardiovascular risk factors.

Perioperative Cardiac Troponin I Levels in Patients Undergoing Total Hip and Total Knee Arthroplasty: A Single Center Study

Background

Cardiac injury is one of the significant perioperative complications in major orthopedic surgeries and its early diagnosis is useful in the reduction of postoperative comorbidity. The cardiac troponin is a sensitive and specific biomarker for detecting this damage.

Objectives

The aim of this study was to evaluate the levels of perioperative cardiac troponin I (cTnI) before and after arthroplasty in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). The effects of related variables and probable major cardiac complications were evaluated in this study.

Methods

For one year, in a prospective, cross-sectional study, the serum levels of cTnI before and 48 hours after arthroplasty were evaluated in 52 patients. Possible contributing factors including age, gender, body mass index (BMI), daily activity, history of hospitalization due to cardiovascular diseases, underlying illness, and medications were recorded. The Chi-square test, Pearson correlation, and Spearman test were used to examine the relationship between variables.

Results

The mean cTnI increased significantly after arthroplasty (P < 0.001). There was no significant relationship between age (P = 0.708), gender (P = 0.225), BMI (P = 0.195), daily activity (0.441), underlying illness (P = 0.244), and cTnI levels after arthroplasty. Linear regression showed BMI was significantly correlated with troponin changes (P = 0.006). Five patients had heart palpitations and one had chest pain, but none of the patients had any findings in favor of cardiac injury.

Conclusions

cTnI levels after THA and TKA increased significantly, but this elevation was in the normal range. In addition, none of them had a new cardiac complication after arthroplasty.

Impact of Sex on Cardiac Troponin Concentrations—A Critical Appraisal

BACKGROUND

The use of sex-specific cutoffs for cardiac troponin (cTn) is currently debated. Although endorsed by scientific working groups, concerns have been raised that sex-specific cutoffs may have only a small clinical effect at the cost of increased complexity in decision-making.

METHODS

We reviewed studies investigating the interrelations between high-sensitivity (hs) cTn results and sex, diagnoses, and outcome. Investigated populations included community-dwelling subjects and patients with stable angina, congestive heart failure, or acute chest pain including those with acute coronary syndromes.

RESULTS

Men usually have higher hs-cTn concentrations compared with women, regardless of the assessed population or the applied assay. The distribution and prognostic implications of hs-cTn concentrations indicate that women have a broader cardiovascular risk panorama compared with men, particularly at lower hs-cTn concentrations. At higher concentrations, particularly above the 99th percentile, this variation is often attenuated. Sex-specific hs-cTn 99th percentiles have so far shown clinical net benefit in only 1 study assessing patients with chest pain. However, several methodological aspects need to be considered when interpreting study results, e.g., issues related to the determination of the 99th percentiles, the selection bias, and the lack of prospective and sufficiently powered analyses.

CONCLUSIONS

Available studies do not show a consistent clinical superiority of sex-specific hs-cTn 99th percentiles. This may reflect methodological aspects. However, from a pathobiological perspective, the use of sex-specific hs-cTn 99th percentiles makes sense for the ruling in of myocardial infarction. We propose a new approach to hs-cTn 99th cutoffs taking into account the analytical properties of the used assays.

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

OBJECTIVE

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

SETTING

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

PARTICIPANTS

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

OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Elevated troponin I level assessed by a new high-sensitive assay and the risk of poor outcomes in patients with acute heart failure

BACKGROUND

The interpretation and clinical usefulness of elevated levels of cardiac troponins in acute heart failure (AHF) remain controversial. We aimed to characterize the relationship between changes in cardiac troponin I (measured using a new high-sensitive immunoassay by single-molecule counting technology, Singulex, Alameda, USA; hs-TnI) during first 48h of hospital stay and patients' characteristics and the outcomes.

METHODS AND RESULTS

We measured hs-TnI at baseline, after 24 and 48h in 130 AHF patients (mean age: 65±13years, 77% men). The percentage of patients with elevated hs-TnI (i.e., above the upper reference limit [URL]>10.19pg/mL) were: on admission - 59%, after 24h - 61%, and after 48h - 58%. Elevated baseline level of hs-TnI was associated with more severe dyspnoea on admission but neither peak level nor changes in hs-TnI during first 48h were related to the dyspnoea severity or magnitude of dyspnoea relief. During 1-year follow-up there were 32 (25%) cardiovascular deaths. Neither absolute baseline nor peak values of hs-TnI predicted cardiovascular mortality. Only changes in hs-TnI were independently associated with cardiovascular mortality with the strongest relationship seen in peak change in hs-TnI: patients with an increase vs. remaining patients - hazard ratio (95% confidence interval): 3.22 (1.52-6.82)p=0.002.

CONCLUSIONS

Using the new assay (proved to be more sensitive that the other available troponin assays) we observed that approximately 60% of patients with AHF presented elevated hs-TnI above URL during first 48h of hospital stay. Only significant increase in hs-TnI predicted cardiovascular mortality.

Usefulness of High-Sensitivity Cardiac Troponin T for the Identification of Outlier Patients With Diffuse Coronary Atherosclerosis and Low-Risk Factors

Novel high-sensitivity assay can detect very low levels of circulating cardiac troponin (hs-cTnT) in apparently healthy subjects. Within normal range, higher levels are associated with coronary artery disease (CAD) and cardiac abnormalities commonly associated to traditional risk factors (RFs) for CAD. Therefore, we investigated the relation between circulating hs-cTnT and CAD in patients with a spectrum of RF burden aiming to assess the added value of hs-cTnT to identify "outlier" patients with CAD despite a low RF burden. Hs-cTnT was measured in 525 stable patients without previous diagnosis of ischemic heart disease with 0 to 1 RF, excluded diabetes, (low-RF group, n = 263) or ≥2 RFs (multiple-RF group, n = 262) and without CAD (segment involvement score = 0) or diffuse CAD (segment involvement score >5) at coronary computed tomography angiography. Outlier patients with diffuse CAD despite low-RF burden had similar extent, severity, and plaque composition than patients with multiple RFs. Overall, hs-cTnT was measurable in 81% of patients with median value of 6.0 ng/L. In both groups, hs-cTnT concentration was higher in patients with CAD than in patients with normal coronary arteries (p <0.0001). Hs-cTnT was more accurate to detect patients with CAD in the low-RF group than in the multiple-RF group (p = 0.04). In multivariate analysis, higher level of hs-cTnT (>6 ng/L) was independently associated with CAD in low-RF group only. Despite very low circulating concentrations, hs-cTnT may identify with a good accuracy the outlier patients with diffuse CAD despite low-RF burden.

Prognostic Significance of High-Sensitivity Cardiac Troponin T Concentrations between the Limit of Blank and Limit of Detection in Community-Dwelling Adults: A Metaanalysis

BACKGROUND

There is controversy regarding whether to report concentrations of high-sensitivity cardiac troponin T (hs-cTnT) to the limit of blank (LOB) (3 ng/L) or the limit of detection (LOD) (5 ng/L) of the assay in community-based cohorts. We hypothesized that hs-cTnT concentrations between the LOB and LOD would be associated with poorer cardiovascular outcomes compared to concentrations below the LOB.

METHODS

hs-cTnT was analyzed in a total of 10 723 participants from the Cardiovascular Health Study (CHS), Atherosclerosis Risk in Communities (ARIC) study, and Dallas Heart Study (DHS). Participants were divided into 2 groups, those with hs-cTnT concentrations below the limit of blank (LOB) (<3 ng/L) and those with hs-cTnT between the LOB and limit of detection (LOD) (3-4.99 ng/L). Cross-sectional associations with traditional cardiovascular risk factors and cardiac structural measurements, and longitudinal associations with long-term cardiovascular outcomes of incident heart failure and cardiovascular death, were determined.

RESULTS

Participants with hs-cTnT between the LOB and LOD for all 3 cohorts were older, more likely to be male, and have a higher burden of cardiovascular risk factors and structural pathology. A metaanalysis of the 3 cohorts showed participants with hs-cTnT between the LOB and LOD were at increased risk of new-onset heart failure (hazard ratio, 1.18; 95% CI, 1.02-1.38) and cardiovascular mortality (hazard ratio, 1.29; 95% CI, 1.06-1.57).

CONCLUSIONS

hs-cTnT concentrations between the LOB and LOD (3-4.99 ng/L) are associated with a higher prevalence of traditional risk factors, more cardiac pathology, and worse outcomes than concentrations below the LOB (<3 ng/L).

Cardiovascular biomarkers and sex: the case for women

Measurement of biomarkers is a critical component of cardiovascular care. Women and men differ in their cardiac physiology and manifestations of cardiovascular disease. Although most cardiovascular biomarkers are used by clinicians without taking sex into account, sex-specific differences in biomarkers clearly exist. Baseline concentrations of many biomarkers (including cardiac troponin, natriuretic peptides, galectin-3, and soluble ST2) differ in men versus women, but these sex-specific differences do not generally translate into a need for differential sex-based cut-off points. Furthermore, most biomarkers are similarly diagnostic and prognostic, regardless of sex. Two potential exceptions are cardiac troponins measured by high-sensitivity assay, and proneurotensin. Troponin levels are lower in women than in men and, with the use of high-sensitivity assays, sex-specific cut-off points might improve the diagnosis of myocardial infarction. Proneurotensin is a novel biomarker that was found to be predictive of incident cardiovascular disease in women, but not men, and was also predictive of incident breast cancer. If confirmed, proneurotensin might be a unique biomarker of disease risk in women. With any biomarker, an understanding of sex-specific differences might improve its use and might also lead to an enhanced understanding of the physiological differences between the hearts of men and women.

Relationship between high-sensitivity cardiac troponin I and blood pressure among young and healthy adults

BACKGROUND

The aim of this study was to evaluate the relationship of cardiac troponin (cTn) levels with conventional and ambulatory blood pressure (BP) in young and healthy adults.

METHODS

We performed a population based cross-sectional analysis among 2,072 young and healthy adults aged 25-41 years free of cardiovascular disease and diabetes mellitus. cTnI was measured using a highly sensitive (hs) assay. The relationships of high sensitivity cardiac tropononin I (hs-cTnI) with office and 24-hour BP were assessed using multivariable regression analyses.

RESULTS

Median age was 37 years and 975 (47%) participants were male. hs-cTnI levels were detectable in 2,061 (99.5%) individuals. Median (interquartile range) hs-cTnI levels were 0.98 (0.71; 1.64) ng/L among men and 0.48 (0.33; 0.71) ng/L among women. Systolic BP, but not diastolic BP, gradually increased across hs-cTnI quartiles (118, 120, 121, and 122 mm Hg for conventional BP; P = 0.0002; 122, 123, 124, and 124 mm Hg for 24-hour BP, P = 0.0001). In multivariable linear regression analyses, the β estimates for systolic BP per 1-unit increase in log transformed hs-cTnI were 2.52 for conventional BP (P = 0.0001); 2.75 for 24-hour BP (P < 0.0001); 2.71 and 2.41 (P < 0.0001 and P = 0.0002) for day and nighttime BP, respectively. There was a significant relationship between hs-cTnI and the Sokolow-Lyon Index (odds ratio (95% confidence interval): 2.09 (1.37; 3.18), P < 0.001).

CONCLUSION

Using a hs assay, hs-cTnI was detectable in virtually all participants of a young and healthy population. hs-cTnI was independently associated with systolic BP and left ventricular hypertrophy.

Cardiac troponin I levels in an elderly population from the community--The implications of sex

OBJECTIVES

The importance of sex on cardiac troponin levels is increasingly recognized. We investigated whether the entities associated with troponin leakage and the prognostic consequences thereof would differ between elderly men and women from the community.

DESIGN AND METHODS

Cardiac troponin I (cTnI) levels were measured using a high-sensitivity assay (Abbott Laboratories) in 70-year old men (n = 502) and women (n = 502) from the PIVUS study. All study participants were followed up for 10 years regarding all-cause mortality and incident cardiovascular (CV) disease.

RESULTS

Median cTnI levels were 4.1 and 3.0 ng/L in men and women, respectively (p<0.001). By multiple linear regression, the relative contribution of lower left-ventricular ejection fraction and ischemic ECG changes to cTnI levels was greater in men compared to women. For other clinical and echocardiographic variables, similar associations were found. cTnI independently predicted all-cause mortality in men (n = 93 [18.5%]; hazard ratio [HR] 1.38 [1.12-1.70]) and women (n = 62 [12.4%]; HR 1.59 [1.11-2.28]) but not incident CV disease in subjects being CV healthy at baseline (n = 163/857). The interaction terms of sex on the associations of cTnI with both outcomes were non-significant. Sex-specific cut-offs did not improve prognostication. Variations in the pattern of entities associated with cTnI leakage had no impact on event rates.

CONCLUSIONS

We found some differences in the entities associated with higher cTnI levels in elderly community-dwelling men and women. However, this did not translate into differences in the associations of cTnI with adverse outcome.

Biomarkers of cardiomyocyte injury and stress identify left atrial and left ventricular remodelling and dysfunction: A population-based study

BACKGROUND/OBJECTIVES

The validation of effective screening tools for the identification of patients with subclinical myocardial remodelling is a major clinical need. Thus, we explored the associations of circulating biomarkers of cardiomyocyte injury and stress with subclinical cardiac remodelling and dysfunction, and with biomarkers reflecting collagen turnover.

METHODS

We randomly recruited 727 subjects from a general population (51.2% women; mean age 51.3 years). Measurements included echocardiographic left atrial (LA) and left ventricular (LV) structure and function, quantification of high sensitivity cardiac Troponin T (hs-cTnT), NT-proBNP, and biomarkers of collagen types I and III turnover.

RESULTS

In unadjusted and adjusted analyses, the prevalence of LA enlargement (LAE), LV hypertrophy (LVH) and LV diastolic dysfunction (LVDD) increased with higher hs-cTnT (P ≤ 0.031). NT-proBNP was independently associated with LVDD (P=0.009). Both biomarkers combined yielded significant integrated discrimination and net reclassification improvements (P ≤ 0.014 and P ≤ 0.009, respectively) for LAE, LVH and LVDD, over the conventional risk factors, and were independently and positively associated with biomarkers of collagen type I turnover. In a sensitivity analysis, after excluding participants with previous cardiac diseases, our findings remained consistent.

CONCLUSIONS

Our population-based study suggested that subclinical LV and LA remodelling were associated with hs-cTnT, and that, in combination with NT-proBNP, hs-cTnT showed incremental diagnostic utility over the conventional risk factors. Both biomarkers were associated with biomarkers of collagen type I turnover. Thus, biomarkers of cardiomyocyte microinjury and hemodynamic stress may stimulate fibrosis-related mechanisms and facilitate the diagnosis of subclinical LA and LV remodelling and dysfunction in the general population.

The fibroblast growth factor-23 and Vitamin D emerge as nontraditional risk factors and may affect cardiovascular risk

OBJECTIVES

Fibroblast growth factor-23 (FGF-23) and vitamin D are hormones involved in phosphate homoeostasis. They also directly influence cardiomyocyte hypertrophy. We examined whether the relationships between levels of vitamin D or FGF-23, cardiac phenotype and outcome were independent of established cardiac biomarkers in a large cohort of community-dwelling elderly subjects.

DESIGN AND SETTING

Plasma levels of FGF-23 and vitamin D were measured in 1851 men and women (65-84 years) resident in the Lazio region of Italy. Participants were referred to eight cardiology centres for clinical examination, electrocardiography, comprehensive Doppler echocardiography and blood sampling. All-cause mortality or hospitalizations were available after a median follow-up of 47 months with record linkage of administrative data.

RESULTS

Vitamin D deficiency (<20 ng mL(-1) ) was found in 72.3% of subjects, but FGF-23 levels were normal [74 (58-97) RU per mL]. After adjustment for cardiovascular risk factors and morbidities, low concentrations of vitamin D and high levels of FGF-23 were associated with a higher left ventricular (LV) mass index. Levels of FGF-23 [hazard ratio (HR) (95% confidence interval (CI)) 1.71 (1.28-2.28), P < 0.0001] but not vitamin D [0.76 (0.57-1.01), P = 0.08] were independently associated with mortality after adjustment for clinical risk factors and two cardiac markers together (N-terminal pro-brain natriuretic peptide and high-sensitivity cardiac troponin T), but did not predict hospital admission. People with above median values of FGF-23 and below median values of vitamin D had greater LV hypertrophy and higher mortality.

CONCLUSIONS

In community-dwelling elderly individuals with highly prevalent vitamin D deficiency, FGF-23 levels were associated with LV hypertrophy and predicted mortality independently of two robust cardiac biomarkers. A causal relationship was not demonstrated, but the hormones involved in mineral metabolism emerged as nontraditional risk factors and may affect cardiovascular risk.

Clinical implications of high-sensitivity cardiac troponin measurements in hospitalized medical patients

Background

The increased use of high sensitivity cardiac troponins (hs-cTn), have made the diagnosis of non-ST elevation myocardial infarction (MI) challenging, especially in complex medical patients, in whom the clinical presentation of MI is nonspecific and multiple comorbidities as well as non-ischemic acute conditions may account for elevated hs-cTn levels. The aim of this study was to assess the frequency of both elevated hs-cTn levels and dynamic changes in hospitalized patients.

Methods and Findings

We conducted a retrospective study identifying all patients hospitalized in the Internal Medicine Division of Rabin Medical Center, Israel between January 2011 to December 2011, for whom at least one hs-cTn T (hs-cTnT) measurement was obtained. Collected data included patient demographics, acute and chronic diagnosis, hs-cTnT and creatinine levels and date of death. Hs-cTnT levels were obtained in 5,696 admissions and was above the 99th percentile (> = 13 ng/L) in 61.6% of the measurements. A relative change of 50% or higher was observed in 24% of the admissions. Among those with elevated hs-cTnT levels, acute coronary syndromes (ACS) accounted for only 6.1% of acute diagnoses. Maximal hs-cTnT levels above 100 ng/L but not dynamic changes discriminated between ACS and non-ACS conditions (positive and negative predictive values of 12% and 96% respectively). The frequency of elevated hs-cTnT levels was age-dependent and over 75% of patients aged >70 years-old had levels above the 99th percentile. Multivariate analysis identified hs-cTnT levels higher than the 99th percentile, as an independent, strong predictor for 30-day mortality (OR 4.58 [2.8, 7.49], p<0.0001).

Conclusions

Elevated hs-cTnT levels together with dynamic changes are frequent findings among hospitalized patients and in most cases, are not related to the ACS diagnosis. These findings highlight the diagnostic challenge of ACS in this complex population. Further studies are needed in order to optimize the use of hs-cTnT measurements in hospitalized patients.

Sex-specific associations of established and emerging cardiac biomarkers with all-cause mortality in older adults: the ActiFE study

BACKGROUND

N-terminal pro B-type natriuretic peptide (NT-proBNP) has strong prognostic value for all-cause mortality in the general population. High-sensitivity assays now allow detection of cardiac troponins even in asymptomatic populations. We examined the association between NT-proBNP, high-sensitivity cardiac troponin T (hs-cTnT), and hs-cTnI and all-cause mortality in older adults.

METHODS

We conducted a longitudinal cohort study [Activity and Function in the Elderly in Ulm (ActiFE Ulm)] including 1506 community-dwelling adults ≥65 years old with NT-proBNP, hs-cTnT, and hs-cTnI measured at baseline. We evaluated the associations between log-transformed biomarker concentrations and 4-year total mortality, accounting for possible confounders, with Cox proportional hazards models.

RESULTS

We observed 125 deaths among 1422 participants (median follow-up 4 years). We detected effect modification by sex for all biomarkers (all P values <0.05) expressed as hazard ratio (HR) for death per 1-unit increment of ln(biomarker concentration) in women (n = 618, 37 deaths) compared with men (n = 804, 88 deaths): HR 2.97 (95% CI 2.04-4.33) vs 1.73 (1.40-2.13) for NT-proBNP; 3.67 (2.31-5.81) vs 2.15 (1.61-2.87) for hs-cTnT; and 3.32 (2.13-5.18) vs 1.92 (1.55-2.38) for hs-cTnI. Among 777 participants with undetectable hs-cTnT (<5 ng/L), hs-cTnI remained associated with all-cause mortality in age- and sex-adjusted analysis.

CONCLUSIONS

NT-proBNP, hs-cTnT, and hs-cTnI were independently associated with all-cause mortality in older adults. The strength of these associations varied between men and women, emphasizing the need for additional sex-specific research among older people.

The influence of age on serum concentrations of cardiac troponin I: results in rats, monkeys, and commercial sera

Cardiac troponins serve as serum biomarkers of myocardial injury. The current study examined the influence of age on serum concentrations of cardiac troponin I (cTnI). An ultrasensitive immunoassay was used to monitor cTnI concentrations in Sprague-Dawley (SD) rats and Erythrocebus patas monkeys of different ages. The mean cTnI concentrations were highest in 10-day-old rats compared to 25-, 40-, and 80-day-old SD rats. Cardiomyocyte remodeling was apparent in hearts from 10-day-old SD rats as evident by hypercellularity, irregularly shaped nuclei, and moderate numbers of myocytes undergoing mitosis and apoptosis. The mean concentration of cTnI in 5 newborn monkeys was considerably higher than that of three 1-year-old monkeys. Evidence of cardiomyocyte remodeling was also observed in these newborn hearts (loss of myofibrils and cytoplasmic vacuolation). Commercial animal serum samples were also analyzed. The concentrations of cTnI detected in fetal equine and porcine serum were considerably higher than that found in adult equine and porcine serum samples Likewise, fetal bovine serum had higher cTnI concentrations (>2,400 pg/ml) than did adult caprine and laprine samples (2.5-2.7 pg/ml). The present study found age-related differences in cTnI concentrations, with higher levels occurring at younger ages. This effect was consistent across several animal species.

Prenatal exposure to traffic-related air pollution and risk of early childhood cancers

Exposure to air pollution during pregnancy has been linked to the risk of childhood cancer, but the evidence remains inconclusive. In the present study, we used land use regression modeling to estimate prenatal exposures to traffic exhaust and evaluate the associations with cancer risk in very young children. Participants in the Air Pollution and Childhood Cancers Study who were 5 years of age or younger and diagnosed with cancer between 1988 and 2008 were had their records linked to California birth certificates, and controls were selected from birth certificates. Land use regression-based estimates of exposures to nitric oxide, nitrogen dioxide, and nitrogen oxides were assigned based on birthplace residence and temporally adjusted using routine monitoring station data to evaluate air pollution exposures during specific pregnancy periods. Logistic regression models were adjusted for maternal age, race/ethnicity, educational level, parity, insurance type, and Census-based socioeconomic status, as well as child's sex and birth year. The odds of acute lymphoblastic leukemia increased by 9%, 23%, and 8% for each 25-ppb increase in average nitric oxide, nitrogen dioxide, and nitrogen oxide levels, respectively, over the entire pregnancy. Second- and third-trimester exposures increased the odds of bilateral retinoblastoma. No associations were found for annual average exposures without temporal components or for any other cancer type. These results lend support to a link between prenatal exposure to traffic exhaust and the risk of acute lymphoblastic leukemia and bilateral retinoblastoma.

High-sensitive cardiac troponin T and its relations to cardiovascular risk factors, morbidity, and mortality in elderly men

BACKGROUND

Cardiac troponin is emerging as risk indicator in community-dwelling populations. In this study, we investigated the associations of cardiac troponin T (cTnT) to cardiovascular (CV) disease and outcome in elderly men.

METHODS

Cardiac troponin T was measured using a high-sensitive assay in 940 men aged 71 years participating in the Uppsala Longitudinal Study of Adult Men. We assessed both the cross-sectional associations of cTnT to CV risk factors and morbidities including cancer and the longitudinal associations to outcomes over 10 years of follow-up.

RESULTS

Cardiac troponin T levels were measurable in 872 subjects (92.8%). In the cross-sectional analyses, cTnT was associated to CV risk factors (diabetes, smoking, and obesity), renal dysfunction, CV disease including atrial fibrillation and coronary artery disease, and biomarkers of inflammation and left ventricular dysfunction. In the longitudinal analyses, cTnT independently predicted total mortality and CV events including stroke. The standardized adjusted hazard ratio regarding the composite CV end point was 1.5 (95% CI 1.3-1.8), P < .001, for men with prevalent CV disease and 1.2 (95% CI 1.0-1.4), P = .02, for men without. Cardiac troponin T improved discrimination metrics for all outcomes in the total population. This was mainly driven by the prognostic value of cTnT in subjects with prevalent CV disease.

CONCLUSIONS

In community-dwelling men, cTnT levels are associated to CV risk factors and morbidities and predict both fatal and nonfatal CV events. The relations to outcome are mainly seen in men with prevalent CV disease indicating that the prognostic value of cTnT in subjects free from CV disease is limited.