Association of high-sensitivity troponin T with left ventricular dysfunction in prediabetes

BACKGROUND

Impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) are an increasingly serious problem worldwide. Tissue Doppler imaging (TDI), a non-invasive technique, may evaluate both systolic and diastolic function during the first phases of cardiovascular disease (CVD). High-sensitivity cardiac troponin T (hs-cTnT) can detect subclinical myocardial injury in asymptomatic prediabetic patients.

AIM

We aimed to investigate the relationship between left ventricular (LV) function and hs-cTnT in prediabetic patients.

METHODS

Between 1 October 2021 and 1 October 2022, we recruited 96 prediabetic and an equal number of age- and gender-matched healthy volunteers prospectively. TDI was used to evaluate both systolic and diastolic functions. Hs-cTnT levels were obtained and compared between groups.

RESULTS

It was found that the values for mitral annular plane systolic excursion (MAPSE), E, the rapid filling wave, E/Em, and the peak annular velocities of systolic excursion in the ejection period (Sm) were all significantly higher in these patients compared to healthy individuals (p < .001). Hs-cTnT was an independent predictor of left ventricular diastolic dysfunction (LVDD) and left ventricular systolic dysfunction (LVSD) (odds ratio [OR] = 2.625, 95% confidence interval [CI] = 1.324-4.308, p < .001, and OR = 1.922, 95% CI = 0.454-3.206, p = .004).

CONCLUSIONS

Prediabetics had higher hs-cTnT levels than controls. We showed that LVSD and LVDD functions were negatively affected in prediabetic patients. Our results proved that hs-cTnT levels may be associated with subclinical LV dysfunction in prediabetes.

Protective effect of quercetin against 5-fluorouracil-induced cardiac impairments through activating Nrf2 and inhibiting NF-κB and caspase-3 activities

5-Fluorouracil (5-FU) is a chemotherapy used to treat many types of cancer. Cardiotoxicity is one of the common drawbacks of 5-FU therapy. Quercetin (Qu) is a bioflavonoid with striking biological activities. This research aimed to assess the ameliorative effect of Qu against 5-FU-mediated cardiotoxicity. Thirty-five rats were allocated into five groups: control group (normal saline), 5-FU group (30 mg/kg, intraperitoneally), Qu group (50 mg/kg, oral), 25 mg/kg Qu+5-FU group, and 50 mg/kg Qu+5-FU. The experimental animals were received the above-mentioned drugs for 21 days. Results showed that 5-FU significantly elevated creatine kinase, lactate dehydrogenase, serum cholesterol and triglyceride, and upregulated troponin and renin mRNA expression. Additionally, cardiac oxidant/antioxidant imbalance was evident in elevated oxidants (malondialdehyde and nitric oxide) and depleted antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione). 5-FU also downregulated the gene expression of nuclear factor erythroid 2-related factor 2. Furthermore, 5-FU significantly increased cardiac pro-inflammatory cytokines (tumor necrosis factor-alpha and interleukin-1 beta) and upregulated gene expression of nuclear factor kappa-B. 5-FU significantly enhanced cardiac apoptosis through upregulating caspase-3 expression and downregulating B-cell lymphoma 2. Immunohistochemical and histopathological examinations verified the above-mentioned findings. However, all these changes were significantly ameliorated in Qu pre-administered rats. Conclusively, Qu counteracted 5-FU-mediated cardiotoxicity through potent antioxidant, anti-inflammatory, and anti-apoptotic effects.

A comparison of echocardiographic and circulating cardiac biomarkers for predicting incident cardiovascular disease

Background

Echocardiographic measures are known predictors of cardiovascular disease (CVD) in the general population. This study compared the predictive value of such measures to that of circulating cardiac biomarkers for a composite cardiovascular disease outcome in an aging population.

Methods

In this prospective population-based cohort study, echocardiography was performed at baseline together with assessments of traditional CVD risk factors and circulating cardiac biomarkers, NT-proBNP and troponin I, in 1016 individuals all aged 70 years. Assessments were repeated at ages 75 and 80. A composite CVD outcome (myocardial infarction, heart failure or ischemic stroke) was charted over 15 years. All echocardiography variables, except for the E/A ratio, were analyzed on a continuous scale.

Results

Over 10 years, left atrial (LA) diameter, left ventricular mass index (LVMI) and high E/A ratio (>1.5) increased, while left ventricular ejection fraction (LVEF) remained unchanged. Using Cox proportional hazard analyses with time-updated variables for echocardiographic measures and traditional risk factors, an enlarged LA diameter and a low LVEF were independently related to incident CVD in 222 participants. The addition of LA diameter and LVEF to traditional risk factors increased the C-statistic by 1.5% (p = 0.008). However, the addition of troponin I and NT-proBNP to traditional risk factors increased the C-statistic by 3.0% (p<0.001).

Conclusion

An enlarged LA diameter and a low LVEF improved the prediction of incident CVD compared to traditional risk factors. However, given that troponin I and NT-proBNP improved prediction to a similar extent, the use of simple blood tests to improve clinical cardiovascular disease risk prediction is only further supported by this study.

Elevated Admission Cardiac Troponin I Predicts Adverse Outcomes of Acute Type B Aortic Dissection after Endovascular Treatment

Background

There is a lack of evidence about the predictive role of serum cardiac troponin I (cTnI) on the long-term adverse outcomes of acute type B aortic dissection (aTBAD) patients after thoracic endovascular aortic repair (TEVAR). In this study, we identified whether cTnI was an independent risk factor of 5-year adverse outcomes for aTBAD patients after TEVAR.

Methods

We reviewed consecutive aTBAD patients without previous heart disease who were admitted for TEVAR. The total study population was divided into the cTnI(+) group (≥0.03 ng/mL) and the cTnI(−) group (<0.03 ng/mL) according to the time-dependent receiver operating characteristic curve analysis. The differences in clinical characteristics, operative details and clinical outcomes were compared between the two groups.

Results

There was no difference in age and male prevalence between the two groups. Compared with the cTnI(−) group, the incidence of chronic kidney disease was higher in patients with cTnI ≥0.03 ng/mL. In addition, the cTnI(+) group presented with more frequent premature beats and non-myocardial-infarction ST-T segment changes. In terms of laboratory examinations, white blood cell counts, neutrophil counts, serum D-dimer and serum fibrin degradation products showed an increase in the cTnI(+) group, while lymphocyte and platelet counts showed a decrease in these patients. Patients with elevated cTnI suffered from increased risks of 5-year aortic-related adverse events (hazard ratio, HR = 1.822, 95% confidence interval, CI: 1.094–3.035; p = 0.021) and all-cause mortality (HR = 4.009, 95% CI: 2.175–7.388; p < 0.001).

Conclusion

Among aTBAD patients without previous heart disease, preoperative elevated cTnI identified patients at an increased risk of long-term adverse outcomes after TEVAR.

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

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

Troponins in Heart Failure - a Perpetual Challenge

Increased troponin levels in HF are a frequent and significant finding, as it strongly correlates with the underlying pathogenic mechanisms, diagnosis and prognosis. The advent of hs-cTn testing, as opposed to conventional troponin testing, led to additional difficulties in result interpretation. Most frequently, though not exclusively, increased cTn levels in acute or chronic failure is correlated, with myocardial necrosis (AMI); the diagnosis of AMI is confirmed if other criteria are fulfilled, as described in the fourth Universal Definition of Myocardial Infarction. Increased cTn levels below the cut-off for AMI suggest acute or chronic injury, depending on the ascending and/or descending trend curve or stable levels of cTn on serial testing. In acute or chronic HF with reduced or preserved EF, increased cTn levels carry prognostic value for adverse outcomes. Acute and chronic HF, as well as other ischemic or non-ischemic conditions, may lead to a transient increase in cTn levels: hypertensive crises, tachyarrhythmias, valvular regurgitation, myocarditis, stroke, mandating differential diagnosis with ACS. There are multiple mechanisms that explain increased levels of cTn: myocardial necrosis or coronary thrombosis (type I MI), supply-demand mismatch with subendocardial ischemia/injury, cardiomyocyte apoptosis, inflammatory cytokines, neurohomonal changes. Screening for cTn levels in the population at high cardiovascular risk yields prognostic information on development of de novo HF or other cardiovascular adverse events.

High-Sensitivity Troponin T and Incident Heart Failure in Older Men: British Regional Heart Study

OBJECTIVE

The aim of this work was to study the association of high-sensitivity troponin T (hsTnT) with incident heart failure (HF), and implications for its use in prediction models.

METHODS AND RESULTS

In the British Regional Heart Study, 3852 men aged 60-79years without baseline HF (3165 without baseline chronic heart disease) were followed for a median of 12.6years, during which 295 incident cases of HF occurred (7.7%). A 1-SD increase in log-transformed hsTnT was associated with a higher risk of incident HF after adjusting for classic risk factors (hazard ratio [HR] 1.58, 95% confidence interval [CI] 1.42-1.77) and after additional adjustment for N-terminal pro-B-type natriuretic peptide (NT-proBNP; HR 1.34, 95% CI 1.19-1.52). The strength of the association between hsTnT and incident HF did not differ by strata of other risk factors. An hsTnT concentration of <5ng/L had a sensitivity of 99.7% (95% CI 98.1%-99.9%) and a specificity of 3.4% (95% CI 2.8%-4.0%). A risk-prediction model including classic risk factors and NT-proBNP yielded a C-index of 0.791, but addition of hsTnT did not further improve prediction (P = .28).

CONCLUSIONS

Elevated hsTnT is consistently associated with risk of HF in older men. HF occurred rarely over 12years when baseline hsTnT was below the limit of detection. hsTnT measurement, however, does not improve HF prediction in a model already containing NT-proBNP.

SYKT Alleviates Doxorubicin-Induced Cardiotoxicity via Modulating ROS-Mediated p53 and MAPK Signal Pathways

Backgrounds. Doxorubicin (DOX) is an effective therapeutic drug for malignant tumors; however, its clinical applications were limited by its side effects, especially the cardiotoxicity caused by ROS-mediated p53 and MAPK signal pathways' activation-induced cell apoptosis. Sanyang Xuedai mixture (SYKT) has been reported as an antioxidant agent and attenuated DOX-induced cardiotoxicity by targeting ROS-mediated apoptosis, but the mechanisms are still not fully delineated. Objective. This study aimed at investigating whether SYKT alleviated DOX-induced cardiotoxicity by inhibiting ROS-mediated apoptosis and elucidating the role of ROS-mediated p53 and MAPK signal pathways' activation in this process. Materials and Methods. Identification, separation, and culture of mouse primary cardiomyocytes. Cells were treated with DOX (1 μM), SYKT (30 mg/mL), or SYKT coupled with DOX. The p53 inhibitor Pifithrin-α (PFT-α), p38/MAPK inhibitor SB203583 (SB), and JNK inhibitor SP600125 (SP) were used as positive control. Western blot was employed to detected p53 and p38 as well as JNK expressions and the activation and translocation of Bax and cytochrome C. Flow cytometer (FCM) was used to detect the mitochondrial membrane potential and cell apoptosis. Results. After separation and culture, 95% of cells showed positive cTnI expression, which indicated that mouse primary cardiomyocytes were successfully identified in our research. DOX activated p53 and MAPK signal pathways in a time-dependent manner, which were inactivated by being cotreated with SYKT, PFT-α, or SB, respectively. DOX significantly decreased Bax and increased cytochrome c expressions in the cytoplasm, whereas Bax was upregulated and cytochrome c was downregulated in the mitochondria, which were reversed by SYKT treatment. Besides, DOX reduced mitochondria membrane potential (MMP) in cardiomyocytes compared to the control group; SYKT recovered its MMP and attenuated DOX-induced cardiomyocyte injury. Of note, DOX increased the expression levels of cleaved caspase-3 as well as poly ADP-ribose polymerase (PARP) and promoted cell apoptosis, which were also reversed by SYKT treatment. Discussion and Conclusions. Our results indicated that SYKT alleviated DOX-induced cardiotoxicity by inhibiting p53 and MAPK signal pathways' activation-mediated apoptosis, and it might serve as a potential therapeutic agent for DOX-induced cardiotoxicity.

Weight Loss and Heart Failure: A Nationwide Study of Gastric Bypass Surgery Versus Intensive Lifestyle Treatment

BACKGROUND

Associations of obesity with incidence of heart failure have been observed, but the causality is uncertain. We hypothesized that gastric bypass surgery leads to a lower incidence of heart failure compared with intensive lifestyle modification in obese people.

METHODS

We included obese people without previous heart failure from a Swedish nationwide registry of people treated with a structured intensive lifestyle program and the Scandinavian Obesity Surgery Registry. All analyses used inverse probability weights based on baseline body mass index and a propensity score estimated from baseline variables. Treatment groups were well balanced in terms of weight, body mass index, and most potential confounders. Associations of treatment with heart failure incidence, as defined in the National Patient Register, were analyzed with Cox regression.

RESULTS

The 25 804 gastric bypass surgery patients had on average lost 18.8 kg more weight after 1 year and 22.6 kg more after 2 years than the 13 701 lifestyle modification patients. During a median of 4.1 years, surgery patients had lower heart failure incidence than lifestyle modification patients (hazard ratio, 0.54; 95% confidence interval, 0.36-0.82). A 10-kg achieved weight loss after 1 year was related to a hazard ratio for heart failure of 0.77 (95% confidence interval, 0.60-0.97) in both treatment groups combined. Results were robust in sensitivity analyses.

CONCLUSIONS

Gastric bypass surgery was associated with approximately one half the incidence of heart failure compared with intensive lifestyle modification in this study of 2 large nationwide registries. We also observed a graded association between increasing weight loss and decreasing risk of heart failure.

Renocardiovascular Biomarkers: from the Perspective of Managing Chronic Kidney Disease and Cardiovascular Disease

Mortality among the patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) remains high because of the very high incidence of cardiovascular disease (CVD) such as coronary artery disease, cardiac hypertrophy, and heart failure. Identifying CVD in patients with CKD/ESRD remains a significant hurdle and the early diagnosis and therapy for CVD is crucial in these patients. Therefore, it is necessary for the better management to identify and utilize cardiovascular (CV) biomarkers in profiling CVD risk and enabling stratification of early mortality. This review summarizes current evidence about renocardiovascular biomarkers: CV biomarkers in patients with CKD as well as with ESRD, emphasizing on the emerging biomarkers: B-type natriuretic peptide, cardiac troponins, copeptin, the biomarker of renal injury (neutrophil gelatinase-associated lipocalin), and the mineral and bone disorder hormone/marker (fibroblast growth factor-23). Furthermore, it discusses their potential roles especially in ESRD and in future diagnostic and therapeutic strategies for CVD in the context of managing cardiorenal syndrome.

Cardiac troponin in patients hospitalized with acute decompensated heart failure: A systematic review and meta-analysis

BACKGROUND

Elevated cardiac troponin (cTn) is often observed in patients with acute decompensated heart failure (ADHF). We assessed the magnitude of association and quality of supporting evidence between cTn and clinically important outcomes in persons hospitalized for ADHF.

METHODS

We searched MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus from inception through February 28, 2015. The outcomes analyzed included hospital length of stay (LOS), readmissions, and mortality. Random effects meta-analysis was used to combine outcomes across studies.

RESULTS

We included 26 clinical studies. A detectable or elevated cTn was associated with increased LOS (odds ratio [OR]: 1.05; 95% confidence interval [CI]: 1.01-1.10), increased in-hospital mortality (OR: 2.57; 95% CI: 2.27-2.91), and a composite of mortality and major adverse events (OR: 1.33; 95% CI: 1.03-1.71) during hospitalization. ADHF patients with a detectable or elevated cTn were at increased risk for mortality and composite of mortality and readmission over the short term (mortality OR: 2.11; 95% CI: 1.43-3.12; composite OR: 2.81; 95% CI: 1.60-4.92), intermediate term (mortality OR: 2.21; 95% CI: 1.46-3.35; composite OR: 2.30; 95% CI: 1.78-2.99), and long term (mortality OR: 3.69; 95% CI: 2.64-5.18; composite OR: 3.49; 95% CI: 2.08-5.84). The overall confidence in estimates was moderate.

CONCLUSIONS

Among ADHF patients, a detectable or elevated cTn identifies subjects at increased risk for adverse clinical outcomes during acute hospitalization and those at higher risk for postdischarge mortality and composite of readmission and mortality. Journal of Hospital Medicine 2016;11:446-454. 2016 Society of Hospital Medicine.

Doxorubicin-induced cardiac dysfunction in unselected patients with a history of early-stage breast cancer

Cardiomyopathy is a known complication of anthracycline-based adjuvant chemotherapy and is more commonly reported in population-based studies of breast cancer survivors than in clinical trials. This study prospectively evaluated the prevalence of elevated cardiac biomarkers in unselected patients who had been treated with doxorubicin for early-stage breast cancer and the prevalence of reduced LVEF in patients with an elevated biomarker. All participants underwent an examination, symptom inventory, medical record review, and biomarker analysis for BNP, troponin, and plasma and urine NT-proBNP. Patients who had one or more elevated biomarkers were referred for echocardiogram; systolic dysfunction was defined as LVEF less than 55 %. Multivariable logistic regression was used to determine the associations between age, BMI, cumulative dose of doxorubicin, diabetes, hypertension, and left-sided radiation therapy and the risk of reduced LVEF. Among the 269 patients who underwent lab testing (mean age 56 years, mean time since completion of doxorubicin-based chemotherapy 6 years), 192 (72 %) had one or more elevated biomarker. Among the 166 patients who completed an echocardiogram, 11.5 % had a LVEF < 55 %. After adjusting for covariates known to affect cardiac function, multivariable logistic regression revealed plasma NT-proBNP to be the only measured cardiac biomarker associated with systolic dysfunction. There is a relationship between NT-proBNP and the frequency of reduced LVEF in women treated with doxorubicin for curative intent; further study of NT-proBNP as a potential biomarker for subclinical cardiac dysfunction after exposure to anthracyclines is warranted.

Biomarkers in cardiology--part 1--in heart failure and specific cardiomyopathies

Cardiovascular diseases are the leading causes of mortality and morbidity in Brazil. The primary and secondary preventions of those diseases are a priority for the health system and require multiple approaches to increase their effectiveness. Biomarkers are tools used to more accurately identify high-risk individuals, to speed the diagnosis, and to aid in treatment and prognosis determination. This review aims to highlight the importance of biomarkers in clinical cardiology practice, and to raise relevant points of their use and the promises for the coming years. This document was divided into two parts, and this first one discusses the use of biomarkers in specific cardiomyopathies and heart failure.

Old and newer biomarkers in heart failure: from pathophysiology to clinical significance

Heart failure is a complex disease in which a careful clinical examination and the measurement of cardiac function may not always be sufficient for making a correct diagnosis. Measuring plasma levels of natriuretic peptides may assist in this process, also offering a good tool for accurate risk stratification. Other alternative biomarkers may give insight into the different pathways of heart failure genesis and pathophysiology, and may help to identify those patients with overt heart failure and a more adverse outcome, or distinguish between those at risk of developing heart failure. Despite a high number of potentially useful biomarkers, only a few will likely be introduced routinely into clinical practice. However, a multi-marker approach might increase the diagnostic accuracy and it might identify different phenotypes of heart failure patients who might benefit from individualized therapy in the future.

The use of biomarkers in the patient with heart failure

Heart failure is a major burden to the health care system in terms of not only cost, but also morbidity and mortality. Appropriate use of biomarkers is critically important to allow rapid identification and optimal risk stratification and management of patients with both acute and chronic heart failure. This review will discuss the biomarkers that have the most diagnostic, prognostic, and therapeutic value in patients with heart failure. We will discuss established biomarkers such as natriuretic peptides as well as emerging biomarkers reflective of myocyte stress, myocyte injury, extracellular matrix injury, and both neurohormonal and cardio-renal physiology.

Defining High-Sensitivity Cardiac Troponin Concentrations in the Community

BACKGROUND

High-sensitivity cardiac troponin (hs-cTn) assays are now available that can detect measurable troponin in significantly more individuals in the general population than conventional assays. The clinical use of these hs-cTn assays depends on the development of proper reference values. Therefore, our objective was to define hs-cTnI reference values and determinants in the general community, in a healthy reference cohort, and in subsets with diseases.

MATERIALS AND METHODS

A well-characterized community-based cohort of 2042 study participants underwent clinical assessment and echocardiographic evaluation. Baseline hs-cTnI measurements were obtained in 1843 individuals. A healthy reference cohort (n = 565) without cardiac, renal, or echocardiographic abnormalities was identified.

RESULTS

Measurable hs-cTnI was identified in 1716 (93%) of the community-based study cohort and 499 (88%) of the healthy reference cohort. Parameters that significantly contributed to higher hs-cTnI concentrations in the healthy reference cohort included age, male sex, systolic blood pressure, and left ventricular mass. Glomerular filtration rate and body mass index were not independently associated with hs-cTnI in the healthy reference cohort. Individuals with diastolic and systolic dysfunction, hypertension, and coronary artery disease (but not impaired renal function) had significantly higher hs-cTnI values than the healthy reference cohort.

CONCLUSIONS

We assessed an hs-cTnI assay with the aid of echocardiographic imaging in a large, well-characterized community-based cohort. hs-cTnI is remarkably sensitive in the general population, and there are important sex and age differences among healthy reference individuals. These results have important implications for defining hs-cTnI reference values and identifying disease.

Cardiac troponin and heart failure in the era of high-sensitivity assays

The Joint European Society of Cardiology-American College of Cardiology Foundation-American Heart Association-World Heart Federation Task Force for the Redefinition of Myocardial Infarction recommends cardiac troponin (cTn)-T as a first-line biomarker, and suggests the use of the 99th percentile of a reference population with acceptable precision (i.e. a coefficient of variance≤10%) as a cut-off for the diagnosis of acute myocardial infarction. Recently developed troponin assays fulfill this analytical precision. While conventional cTnT assays have often been used as a positive or negative categorical variable, stepwise rises in high sensitivity (Hs)-cTnT in patients presenting with chronic heart failure (HF) have been associated with a progressive increase in the incidence of cardiovascular events. Similar observations have been made in the general population. Hs-cTnT at baseline and during follow-up is a powerful predictor of cardiac events in patients with HF and in the general population. Whether it is the ideal biomarker remains to be confirmed, however. We review the potential contributions of TnT assays in the assessment of risk of HF, in HF, and in myocardial diseases that cause HF.

Cardiovascular biomarkers and their utility in the older adult

Cardiovascular disease is the leading cause of morbidity and mortality in individuals over the age of 65 yet diagnosis, risk stratification and management continue to be more challenging than in younger adults due to the vast heterogeneity seen in this population. The current literature validates the use of biomarkers in addition to traditional risk assessment tools in younger and middle aged adults. The evidence for biomarkers in this older population is sparse; this review examines the epidemiological association of current biomarkers in the field and the utility of these markers in the diagnosis, risk discrimination and management of cardiovascular disease.

Troponin elevation in patients with heart failure: on behalf of the third Universal Definition of Myocardial Infarction Global Task Force: Heart Failure Section

Cardiac troponin testing is commonly performed in patients with heart failure (HF). Despite being strongly linked to spontaneous (Type I) acute myocardial infarction (MI)--a common cause of acute HF syndromes--it is well recognized that concentrations of circulating troponins above the 99 th percentile of a normal population in the context of both acute and chronic HF are highly prevalent, and frequently unrelated to Type I MI. Other mechanism(s) leading to troponin elevation in HF syndromes remain elusive in many cases but prominently includes supply-demand inequity (Type II MI), which may be associated with coronary artery obstruction and endothelial dysfunction, or may occur in the absence of coronary obstruction due to increased oxygen demand related to increased wall tension, anaemia, or other factors provoking subendocardial injury. Non-coronary triggers, such as cellular necrosis, apoptosis, or autophagy in the context of wall stress may explain the troponin release in HF, as can toxic effects of circulating neurohormones, toxins, inflammation, and infiltrative processes, among others. Nonetheless, across a wide spectrum of HF syndromes, when troponin elevation occurs, independent of mechanism, it is strongly predictive of an adverse outcome. Clinicians should be aware of the high frequency of troponin elevation when measuring the marker in patients with HF, should keep in mind the possible causes of this phenomenon, and, independent of a diagnosis of 'acute MI', should recognize the considerable ramifications of troponin elevation in this setting.

Biomarkers: optimizing treatment guidance in heart failure

Heart failure is a frequent and life-threatening syndrome which is not only the result of myocardial injury or hemodynamic overload as commonly perceived, but appears to be the result of an interplay among genetic, neurohormonal, inflammatory, and biochemical factors, collectively referred to as biomarkers. Biomarkers can become risk factors in case their therapeutic modification results in an improvement of clinical outcomes. Among those markers identified in patients with heart failure, a number appears to have direct clinical relevance in aiding diagnosis, risk stratification, monitoring therapy, and treating to targets in order to improve clinical outcomes. These include brain natriuretic peptides (e.g., BNP, NT-proBNP), inflammatory markers (e.g., hsCRP), neurohormones (e.g., aldosterone), cardiorenal markers (e.g., cycstatin C), and novel markers (e.g., galectin-3). While their utility to indicate risk is mostly well established, there are less data to establish that a treatment using biomarkers as a guidance results in better outcomes than a more generalized intensified treatment of patients with heart failure. Future directions may involve larger platforms that facilitate to simultaneously analyze hundreds of biomarkers and may help to tailor heart failure therapy on a single patient basis, considering the specific pathogenesis and prognosis. Also from a therapeutic perspective there are data that a single intervention such as aldosterone blockade may affect multiple biomarkers at the same time. Taken together the data indicate that biomarkers are evolving into a valuable addendum to the diagnostic and therapeutic armamentarium.

High sensitive troponin T and heart fatty acid binding protein: novel biomarker in heart failure with normal ejection fraction? A cross-sectional study

BACKGROUND

High sensitive troponin T (hsTnT) and heart fatty acid binding protein (hFABP) are both markers of myocardial injury and predict adverse outcome in patients with systolic heart failure (SHF). We tested whether hsTnT and hFABP plasma levels are elevated in patients with heart failure with normal ejection fraction (HFnEF).

METHODS

We analyzed hsTnT, hFABP and N-terminal brain natriuretic peptide in 130 patients comprising 49 HFnEF patients, 51 patients with asymptomatic left ventricular diastolic dysfunction (LVDD), and 30 controls with normal diastolic function. Patients were classified to have HFnEF when the diagnostic criteria as recommended by the European Society of Cardiology were met.

RESULTS

Levels of hs TnT and hFABP were significantly higher in patients with asymptomatic LVDD and HFnEF (both p < 0.001) compared to controls. The hsTnT levels were 5.6 [0.0-9.8] pg/ml in LVDD vs. 8.5 [3.9-17.5] pg/ml in HFnEF vs. <0.03 [< 0.03-6.4] pg/ml in controls; hFABP levels were 3029 [2533-3761] pg/ml in LVDD vs. 3669 [2918-4839] pg/ml in HFnEF vs. 2361 [1860-3081] pg/ml in controls. Furthermore, hsTnT and hFABP levels were higher in subjects with HFnEF compared to LVDD (p = 0.015 and p = 0.022).

CONCLUSION

In HFnEF patients, hsTnT and hFABP are elevated independent of coronary artery disease, suggesting that ongoing myocardial damage plays a critical role in the pathophysiology. A combination of biomarkers and echocardiographic parameters might improve diagnostic accuracy and risk stratification of patients with HFnEF.

Sensitive cardiac troponin T assay and the risk of incident cardiovascular disease in women with and without diabetes mellitus: the Women's Health Study

BACKGROUND

Very low levels of cardiac troponin T are associated with an increased risk of cardiovascular death in patients with stable chronic coronary disease. Whether high-sensitivity cardiac troponin T levels are associated with adverse cardiovascular outcomes in individuals without cardiovascular disease (CVD) has not been well studied.

METHODS AND RESULTS

Using 2 complementary study designs, we evaluated the relationship between baseline cardiac troponin and incident CVD events among diabetic and nondiabetic participants in the Women's Health Study (median follow-up, 12.3 years). All diabetic women with blood specimens were included in a cohort study (n=512 diabetic women, n=65 events), and nondiabetic women were sampled for inclusion in a case-cohort analysis (n=564 comprising the subcohort, n=479 events). High-sensitivity cardiac troponin T was detectable (≥ 0.003 μg/L) in 45.5% of diabetic women and 30.3% of nondiabetic women (P<0.0001). In models adjusted for traditional risk factors and hemoglobin A(1c), detectable high-sensitivity cardiac troponin T was associated with subsequent CVD (myocardial infarction, stroke, cardiovascular death) in diabetic women (adjusted hazard ratio, 1.79; 95% confidence interval, 1.04 to 3.07, P=0.036) but not nondiabetic women (adjusted hazard ratio, 1.13; 95% confidence interval, 0.82 to 1.55; P=0.46). Further adjustment for amino-terminal pro-B-type natriuretic peptide and estimated renal function did not substantially alter this relationship among diabetic women (hazard ratio, 1.76; 95% confidence interval, 1.00 to 3.08; P=0.0499), which appeared to be driven by a 3-fold increase in CVD death that was not observed in nondiabetic women.

CONCLUSIONS

Very low but detectable levels of cardiac troponin T are associated with total CVD and CVD death in women with diabetes mellitus. Among healthy nondiabetic women, detectable compared with undetectable troponin was not associated with CVD events.

Cation dyshomeostasis and cardiomyocyte necrosis: the Fleckenstein hypothesis revisited

An ongoing loss of cardiomyocytes to apoptotic and necrotic cell death pathways contributes to the progressive nature of heart failure. The pathophysiological origins of necrotic cell loss relate to the neurohormonal activation that accompanies acute and chronic stressor states and which includes effector hormones of the adrenergic nervous system. Fifty years ago, Albrecht Fleckenstein and coworkers hypothesized the hyperadrenergic state, which accompanies such stressors, causes cardiomyocyte necrosis based on catecholamine-initiated excessive intracellular Ca(2+) accumulation (EICA), and mitochondrial Ca(2+) overloading in particular, in which the ensuing dysfunction and structural degeneration of these organelles leads to necrosis. In recent years, two downstream factors have been identified which, together with EICA, constitute a signal-transducer-effector pathway: (i) mitochondria-based induction of oxidative stress, in which the rate of reactive oxygen metabolite generation exceeds their rate of detoxification by endogenous antioxidant defences; and (ii) the opening of the mitochondrial inner membrane permeability transition pore (mPTP) followed by organellar swelling and degeneration. The pathogenesis of stress-related cardiomyopathy syndromes is likely related to this pathway. Other factors which can account for cytotoxicity in stressor states include: hypokalaemia; ionized hypocalcaemia and hypomagnesaemia with resultant elevations in parathyroid hormone serving as a potent mediator of EICA; and hypozincaemia with hyposelenaemia, which compromise antioxidant defences. Herein, we revisit the Fleckenstein hypothesis of EICA in leading to cardiomyocyte necrosis and the central role played by mitochondria.

Association of serial measures of cardiac troponin T using a sensitive assay with incident heart failure and cardiovascular mortality in older adults

CONTEXT

Older adults comprise the majority of new-onset heart failure (HF) diagnoses, but traditional risk-factor prediction models have limited accuracy in this population to identify those at highest risk for hospitalization or death.

OBJECTIVES

To determine if cardiac troponin T (cTnT) measured by a highly sensitive assay would be detectable in the majority of community-dwelling older adults, and if serial measures were associated with risk of HF hospitalization and cardiovascular death.

DESIGN, SETTING, AND PARTICIPANTS

A longitudinal nationwide cohort study (Cardiovascular Health Study) of 4221 community-dwelling adults aged 65 years or older without prior HF who had cTnT measured using a highly sensitive assay at baseline (1989-1990) and repeated after 2 to 3 years (n = 2918).

MAIN OUTCOME MEASURES

New-onset HF and cardiovascular death were examined through June 2008 with respect to cTnT concentrations, accounting for clinical risk predictors.

RESULTS

Cardiac troponin T was detectable (≥3.00 pg/mL) in 2794 participants (66.2%). During a median follow-up of 11.8 years, 1279 participants experienced new-onset HF and 1103 cardiovascular deaths occurred, with a greater risk of both end points associated with higher cTnT concentrations. Among those participants with the highest cTnT concentrations (>12.94 pg/mL), there was an incidence rate per 100 person-years of 6.4 (95% confidence interval [CI], 5.8-7.2; adjusted hazard ratio [aHR], 2.48; 95% CI, 2.04-3.00) for HF and an incidence rate of 4.8 (95% CI, 4.3-5.4; aHR, 2.91; 95% CI, 2.37-3.58) for cardiovascular death compared with participants with undetectable cTnT levels (incidence rate, 1.6; 95% CI, 1.4-1.8 and 1.1; 95% CI, 0.9-1.2 for HF and cardiovascular death, respectively). Among individuals with initially detectable cTnT, a subsequent increase of more than 50% (n = 393, 22%) was associated with a greater risk for HF (aHR, 1.61; 95% CI, 1.32-1.97) and cardiovascular death (aHR, 1.65; 95% CI, 1.35-2.03) and a decrease of more than 50% (n = 247, 14%) was associated with a lower risk for HF (aHR, 0.73; 95% CI, 0.54-0.97) and cardiovascular death (aHR, 0.71; 95% CI, 0.52-0.97) compared with participants with 50% or less change. Addition of baseline cTnT measurements to clinical risk factors was associated with only modest improvement in discrimination, with change in C statistic of 0.015 for HF and 0.013 for cardiovascular death.

CONCLUSION

In this cohort of older adults without known HF, baseline cTnT levels and changes in cTnT levels measured with a highly sensitive assay were significantly associated with incident HF and cardiovascular death.

A window into your heart: taking cardiac troponin to the next level

The cardiac troponins are important cardiovascular biomarkers for myocardial necrosis and are measured in thousands of patients daily. In parallel with the widespread adoption of troponin testing for the diagnosis of myocardial infarction during the last two decades, the analytical sensitivity of assays has progressively improved, which has allowed the identification of more acute coronary syndrome patients at risk of future cardiac events. In addition, using novel high-sensitivity assays, circulating troponin can be observed not only in acute settings, but also in many patients suffering from chronic diseases such as coronary artery disease, heart failure and diabetes. We believe that these findings provide a compelling case for exploring whether troponin levels may be a useful tool for guiding clinical decision-making directly in the management of some of these chronic conditions. Sampling of troponin in such patient populations may allow for more refined risk stratification and, importantly, help clinicians individualize care beyond what is currently possible.

Prognostic Assessment of Elderly Patients with Symptoms of Heart Failure by Combining High-Sensitivity Troponin T and N-Terminal Pro–B-Type Natriuretic Peptide Measurements

BACKGROUND

N-terminal pro–B-type natriuretic peptide (NT-proBNP) is a useful biomarker in heart failure assessment, whereas measurement of cardiac troponin is central in the diagnosis of patients with acute coronary syndromes. This report examined the prognostic use of combining high-sensitivity cardiac troponin T (hs-cTnT) and NT-proBNP measurements in elderly patients presenting to a primary care center with symptoms associated with heart failure.

METHODS

A total of 470 elderly patients (age range 65–86 years) presenting with symptoms of heart failure were recruited from primary healthcare. In addition to clinical examination and echocardiography, hs-cTnT and NT-proBNP plasma concentrations were measured. All patients were followed for 10 years, and cardiovascular mortality was registered.

RESULTS

By use of the hs-cTnT assay, 80.4% of the population had plasma concentrations above the lower detection limit of the assay. Of those displaying a plasma concentration of hs-cTnT &gt;99th percentile of a healthy population, 43% also had an NT-proBNP concentration in the fourth quartile (&gt;507 ng/L). In the multivariate analysis, we observed a 2.5-fold increased risk for cardiovascular mortality in individuals with a plasma NT-proBNP concentration &gt;507 ng/L (P &lt; 0.0001). Conversely, patients with hs-cTnT &gt;99th percentile displayed an approximately 2-fold increased risk for cardiovascular mortality (P = 0.0002). Combining the 2 biomarkers, NT-proBNP concentrations &gt;507 ng/L with hs-cTnT &gt;99th percentile increased the risk 3-fold, even after adjustment for clinical variables such as age, sex, impaired estimated glomerular filtration rate, and anemia (P &lt; 0.0001).

CONCLUSIONS

hs-cTnT and NT-proBNP measurements combined provide better prognostic information than using either biomarker separately in elderly patients with symptoms associated with heart failure.

Troponin elevation in heart failure prevalence, mechanisms, and clinical implications

Circulating biomarkers have become increasingly important in diagnosing and risk stratifying patients with heart failure (HF). While the natriuretic peptides have received much focus, there is increasing interest in the role of circulating cardiac troponin (cTn) in detecting myocardial injury (often subclinical) in those with HF. Accumulating evidence suggests that patients with chronic and acute HF may have measurable levels of circulating cTn, whose detection and magnitude may have prognostic implications. Furthermore, as new, more sensitive cTn assays are being developed, larger numbers of HF patients are found to have detectable cTn with a persistent relationship between magnitude and outcome. This knowledge improves our ability to understand the mechanism of worsening HF, improve risk stratification, and detect potential injury related to new therapeutics in HF. As investigators begin to understand the relationship of detectable cTn to HF outcomes, as well as temporal changes in its magnitude, and its relationship to other circulating biomarkers, more insight may be gained into the progressive nature of cardiac dysfunction and the transition from chronic compensated to acute decompensated HF. Ultimately, this information might allow physicians to guide therapy, choose appropriate therapeutics, and improve HF outcomes.

An update on cardiac troponins as circulating biomarkers in heart failure

Circulating troponins and natriuretic peptides are the only biomarkers specifically released from cardiac myocytes that can be determined with robust and sensitive analytical methods, even in healthy subjects. These intracellular proteins are released from reversibly or irreversibly damaged cardiac myocytes into the bloodstream by mechanisms that are not entirely clear. The recent introduction of a new generation of highly sensitive assays of cardiac troponin I or T has not only improved the early diagnosis of acute myocardial infarction but also suggested that there are several causes for troponin release other than acute coronary syndromes. Circulating troponins are elevated in patients with acute or chronic heart failure and are strongly associated with outcome, independently of natriuretic peptides, the benchmark biomarkers in heart failure. In the absence of further experimental evidences, the pathophysiologic basis for the elevation of circulating cardiac troponins in patients with stable chronic heart failure remains speculative.

High-sensitivity troponin T concentrations in acute chest pain patients evaluated with cardiac computed tomography

BACKGROUND

For evaluation of patients with chest pain and suspected acute coronary syndrome (ACS), consensus guidelines recommend use of a cardiac troponin cut point that corresponds to the 99 th percentile of a healthy population. Most conventional troponin methods lack sufficient precision at this low level.

METHODS AND RESULTS

In a cross-sectional study, 377 patients (mean age 53.7 years, 64.2% male) with chest pain and low to intermediate likelihood for ACS were enrolled in the emergency department. Blood was tested with a precommercial high-sensitivity troponin T assay (hsTnT) and compared with a conventional cardiac troponin T method. Patients underwent a 64-slice coronary computed tomography coronary angiogram at the time of phlebotomy, on average 4 hours from initial presentation. Among patients with acute chest pain, 37 (9.8%) had an ACS. Using the 99th percentile cut point for a healthy population (13 pg/mL), hsTnT had 62% sensitivity, 89% specificity, 38% positive predictive value, and 96% negative predictive value for ACS. Compared with the cardiac troponin T method, hsTnT detected 27% more ACS cases (P=.001), and an hsTnT above the 99 th percentile strongly predicted ACS (odds ratio 9.0, 95% confidence interval 3.9 to 20.9, P<0.001). Independent of ACS diagnosis, computed tomography angiography demonstrated that concentrations of hsTnT were determined by numerous factors, including the presence and severity of coronary artery disease, left ventricular mass, left ventricular ejection fraction, and regional left ventricular dysfunction.

CONCLUSIONS

Among low- to intermediate-risk patients with chest pain, hsTnT provides good sensitivity and specificity for ACS. Elevation of hsTnT identifies patients with myocardial injury and significant structural heart disease, irrespective of the diagnosis of ACS.

Chronic heart failure: contemporary diagnosis and management

Chronic heart failure (CHF) remains the only cardiovascular disease with an increasing hospitalization burden and an ongoing drain on health care expenditures. The prevalence of CHF increases with advancing life span, with diastolic heart failure predominating in the elderly population. Primary prevention of coronary artery disease and risk factor management via aggressive blood pressure control are central in preventing new occurrences of left ventricular dysfunction. Optimal therapy for CHF involves identification and correction of potentially reversible precipitants, target-dose titration of medical therapy, and management of hospitalizations for decompensation. The etiological phenotype, absolute decrease in left ventricular ejection fraction and a widening of QRS duration on electrocardiography, is commonly used to identify patients at increased risk of progression of heart failure and sudden death who may benefit from prophylactic implantable cardioverter-defibrillator placement with or without cardiac resynchronization therapy. Patients who transition to advanced stages of disease despite optimal traditional medical and device therapy may be candidates for hemodynamically directed approaches such as a left ventricular assist device; in selected cases, listing for cardiac transplant may be warranted.