Role of troponin in patients with chronic kidney disease and suspected acute coronary syndrome: a systematic review

Hemodialysis and biomarkers of myocardial infarction - a cohort study

OBJECTIVES

End-stage renal disease is associated with a high risk of cardiovascular disease. We compared the concentration and prognostic ability of high sensitivity cardiac troponin T (hs-cTnT) and I (hs-cTnI) and cardiac myosin-binding protein C (cMyC) among stable hemodialysis patients.

METHODS

Patients were sampled before and after hemodialysis. We measured hs-cTnI, hs-cTnT and cMyC and used Cox regressions to assess the association between quartiles of concentrations and all-cause mortality and a combination of cardiovascular events and all-cause mortality during follow-up.

RESULTS

A total of 307 patients were included, 204 males, mean age 66 years (SD 14). Before dialysis, 299 (99 %) had a hs-cTnT concentration above the 99th percentile, compared to 188 (66 %) for cMyC and 35 (11 %) for hs-cTnI. Hs-cTnT (23 %, p<0.001) and hs-cTnI (15 %, p=0.049) but not cMyC (4 %, p=0.256) decreased during dialysis. Follow-up was a median of 924 days (492-957 days); patients in the 3rd and 4th quartiles of hs-cTnT (3rd:HR 3.0, 95 % CI 1.5-5.8, 4th:5.2, 2.7-9.8) and the 4th quartile of hs-cTnI (HR 3.8, 2.2-6.8) had an increased risk of mortality. Both were associated with an increased risk of the combined endpoint for patients in the 3rd and 4th quartiles. cMyC concentrations were not associated with risk of mortality or cardiovascular event.

CONCLUSIONS

Hs-cTnT was above the 99th percentile in almost all patients. This was less frequent for hs-cTnI and cMyC. High cTn levels were associated with a 3-5-fold higher mortality. This association was not present for cMyC. These findings are important for management of hemodialysis patients.

Utility of Cardiac Troponins in Patients With Chronic Kidney Disease

Cardiovascular disease is a major cause of death worldwide especially in patients with chronic kidney disease (CKD). Troponin T and troponin I are cardiac biomarkers used not only to diagnose acute myocardial infarction (AMI) but also to prognosticate cardiovascular and all-cause mortality. The diagnosis of AMI in the CKD population is challenging because of their elevated troponins at baseline. The development of high-sensitivity cardiac troponins shortens the time needed to rule in and rule out AMI in patients with normal renal function. While the sensitivity of high-sensitivity cardiac troponins is preserved in the CKD population, the specificity of these tests is compromised. Hence, diagnosing AMI in CKD remains problematic even with the introduction of high-sensitivity assays. The prognostic significance of troponins did not differ whether it is detected with standard or high-sensitivity assays. The elevation of both troponin T and troponin I in CKD patients remains strongly correlated with adverse cardiovascular and all-cause mortality, and the prognosis becomes poorer with advanced CKD stages. Interestingly, the degree of troponin elevation appears to be predictive of the rate of renal decline via unclear mechanisms though activation of the renin-angiotensin and other hormonal/oxidative stress systems remain suspect. In this review, we present the latest evidence of the use of cardiac troponins in both the diagnosis of AMI and the prognosis of cardiovascular and all-cause mortality. We also suggest strategies to improve on the diagnostic capability of these troponins in the CKD/end-stage kidney disease population.

A risk model for the early diagnosis of acute myocardial infarction in patients with chronic kidney disease

Introduction

Acute myocardial infarction (AMI) remains a critical disease, characterized by a high fatality rate in several countries. In clinical practice, the incidence of AMI is increased in patients with chronic kidney disease (CKD). However, the early diagnosis of AMI in the above group of patients is still poor.

Methods

In the present study, a total of 829 patients with CKD, defined by an estimated glomerular filtration rate (eGFR) of <60 ml/min/1.73 m2 or 60-90 ml/min/1.73 m2 for patients with mildly reduced kidney function, who attended the Sichuan Provincial People's Hospital (SPPH) between January 2018 and November 2022 were enrolled. All patients underwent coronary angiography due to the presence of typical or atypical symptoms of AMI. Patients were divided into the following two groups: The training cohort, including 255 participants with AMI and 242 without AMI; and the testing cohort, including 165 and 167 subjects with and without AMI, respectively. Furthermore, a forward stepwise regression model and a multivariable logistic regression model, named SPPH-AMI-model, were constructed to select significant predictors and assist the diagnosis of AMI in patients with CKD, respectively.

Results

The following factors were evaluated in the model: Smoking status, high sensitivity cardiac troponin I, serum creatinine and uric acid levels, history of percutaneous coronary intervention and electrocardiogram. Additionally, the area under the curve (AUC) of the receiver operating characteristic curve were determined in the risk model in the training set [AUC, 0.78; 95% confidence interval (CI), 0.74-0.82] vs. the testing set (AUC, 0.74; 95% CI, 0.69-0.79) vs. the combined set (AUC, 0.76; 95% CI, 0.73-0.80). Finally, the sensitivity and specificity rates were 71.12 and 71.21%, respectively, the percentage of cases correctly classified was 71.14%, while positive and negative predictive values of 71.63 and 70.70%, respectively, were also recorded.

Discussion

The results of the current study suggested that the SPPH-AMI-model could be currently considered as the only risk scoring system for the early diagnosis of AMI in patients with CKD. This method could help clinicians and emergency physicians to quickly and accurately diagnose AMI in patients with CKD to promote the immediate and effective treatment of these patients.

Role of Cardiac Troponins in Predicting Adverse Outcomes in Acute Coronary Syndrome With Renal Dysfunction

A substantial global cause of mortality as well as disability is acute myocardial infarction (AMI). It is also widespread knowledge that patients with chronic kidney disease (CKD) possess greater mortality and cardiovascular disease risks than the rest of the population. A vital biomarker for the diagnosis of AMI is high-sensitive cardiac troponin T (hs-cTnT). Individuals afflicted with severe CKD frequently exhibit increased hs-cTnT levels, which can pose a significant diagnostic challenge in cases of non-ST elevation acute coronary syndrome (NSTE-ACS) necessitating revascularization. Alteration in kidney function exerts an impact on troponin levels, making a single value less useful. As the renal population has an increased risk of non-ST-segment elevation myocardial infarction (NSTEMI), serial tracking of cardiac biomarkers is essential to detect ACS in this population. Numerous studies using algorithmic remedies based on admission troponin and spontaneous variations in troponin concentration have been put forth by researchers to address these issues. A considerable majority of CKD patients can be accurately diagnosed or excluded from having AMI using the approach, which involves serial measures. Patients who suffer from kidney impairment exhibit lesser chances of undergoing angiography or revascularization and receiving preventative therapies. Furthermore, their outcomes are comparatively poorer when compared to patients who possess normal kidney function. Despite studies indicating a higher risk of poor outcomes after AMI in this population, these patients are less likely to receive guideline-indicated care. In this study, we employed a systematic literature review (SLR) methodology to provide an account of the available studies and to draw attention to the importance of cardiac troponins in predicting unfavorable outcomes and algorithms in the prediction, diagnosis, and prognosis of patients with ACS and renal impairment. Eight papers were chosen for in-depth analysis after reviewing 86 articles from trusted publications between 2013 and August 3, 2023. The analysis considered factors such as sensitivity, severity of renal damage, algorithms used, the benefits of algorithms, and the challenges. One must examine the change in cardiac troponin (cTn) and take higher cut-off values into consideration in order to increase the sensitivity and specificity for the diagnosis of AMI. Higher levels of cTn have also been correlated prognostically to unfavorable outcomes like incident heart failure and death from cardiovascular causes. Also, raised troponin levels have been linked to all-cause and cardiovascular death in both dialysis patients and patients with CKD who did not receive dialysis. Future studies should concentrate on whether troponin testing can reclassify risk and provide treatment in people with CKD who are at the greatest threat of death. The clinical practice benefits of routinely measuring cardiac troponin concentrations are largely unknown. Future research should also concentrate on figuring out how troponin testing can influence clinical management and how to address the root reasons for chronic hs-cTnT elevation in patients with CKD, which may include elements like uremic toxicity, macrovascular or microvascular ischemia, anemia, as well as reduced renal clearance.

Pathophysiological concepts and screening of cardiovascular disease in dialysis patients

Dialysis patients experience 10-20 times higher cardiovascular mortality than the general population. The high burden of both conventional and nontraditional risk factors attributable to loss of renal function can explain higher rates of cardiovascular disease (CVD) morbidity and death among dialysis patients. As renal function declines, uremic toxins accumulate in the blood and disrupt cell function, causing cardiovascular damage. Hemodialysis patients have many cardiovascular complications, including sudden cardiac death. Peritoneal dialysis puts dialysis patients with end-stage renal disease at increased risk of CVD complications and emergency hospitalization. The current standard of care in this population is based on observational data, which has a high potential for bias due to the paucity of dedicated randomized clinical trials. Furthermore, guidelines lack specific guidelines for these patients, often inferring them from non-dialysis patient trials. A crucial step in the prevention and treatment of CVD would be to gain better knowledge of the influence of these predisposing risk factors. This review highlights the current evidence regarding the influence of advanced chronic disease on the cardiovascular system in patients undergoing renal dialysis.

High-Sensitivity Troponins and Subclinical Coronary Atherosclerosis Evaluated by Coronary Calcium Score Among Older Asians Living With Well-Controlled Human Immunodeficiency Virus

Background

Elevated levels of high-sensitivity cardiac troponin (hs-cTn) are suggestive of myocardial cell injury and coronary artery disease. We explored the association between hs-cTn and subclinical arteriosclerosis using coronary artery calcification (CAC) scoring among 337 virally suppressed patients with human immunodeficiency virus (HIV) who were ≥50 years old and without evidence of known coronary artery disease.

Methods

Noncontrast cardiac computed tomography and blood sampling for hs-cTn, both subunit I (hs-cTnI) and subunit T (hs-cTnT), were performed. The relationship between CAC (Agatston score) and serum hs-cTn levels was analyzed using Spearman correlation and logistic regression models.

Results

The patients, of whom 62% were male, had a median age of 54 years and had been on antiretroviral therapy for a median of 16 years; the CAC score was >0 in 50% of patients and ≥100 in 16%. Both hs-cTn concentrations were positively correlated with the Agatston score, with correlation coefficients of 0.28 and 0.27 (P < .001) for hs-cTnI and hs-cTnT, respectively. hs-cTnI and hs-cTnT concentrations of ≥4 and ≥5.3 pg/mL, respectively, provided the best performance for discriminating patients with Agatston scores ≥100, with a sensitivity and specificity of 76% and 60%, respectively, for hs-cTnI and 70% and 50% for hs-cTnT. In multivariable logistic regression analysis, each log unit increase in hs-cTnI level was independently associated with increased odds of having an Agatston score ≥100 (odds ratio, 2.83 [95% confidence interval, 1.69-4.75]; P <.001). Although not an independent predictor, hs-cTnT was also associated with an increased odds of having an Agatston score ≥100 (odds ratio, 1.58 [95% confidence interval, .92-2.73]; P = .10).

Conclusions

Among Asians aged ≥50 years with well-controlled HIV infection and without established cardiovascular disease, 50% had subclinical arteriosclerosis. Increasing hs-cTnI and hs-cTnT concentrations were associated with an increased risk of severe subclinical arteriosclerosis, and hs-cTn may be a potential biomarker to detect severe subclinical arteriosclerosis.

Ethnicity and sex-specific 99th percentile upper reference limits of high-sensitivity cardiac troponin I among adults in Xinjiang, China

OBJECTIVES

To determine the 99th percentile upper reference limit (URL) of high-sensitivity cardiac troponin I (hs-cTnI) in a healthy population in Xinjiang, China, and investigate the impact of ethnicity, sex, and age on this limit.

DESIGN AND METHODS

From September 2018 to March 2022, 5,090 Han and Uyghur adults aged 20-79 years were recruited. After questionnaire screening, 2,970 participants with physical and/or laboratory normality were enrolled. Participants recruited between September 2018 and October 2021 (2,109/2,970) were evaluated by ARCHITECTi2000 to determine the 99th percentile URL of hs-cTnI. The results were then validated in 861/2,970 participants recruited from November 2021 to March 2022. A criterion of ≤10% of test results falling outside the original determined value was used to determine whether the newly established reference intervals were valid.

RESULTS

The hs-cTnI concentration was higher among Uyghurs than among Han participants (p<0.001). The 99th percentile URLs were 17.52 ng/L for all participants, 18.96 ng/L for Uyghur, and 16.93 ng/L for Han. Hs-cTnI concentration was also correlated with sex and age. In the Han and Uyghur groups, male participants had a higher hs-cTnI concentration than female participants (p<0.001); the 99th percentile URLs of hs-cTnI among male and female participants were 17.80 vs. 13.67 ng/L and 19.47 vs. 16.52 ng/L, respectively. Stratified by age, hs-cTnI concentrations were higher in participants aged >60 years than in those of other age categories (p<0.001), in both the Han and Uyghur groups. Finally, <2% of these test results exceeded the newly established reference, validating the results.

CONCLUSIONS

This study established the 99th percentile URLs of hs-cTnI in the Xinjiang. Ethnicity and sex influence the value and should be considered.

High-dose intravenous iron reduces myocardial infarction in patients on haemodialysis

AIMS

To investigate the effect of high-dose iron vs. low-dose intravenous (IV) iron on myocardial infarction (MI) in patients on maintenance haemodialysis.

METHODS AND RESULTS

This was a pre-specified analysis of secondary endpoints of the Proactive IV Iron Therapy in Hemodialysis Patients trial (PIVOTAL) randomized, controlled clinical trial. Adults who had started haemodialysis within the previous year, who had a ferritin concentration <400 μg per litre and a transferrin saturation <30% were randomized to high-dose or low-dose IV iron. The main outcome measure for this analysis was fatal or non-fatal MI. Over a median of 2.1 years of follow-up, 8.4% experienced a MI. Rates of type 1 MIs (3.2/100 patient-years) were 2.5 times higher than type 2 MIs (1.3/100 patient-years). Non-ST-elevation MIs (3.3/100 patient-years) were 6 times more common than ST-elevation MIs (0.5/100 patient-years). Mortality was high after non-fatal MI (1- and 2-year mortality of 40% and 60%, respectively). In time-to-first event analyses, proactive high-dose IV iron reduced the composite endpoint of non-fatal and fatal MI [hazard ratio (HR) 0.69, 95% confidence interval (CI) 0.52-0.93, P = 0.01] and non-fatal MI (HR 0.69, 95% CI 0.51-0.93; P = 0.01) when compared with reactive low-dose IV iron. There was less effect of high-dose IV iron on recurrent MI events than on the time-to-first event analysis.

CONCLUSION

In total, 8.4% of patients on maintenance haemodialysis had an MI over 2 years. High-dose compared to low-dose IV iron reduced MI in patients receiving haemodialysis.

EUDRACT REGISTRATION NUMBER

2013-002267-25.

Applications of cardiac biomarkers in chronic kidney disease

PURPOSE OF REVIEW

Cardiovascular disease is the leading cause of death in individuals with chronic kidney disease (CKD). The mechanisms connecting CKD and cardiovascular disease are complex, and serum biomarkers can help improve our understanding. Nt-proBNP and troponin have documented success as biomarkers to diagnose and provide mechanistic insights in non-CKD populations. The purpose of this review is to summarize evidence suggesting efficacy and potential for clinical application of Nt-proBNP and troponin in individuals with CKD.

RECENT FINDINGS

Our understanding of how Nt-proBNP and Troponin should be interpreted in those with CKD is evolving. Although both biomarkers are in part cleared by the kidney, elevated levels predominantly reflect cardiovascular disease. Both Nt-proBNP and troponin are associated with risk for future cardiovascular events in CKD. Determining CKD-specific cutoffs and using biomarkers to guide therapy remains under active investigation.

SUMMARY

Of the many serum biomarkers under investigation, Nt-proBNP and troponin best meet the criteria for effective biomarkers in CKD. Assays are widely available and proven to be accurate in CKD populations. Nt-proBNP and troponin deserve special focus in ongoing research of cardiovascular risk reduction in CKD, especially to identify patients at the highest risk, suggest targetable mechanisms and assess treatment efficacy.

High-sensitivity cardiac troponin and the diagnosis of myocardial infarction in patients with kidney impairment

The benefit and utility of high-sensitivity cardiac troponin (hs-cTn) in the diagnosis of myocardial infarction in patients with kidney impairment is unclear. Here, we describe implementation of hs-cTnI testing on the diagnosis, management, and outcomes of myocardial infarction in patients with and without kidney impairment. Consecutive patients with suspected acute coronary syndrome enrolled in a stepped-wedge, cluster-randomized controlled trial were included in this pre-specified secondary analysis. Kidney impairment was defined as an eGFR under 60mL/min/1.73m2. The index diagnosis and primary outcome of type 1 and type 4b myocardial infarction or cardiovascular death at one year were compared in patients with and without kidney impairment following implementation of hs-cTnI assay with 99th centile sex-specific diagnostic thresholds. Serum creatinine concentrations were available in 46,927 patients (mean age 61 years; 47% women), of whom 9,080 (19%) had kidney impairment. hs-cTnIs were over 99th centile in 46% and 16% of patients with and without kidney impairment. Implementation increased the diagnosis of type 1 infarction from 12.4% to 17.8%, and from 7.5% to 9.4% in patients with and without kidney impairment (both significant). Patients with kidney impairment and type 1 myocardial infarction were less likely to undergo coronary revascularization (26% versus 53%) or receive dual anti-platelets (40% versus 68%) than those without kidney impairment, and this did not change post-implementation. In patients with hs-cTnI above the 99th centile, the primary outcome occurred twice as often in those with kidney impairment compared to those without (24% versus 12%, hazard ratio 1.53, 95% confidence interval 1.31 to 1.78). Thus, hs-cTnI testing increased the identification of myocardial injury and infarction but failed to address disparities in management and outcomes between those with and without kidney impairment.

High-Sensitivity Troponin: A Review on Characteristics, Assessment, and Clinical Implications

The use of high-sensitivity cardiac troponin (hs-cTn) assays has become part of the daily practice in most of the laboratories worldwide in the initial evaluation of the typical chest pain. Due to their early surge, the use of hs-cTn may reduce the time needed to recognise myocardial infarctions (MI), which is vital for the patients presenting in the emergency departments for chest pain. The latest European Society of Cardiology Guidelines did not only recognise their central role in the diagnosis algorithm but also recommended their use for rapid rule-in/rule-out of MI. High-sensitivity cardiac troponins are also powerful prognostic markers for long-term events and mortality, not only in a wide spectrum of other cardiovascular diseases (CVD) but also in several non-CVD pathologies. Moreover, these biomarkers became a powerful tool in special populations, such as paediatric patients and, most recently, COVID-19 patients. Although highly investigated, the assessment and interpretation of the hs-cTn changes are still challenging in the patients with basal elevation such as CKD or critically ill patients. Moreover, there are still various analytical characteristics not completely understood, such as circadian or sex variability, with major clinical implications. In this context, the present review focuses on summarizing the most recent research in the current use of hs-cTn, with a main consideration for its role in the diagnosis of MI but also its prognostic value. We have also carefully selected the most important studies regarding the challenges faced by clinicians from different specialties in the correct interpretation of this biomarker. Moreover, future perspectives have been proposed and analysed, as more research and cross-disciplinary collaboration are necessary to improve their performance.

Upper Reference Limits for High-Sensitivity Cardiac Troponin T and N-Terminal Fragment of the Prohormone Brain Natriuretic Peptide in Patients With CKD

RATIONALE & OBJECTIVE

The utility of conventional upper reference limits (URL) for N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hsTnT) in chronic kidney disease (CKD) remains debated. We analyzed the distribution of hsTnT and NT-proBNP in people with CKD in ambulatory settings to examine the diagnostic value of conventional URL in this population.

STUDY DESIGN

Observational study.

SETTING & PARTICIPANTS

We studied participants of the Chronic Renal Insufficiency Cohort (CRIC) with CKD and no self-reported history of cardiovascular disease.

EXPOSURE

Estimated glomerular filtration rate (eGFR).

OUTCOME

NT-proBNP and hsTnT at baseline.

ANALYTICAL APPROACH

We described the proportion of participants above the conventional URL for NT-proBNP (125pg/mL) and hsTnT (14ng/L) overall and by eGFR. We then estimated 99th percentile URL for NT-proBNP and hsTnT. Using quantile regression of the 99th percentile, we modeled the association of eGFR with NT-proBNP and hsTnT.

RESULTS

Among 2,312 CKD participants, 40% and 43% had levels of NT-proBNP and hsTnT above the conventional URL, respectively. In those with eGFR <30mL/min/1.73m², 71% and 68% of participants had concentrations of NT-proBNP and hsTnT above the conventional URL, respectively. Among all CKD participants, the 99th percentile for NT-proBNP was 3,592 (95% CI, 2,470-4,849) pg/mL and for hsTnT it was 126 (95% CI, 100-144) ng/L. Each 15mL/min/1.73m² decrement in eGFR was associated with a ~40% higher threshold for the 99th percentile of NT-proBNP (1.43 [95% CI, 1.21-1.69]) and hsTnT (1.45 [95% CI, 1.31-1.60]).

LIMITATIONS

Study included ambulatory patients, and we could not test the accuracy of the URL of NT-proBNP and hsTnT in the acute care setting.

CONCLUSIONS

In this ambulatory CKD population with no self-reported history of cardiovascular disease, a range of 40%-88% of participants had concentrations of NT-proBNP and hsTnT above the conventional URL, depending on eGFR strata. Developing eGFR-specific thresholds for these commonly used cardiac biomarkers in the setting of CKD may improve their utility for evaluation of suspected heart failure and myocardial infarction.

Advances in the Progression and Prognosis Biomarkers of Chronic Kidney Disease

Chronic kidney disease (CKD) is one of the increasingly serious public health concerns worldwide; the global burden of CKD is increasingly due to high morbidity and mortality. At present, there are three key problems in the clinical treatment and management of CKD. First, the current diagnostic indicators, such as proteinuria and serum creatinine, are greatly interfered by the physiological conditions of patients, and the changes in the indicator level are not synchronized with renal damage. Second, the established diagnosis of suspected CKD still depends on biopsy, which is not suitable for contraindication patients, is also traumatic, and is not sensitive to early progression. Finally, the prognosis of CKD is affected by many factors; hence, it is ineviatble to develop effective biomarkers to predict CKD prognosis and improve the prognosis through early intervention. Accurate progression monitoring and prognosis improvement of CKD are extremely significant for improving the clinical treatment and management of CKD and reducing the social burden. Therefore, biomarkers reported in recent years, which could play important roles in accurate progression monitoring and prognosis improvement of CKD, were concluded and highlighted in this review article that aims to provide a reference for both the construction of CKD precision therapy system and the pharmaceutical research and development.

The Ratio of NT-proBNP to CysC1.53 Predicts Heart Failure in Patients With Chronic Kidney Disease

Background: The N-terminal pro B type natriuretic peptide (NT-proBNP) is important for prognosis of heart failure in patients with chronic kidney disease (CKD). However, the NT-proBNP level is easily affected by renal insufficiency, which limits its clinical use. Methods: This study included 396 patients with CKD. Plasma levels of NT-proBNP and cystatin C (CysC) were measured during hospitalization. The echocardiographic parameters were also detected. Patients were divided into the heart failure group and control group according to the European Society of Cardiology Guideline on Chronic Heart Failure 2021. Multiple modeling analysis of the values of NT-proBNP and CysC, including NT-proBNP/Cyscn and NT-proBNP/nCysC was performed. The receiver operating characteristic (ROC) curve, combined with the cardiac function, was used to determine the formula with the best diagnostic efficiency. Then, the sensitivity and specificity of new predictors for cardiac insufficiency in CKD patients were calculated. Pearson correlation analysis was used to analyze the relationship between new predictors and the NT-proBNP level. The clinical data of CKD patients from another local hospital were used to validate the new predictors and the cut-off values. Results: An elevated NT-proBNP/CysC1.53 ratio was an independent risk factor for cardiac dysfunction in CKD and the best predictor derived from multiple modeling analysis. There was no correlation between the NT-proBNP/CysC1.53 ratio and the NT-proBNP level (r = 0.376, p = 6.909). The area under the ROC curve for the NT-proBNP/CysC1.53 ratio was 0.815 (95% confidence interval: 0.772-0.858), and for a cut-off point of 847.964, this ratio had a sensitivity of 78.24%, and a specificity of 69.44%. When applied to the data of CKD patients from another local hospital, the NT-proBNP to CysC1.53 ratio had a sensitivity of 70.27% and a specificity of 67.74%. Conclusion: The NT-proBNP to CysC1.53 ratio was superior to NT-proBNP alone for predicting cardiac dysfunction in patients with CKD.

Cardiovascular remodeling as a result of fibroblast growth factor-23 (FGF-23)/Klotho imbalance in patients with CKD

BACKGROUND

In chronic kidney disease (CKD) cardiovascular remodeling (CVR) is very frequent compared with general population and, as suppose, may be associated with «new» renal risk factors. The aim of study was to estimate association of new serum biomarkers (FGF-23, Klotho) and traditional biomarker of cardiac damage-serum Troponin I (sTr-I) with signs of CVR.

METHODS

One hundred thirty CKD G1-5D patients without cardiovascular disease (CVD) clinical manifestation were included. We measured serum FGF-23, Klotho and sTr-I. The instrumental methods were: echocardiography, SphygmoCor test [Pulse Wave Velocity (PWV), Central (aortic) Blood Pressure (CBP), Subendocardial Blood Supply (SBS)].

RESULTS

FGF-23 level correlated with: sTr-I (r = 0.512; p < 0.01), eccentric left ventricular hypertrophy, LVH (r = 0.543; p < 0.01), SBS (r = - 0.499; p < 0.05). There were no differences of FGF-23 level in patients with normal and high CBP. Klotho correlated with concentric LVH (r = - 0.451; p < 0.01), PWV (r = - 0.667; p < 0.001), Cardiac Calcification Score, CCS (r = - 0.581; p < 0.01). Multivariate analysis revealed positive independent association of FGF-23 with eccentric LVH (OR = 1.036, 95% CI (1.004-1.068); p = 0.038). Klotho was a negative determinant for concentric LVH (OR = 0.990, 95% CI 0.987-0.994; p < 0.001), increased PWV (OR = 0.984, 95% CI (0.977-0.991); p < 0.001) and CCS (OR = 0.991, 95% CI (0.988-0.995); p < 0.001). In addition, multivariate analysis revealed a relationship between serum Klotho (OR = 0.980, 95% CI (0.964-0.996); p = 0.016), FGF-23 (OR = 3.145, 95% CI (1.020-9.695); p = 0.046) and troponin I level.

CONCLUSION

In CKD patients without CVD clinical manifestation increased serum FGF-23 level and decreased Klotho are associated with CVR: FGF-23 with eccentric LVH (independently of CBP), Klotho determinate concentric LVH, PWV and CCS. Moderately elevated sTr-I levels may be a manifestation of FGF-23/Klotho imbalance in CKD.

Plasma biomarkers outperform echocardiographic measurements for cardiovascular risk prediction in kidney transplant recipients: results of the HOME ALONE study

Background

Since kidney transplant recipients (KTRs) have a high cardiovascular disease burden, adequate risk prediction is of importance. Whether echocardiographic parameters and plasma biomarkers, natriuretic peptides [N-terminal pro-B-type natriuretic peptide (NT-proBNP)] and troponin T provide complementary or overlapping prognostic information on cardiovascular events remains uncertain.

Methods

The prospective Heterogeneity of Monocytes and Echocardiography Among Allograft Recipients in Nephrology (HOME ALONE) study followed 177 KTRs for 5.4 ± 1.7 years. Predefined endpoints were hospitalization for acute decompensated heart failure or all-cause death (HF/D) and major atherosclerotic cardiovascular events or all-cause death (MACE/D). At baseline, plasma NT-proBNP, plasma troponin T and echocardiographic parameters [left atrial volume index, left ventricular (LV) mass index, LV ejection fraction, and LV filling pressure] were assessed.

Results

Among all echocardiographic and plasma biomarkers measured, only NT-proBNP was consistently associated with HF/D in univariate and multivariate {third versus first tertile: hazard ratio [HR] 4.20 [95% confidence interval (CI) 1.02–17.27]} analysis, and only troponin T was consistently associated with MACE/D in univariate and multivariate [third versus first tertile: HR 8.15 (95% CI 2.75–24.18)] analysis.

Conclusion

Our data suggest that plasma biomarkers are robust and independent predictors of heart failure and atherosclerotic cardiovascular events after kidney transplantation, whereas standard echocardiographic follow-up does not add to risk prediction.

Types of myocardial injury and mid-term outcomes in patients with COVID-19

AIMS

To evaluate the acute and chronic patterns of myocardial injury among patients with coronavirus disease-2019 (COVID-19), and their mid-term outcomes.

METHODS AND RESULTS

Patients with laboratory-confirmed COVID-19 who had a hospital encounter within the Mount Sinai Health System (New York City) between 27 February 2020 and 15 October 2020 were evaluated for inclusion. Troponin levels assessed between 72 h before and 48 h after the COVID-19 diagnosis were used to stratify the study population by the presence of acute and chronic myocardial injury, as defined by the Fourth Universal Definition of Myocardial Infarction. Among 4695 patients, those with chronic myocardial injury (n = 319, 6.8%) had more comorbidities, including chronic kidney disease and heart failure, while acute myocardial injury (n = 1168, 24.9%) was more associated with increased levels of inflammatory markers. Both types of myocardial injury were strongly associated with impaired survival at 6 months [chronic: hazard ratio (HR) 4.17, 95% confidence interval (CI) 3.44-5.06; acute: HR 4.72, 95% CI 4.14-5.36], even after excluding events occurring in the first 30 days (chronic: HR 3.97, 95% CI 2.15-7.33; acute: HR 4.13, 95% CI 2.75-6.21). The mortality risk was not significantly different in patients with acute as compared with chronic myocardial injury (HR 1.13, 95% CI 0.94-1.36), except for a worse prognostic impact of acute myocardial injury in patients <65 years of age (P-interaction = 0.043) and in those without coronary artery disease (P-interaction = 0.041).

CONCLUSION

Chronic and acute myocardial injury represent two distinctive patterns of cardiac involvement among COVID-19 patients. While both types of myocardial injury are associated with impaired survival at 6 months, mortality rates peak in the early phase of the infection but remain elevated even beyond 30 days during the convalescent phase.

Variability in Cardiac Biomarkers during Hemodialysis: A Prospective Cohort Study

BACKGROUND

The effect of hemodialysis on cardiac biomarkers is unclear. We sought to evaluate the degree and causes of intradialytic variability of high sensitivity troponin I (hs-TnI), galectin-3 (gal-3), and heart-type fatty acid binding protein (hFABP).

METHODS

hs-TnI, gal-3, and hFABP were prospectively measured pre-dialysis and post-dialysis for 1 week every month for 6 months in 178 prevalent adult hemodialysis patients at a single center in Hamilton, Canada. The degree of change from pre-dialysis to post-dialysis for each cardiac biomarker was estimated with multilevel linear regression models.

RESULTS

The median change in the concentration of hs-TnI during hemodialysis was -1 ng/L (interquartile range [IQR] -1 to 2 ng/L) while gal-3 and hFABP changed by -36.3 ng/mL (IQR -27.7 to -46.8 ng/mL) and -19.41 ng/mL (IQR -13.61 to -26.87 ng/mL), respectively. The median (IQR) percentage intradialytic changes for hs-TnI, gal-3, and hFABP were 2.6% (-4.4% to 12.5%), -59.8% (-54.7% to -64.8%) and -35.3% (-28.4% to -42.1%), respectively. Ultrafiltration was associated with an increase in concentration of hs-TnI, gal-3, and hFABP (mean 0.99 ng/L, 1.05 ng/mL, and 1.9 ng/mL per L ultrafiltration, respectively, P < 0.001). Both gal-3 and hFABP concentrations decreased in association with the volume of blood processed (P < 0.001) and with hemodialysis treatment time (P  = 0.02 and P  = 0.04) while hs-TnI concentration decreased only in association with hemodialysis treatment time (P  < 0.001).

CONCLUSIONS

Ultrafiltration volume and hemodialysis treatment time influenced hs-TnI, gal-3, and hFABP concentrations during hemodialysis and should be considered when interpreting their measurement.

Donor-derived cell-free DNA is associated with cardiac allograft vasculopathy

BACKGROUND

The role of donor-derived cell-free DNA (dd-cfDNA) in screening for cardiac allograft vasculopathy (CAV) is unknown. We hypothesized that dd-cfDNA correlates with CAV, markers of inflammation, and angiogenesis in stable heart transplant (HT) recipients.

METHODS

Sixty-five HT recipients ≥2 years post-transplant, without recent rejection, were stratified by high (≥0.12%) versus low levels (<0.12%) of dd-cfDNA. A targeted amplification, next-generation sequencing assay (AlloSure^® ; CareDx, Inc.) was used to detect dd-cfDNA. Peripheral blood inflammatory and angiogenesis markers were assessed using a multiplex immunoassay system (Bioplex^® ).

RESULTS

Of 65 patients, 58 patients had a known CAV status and were included. Thirty had high levels of dd-cfDNA (≥0.12%), and 28 had low levels (<0.12%). CAV was present in 63% of patients with high dd-cfDNA vs. 35% with low dd-cfDNA (p = .047). Donor-specific antibodies were present in 25% of patients with high dd-cfDNA vs. 3.8% in those with low dd-cfDNA (p = .03). There were no differences in rejection episodes, inflammatory, or angiogenesis markers. Importantly, dd-cfDNA levels were not different when stratified by time post-transplant.

CONCLUSIONS

Higher dd-cfDNA levels were associated with CAV in stable chronic HT recipients. Further studies are warranted to investigate a possible association between dd-cfDNA levels and CAV severity and whether dd-cfDNA can predict CAV progression.

Methodology to Evaluate Clinical Impact of 0/3 Hour High-Sensitivity Cardiac Troponin T Protocol on Managing Acute Coronary Syndrome in Daily Emergency Department Practice

OBJECTIVE

Sex-/age-differentiated cutoffs and the magnitude of serial changes in high-sensitivity cardiac troponins (hs-cTn) for acute coronary syndrome (ACS) diagnosis algorithms are still under discussion. This study presents a methodology to evaluate decision-making limits and to assess whether sex-specific cutoffs could improve diagnostic accuracy.

METHODS

A high-sensitivity cardiac troponin T (hs-cTnT) 0-/3-hour protocol was adopted, applying the 2015 European Society of Cardiology Guidelines. Decision-making limits (99th percentile: 14 ng/L; delta change ≥ 30%) were agreed upon with the emergency department (ED) at the University Hospital of Siena in Siena, Italy. One-year requests (5177) for hs-cTnT serial determination were compared with the final International Classification of Diseases, 9th revision, clinical modifications diagnosis (contingency tables; receiver operating characteristic curves).

RESULTS

The algorithm's capability to exclude or confirm ACS was verified by remarkable negative predictive value (97%) and high areas under the curve for the first troponin sampling (0.712), troponin sampling at 3 hours (0.789), and delta (0.744). The clinical utility for the general population-even those with comorbidities-accessing the ED was verified. Our data did not support a sex-differentiated cutoff utility because it would not have affected patient management.

CONCLUSION

This methodology allowed us to confirm the effectiveness of our decision-making limits.

A Comparison of Biomarker Rise in Type 1 and Type 2 Myocardial Infarction

BACKGROUND

Despite differing underlying pathophysiology, type 1 and type 2 myocardial infarction share many of the same diagnostic criteria and can be challenging to differentiate in clinical practice. Correctly differentiating type 1 from type 2 myocardial infarction is important because they are managed differently. The aim of this study was to compare the patterns of rise of cardiac troponin (cTn) and creatine kinase MB (CK-MB) in type 1 and type 2 myocardial infarction.

METHODS

We analyzed retrospective data on 200 patients with myocardial infarction (97 with type 1, 103 with type 2), excluding patients with ST-segment elevation myocardial infarction. The percentage rise from trough to peak values and the ratio of the peak to the upper limit of normal (RULN) were calculated for both cardiac troponin T (cTnT) and CK-MB. The ratio of peak cTnT to peak CK-MB was also calculated before and after adjusting for sex, glomerular filtration rate (GFR), and infarct size.

RESULTS

Type 1 myocardial infarction tended to be larger than type 2 myocardial infarction, with a significantly higher mean percentage rise for both cTnT and CK-MB as well as higher mean RULN (207 vs 86 for cTnT, P = 0.02; 9 vs 4 for CK-MB, P = 0.002). There was a trend toward a higher rise of cTnT than CK-MB in type 2 compared with type 1 myocardial infarction, as demonstrated by the ratio of peak cTnT to peak CK-MB (0.09 in type 2 myocardial infarction vs 0.06 in type 1 myocardial infarction, P = 0.06). This difference persisted after adjusting for sex, GFR, and infarct size (P = 0.05).

CONCLUSION

Both cTnT and CK-MB rise higher in type 1 than in type 2 myocardial infarction. Meanwhile, cTnT tends to rise out of proportion to CK-MB in type 2 myocardial infarction. These patterns may have considerable implications for the differentiation and subsequent treatment of patients with type 1 versus type 2 myocardial infarction.

Biomarkers of acute myocardial infarction: diagnostic and prognostic value. Part 1 (literature review)

Morbidity and mortality rates from acute myocardial infarction (AMI) have been growing rapidly in recent years, causing significant socio-economic damage. Cardiac biomarkers play an important role in the diagnosis and prediction of AMI. In our review article, we will summarize information about the main existing cardiac biomarkers and focus on their diagnostic and prognostic value for patients with AMI. In the first part of the review, we consider the diagnostic and prognostic value of biomarkers of necrosis and myocardial ischemia (aspartate aminotransferase; creatine phosphokinase; cardiac troponins; myoglobin, ischemia-modified albumin, fatty acid binding protein) and neuroendocrine AMI biomarkers (natriuretic peptides, adrenomedullin, catestatin, components of the renin-angiotensin-aldosterone system). In the second part of the review, we discuss the diagnostic and prognostic value of inflammatory AMI biomarkers (C-reactive protein, interleukin-6, tumor necrosis factor, myeloperoxidase, matrix metalloproteinases, soluble CD40 ligand form (sCD40L), procalcitonin, placental growth factor (PGF), procalcitonin) and recently discovered new biomarkers (microRNA, stimulating growth factor, expressed by genome 2 (ST2), growth differentiation factor 15 (GDF-15), galectin-3).

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

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

Cardiovascular outcome trials in patients with chronic kidney disease: challenges associated with selection of patients and endpoints

Although cardiovascular disease is a major health burden for patients with chronic kidney disease, most cardiovascular outcome trials have excluded patients with advanced chronic kidney disease. Moreover, the major cardiovascular outcome trials that have been conducted in patients with end-stage renal disease have not demonstrated a treatment benefit. Thus, clinicians have limited evidence to guide the management of cardiovascular disease in patients with chronic kidney disease, particularly those on dialysis. Several factors contribute to both the paucity of trials and the apparent lack of observed treatment effect in completed studies. Challenges associated with conducting trials in this population include patient heterogeneity, complexity of renal pathophysiology and its interaction with cardiovascular disease, and competing risks for death. The Investigator Network Initiative Cardiovascular and Renal Clinical Trialists (INI-CRCT), an international organization of academic cardiovascular and renal clinical trialists, held a meeting of regulators and experts in nephrology, cardiology, and clinical trial methodology. The group identified several research priorities, summarized in this paper, that should be pursued to advance the field towards achieving improved cardiovascular outcomes for these patients. Cardiovascular and renal clinical trialists must partner to address the uncertainties in the field through collaborative research and design clinical trials that reflect the specific needs of the chronic and end-stage kidney disease populations, with the shared goal of generating robust evidence to guide the management of cardiovascular disease in patients with kidney disease.

Analysis of influencing factors related to elevated serum troponin I level for COVID-19 patients in Yichang, China

Background

Cardiac injury is a common condition among hospitalized coronavirus disease 2019 (COVID-19) patients, and is associated with a higher risk of mortality. However, the mechanism of myocardial injury in COVID-19 remains unclear. In this retrospective study, we compared the clinical characteristics of COVID-19 patients with different troponin I (TnI) levels during hospitalization to provide a clinical reference for the identification of those at high-risk.

Methods

In total, 218 patients diagnosed with COVID-19 in Yichang Central People's Hospital and Yichang Third People's Hospital between January 23 and February 19, 2020 were initially included. Of these patients, 89 underwent TnI testing during hospitalization and were finally included in the study. The medical history, clinical signs and symptoms at the time of admission, and laboratory test results were recorded. The patients were assigned to the normal TnI group (TnI <0.01 µg/L; n=67) or the elevated TnI group (TnI >0.01 µg/L; n=22).

Results

The incidence of elevated TnI in our patient cohort was 24.7%. There were significant differences between the two groups in the following factors: history of coronary heart disease (CHD), age, lymphocyte count, prothrombin time (PT), activated partial thromboplastin time (APTT), and levels of interleukin (IL)-6, C-reactive protein (CRP), myoglobin (MYO), lactate dehydrogenase (LDH), and albumin (all P<0.05). Binary logistic analysis showed that a history of CHD, age, lymphocyte count, IL-6, APTT, and MYO were influencing factors of elevated serum TnI.

Conclusions

A history of CHD, advanced age, decreased lymphocyte count, increased IL-6, increased MYO, and prolonged APTT were independent influencing factors of elevated TnI in COVID-19 patients. COVID-19 patients with these characteristics are prone to myocardial injury.

Ideal high sensitivity troponin baseline cutoff for patients with renal dysfunction

OBJECTIVE

High-sensitivity cardiac troponin assays (hs-cTn) aid in diagnosis of myocardial infarction (MI). These assays have lower specificity for non-ST Elevation MI (NSTEMI) in patients with renal disease. Our objective was to determine an optimized cutoff for patients with renal disease.

METHODS

We conducted an a priori secondary analysis of a prospective FDA study in adults with suspected MI presenting to 29 academic urban EDs between 4/2015 and 4/2016. Blood was drawn 0, 1, 2-3, and 6-9 h after ED arrival. We recorded cTn and estimated glomerular filtrate rate (eGFR) by Chronic Kidney Disease Epidemiology Collaboration equation. The primary endpoint was NSTEMI (Third Universal Definition of MI), adjudicated by physicians blinded to hs-cTn results. We generated an adjusted hscTn rule-in cutoff to increase specificity.

RESULTS

2505 subjects were enrolled; 234 were excluded. Patients were mostly male (55.7%) and white (57.2%), median age was 56 years 472 patients [20.8%] had an eGFR <60 mL/min/1.73 m2. In patients with eGFR <15 mL/min/1.73 m2, a baseline rule-in cutoff of 120 ng/L led to a specificity of 85.0% and Positive Predictive Value (PPV) of 62.5% with 774 patients requiring further observation. Increasing the cutoff to 600 ng/L increased specificity and PPV overall and in every eGFR subgroup (specificity and PPV 93.3% and 78.9%, respectively for eGFR <15 mL/min/1.73m²), while increasing the number (79) of patients requiring observation.

CONCLUSIONS

An eGFR-adjusted baseline rule-in threshold for the Siemens Atellica hs-cTnI improves specificity with identical sensitivity. Further study in a prospective cohort with higher rates of renal disease is warranted.

Associations between estimated glomerular filtration rate and cardiac biomarkers

BACKGROUND

Chronic kidney disease (CKD) is associated with an increased cardiovascular disease (CVD) mortality risk. Elevation of cardiac biomarkers in patients with renal dysfunction is ambiguous in the diagnosis of CVD. The purpose of this study was to investigate the associations between estimated glomerular filtration rate (eGFR) and cardiac biomarkers, and the influence of renal dysfunction on the cardiac biomarkers.

METHODS

We examined the cross-sectional associations of eGFR with cardiac troponin I (cTnI), creatine kinase (CK), CK-MB, lactic dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HBDH), and brain natriuretic peptide (BNP) in 812 adults and 215 child. Spearman correlation and logistic regression analysis were performed to evaluate the associations.

RESULTS

For adults, lower eGFR _CKD-EPI had significantly higher cTnI, CK-MB, LDH, HBDH, and BNP. There were negative correlations between eGFR_CKD-EPI and cTnI, CK-MB, LDH, HBDH, and BNP. After adjustment for potential confounders, as compared with eGFR_CKD-EPI  ≥ 90 mL/min/1.73 m² , eGFR_CKD-EPI  < 60 mL/min/1.73 m² remained associated with a 2.83 (1.08-7.41) [ratio (95% CI)] times higher cTnI and a 6.50 (2.32-18.22) [ratio (95% CI)] times higher HBDH. For child, lower eGFR_Schwartz had significant higher CK and CK-MB. There were negative correlations between eGFR_Schwartz and CK, and eGFR_Schwartz and CK-MB. After adjustment for potential confounders, as compared with eGFR_Schwartz  ≥ 90 mL/min/1.73 m² , eGFR_Schwartz  < 90 mL/min/1.73 m² revealed no significant higher CVD biomarkers.

CONCLUSION

Reduced eGFR is associated with elevated cTnI and HBDH among adults without clinically evident CVD, but not child.

Novel Biomarkers in Patients with Chronic Kidney Disease: An Analysis of Patients Enrolled in the GCKD-Study

Background: Chronic kidney disease (CKD) and cardiovascular diseases (CVD) often occur concomitantly, and CKD is a major risk factor for cardiovascular mortality. Since some of the most commonly used biomarkers in CVD are permanently elevated in patients with CKD, novel biomarkers are warranted for clinical practice. Methods: Plasma concentrations of five cardiovascular biomarkers (soluble suppression of tumorigenicity (sST2), growth differentiation factor 15 (GDF-15), heart-type fatty acid-binding protein (H-FABP), insulin-like growth factor-binding protein 2 (IGF-BP2), and soluble urokinase plasminogen activator receptor) were analyzed by means of enzyme-linked immunosorbent assay (ELISA) in 219 patients with CKD enrolled in the German Chronic Kidney Disease (GCKD) study. Results: Except for sST2, all of the investigated biomarkers were significantly elevated in patients with CKD (2.0- to 4.4-fold increase in advanced CKD (estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m² body surface area (BSA)) and showed a significant inverse correlation with eGFR. Moreover, all but H-FABP and sST2 were additionally elevated in patients with micro- and macro-albuminuria. Conclusions: Based on our findings, sST2 appears to be the biomarker whose diagnostic performance is least affected by decreased renal function, thus suggesting potential viability in the management of patients with CVD and concomitant CKD. The predictive potential of sST2 remains to be proven in endpoint studies.

Optimal cut-off value of high-sensitivity troponin I in diagnosing myocardial infarction in patients with end-stage renal disease

End-stage renal disease (ESRD) is a major risk factor for cardiovascular disease and the prognosis after myocardial infarction (MI) is dismal. Although cardiac troponin is a key diagnostic test, troponin levels are often elevated in ESRD patients without evidence of MI. Thus, this study attempted to determine the optimal diagnostic value of high-sensitivity troponin I (hsTnI) by dialysis modality in ESRD patients.Medical records of adult dialysis patients who visited tertiary emergency department (ED) were collected retrospectively. Diagnosis of MI was made according to the fourth universal definition of MI. The cut-off values were calculated using a receiver operating characteristic (ROC) curve.Medical records of 1144 patients were analyzed and MI was diagnosed in 82 patients (75 on hemodialysis and 7 on peritoneal dialysis). The optimal cut-off value of hsTnI in hemodialysis patients was 75 ng/L, with 93.33% sensitivity and 60.76% specificity. Area under the curve (AUC) was .870 (95% confidence interval (CI) .833-.906). The optimal cut-off value of hsTnI in peritoneal dialysis patients was 144 ng/L, with 100.00% sensitivity and 83.10% specificity. AUC was .943 (95% CI .893-.992).The dialysis modality should also be considered when diagnosing MI using hsTnI in ESRD patients.

Association Between Renal Function and Troponin T Over Time in Stable Chronic Kidney Disease Patients

Background

People with reduced glomerular filtration rate (GFR) often have elevated cardiac troponin T (cTnT) levels. It remains unclear how cTnT levels develop over time in those with chronic kidney disease (CKD). The aim of this study was to prospectively study the association between cTnT and GFR over time in older advanced‐stage CKD patients not on dialysis.

Methods and Results

The EQUAL (European Quality Study) study is an observational prospective cohort study in stage 4 to 5 CKD patients aged ≥65 years not on dialysis (incident estimated GFR, <20 mL/min/1.73 m²). The EQUAL cohort used for the purpose of this study includes 171 patients followed in Sweden between April 2012 and December 2018. We used linear mixed models, adjusted for important groups of confounders, to investigate the effect of both measured GFR and estimated GFR on high‐sensitivity cTnT (hs‐cTnT) trajectory over 4 years. Almost all patients had at least 1 hs‐cTnT measurement elevated above the 99th percentile of the general reference population (≤14 ng/L). On average, hs‐cTnT increased by 16%/year (95% CI, 13–19; P<0.0001). Each 15 mL/min/1.73 m² lower mean estimated GFR was associated with a 23% (95% CI, 14–31; P<0.0001) higher baseline hs‐cTnT and 9% (95% CI, 5–13%; P<0.0001) steeper increase in hs‐cTnT. The effect of estimated GFR on hs‐cTnT trajectory was somewhat lower than a previous myocardial infarction (15%), but higher than presence of diabetes mellitus (4%) and male sex (5%).

Conclusions

In CKD patients, hs‐cTnT increases over time as renal function decreases. Lower CKD stage (each 15 mL/min/1.73 m² lower) is independently associated with a steeper hs‐cTnT increase over time in the same range as other established cardiovascular risk factors.

High-sensitivity troponin assays: development and utility in a modern health-care system

Introduction: The introduction of cardiac troponin (cTn) assays have revolutionized the diagnosis and management of acute myocardial infarction in Emergency Departments worldwide. Its success has led to significant research and development investment in this area culminating in the development of newer high-sensitivity cardiac troponin assays (hs-cTn). While these newer assays allow for more rapid diagnosis by decreasing the time interval between serial data points, there is an inevitable trade off between increasing sensitivity and specificity. This review examines in detail the introduction and implementation of hs-cTN and its implications for clinical practice.Areas covered: This article reviews the history and development of high-sensitivity troponin assays and their application to clinical practice and current evidence base. It also discusses both the positive and negative aspects of the continuing increasing sensitivity of biochemical assays and the translation of this into clinical practice. Potential future developments are also discussed.Expert commentary: It is clear that there are many benefits to detecting extremely low concentration of cardiac troponin including the development of rapid rule out algorithms and the cost and time-saving advantages associated with the quicker movement of patients through the health-care system. It is important to note however that detecting troponin at very low concentrations also dramatically increases the false-positive rates and leads to a potentially large increase in invasive testing and diagnosis of myocardial infarction.

Serum troponin-I as a marker of fibroblast growth factor-23 (FGF-23) cardiotoxic effect, in patients with chronic kidney disease

Aim. It has been established that an increased fibroblast growth factor (FGF-23) serum levels significantly contribute to the heart and blood vessels remodeling in patients with chronic kidney disease (CKD). But the precise mechanisms of the FGF-23 cardiac effect are currently being actively studied. At the same time, it is believed that the cardiac effects of FGF-23 may be due to the increasing deficit of Klotho protein as CKD progresses. In parallel with these changes, a number of studies indicate the persistence of the detectable troponins serum levels in CKD patients, even in the absence of clear clinical manifestations of cardiovascular diseases (CVD). The aim of the study was to confirm / exclude the existence of a causal relationship between elevated FGF-23, reduced Klotho and elevated troponin-I (as the most specific troponin in CKD). Materials and methods. The study included 130 CKD stages 1-5D patients without clinically pronounced symptoms of СVD (Coronary artery disease, CCS class 2-4, Chronic heart failure, NYHA 24, myocarditis, pericarditis, arrhythmias), as well as the severe arterial hypertension (BP >160/90 mm Hg), according to the laboratory and instrumental methods of examination. The selected group of patients was studied: serum levels of FGF-23 (Human FGF-23 ELISA kit), Klotho (Human soluble Klotho with antiklotho monoclonal antibodies), troponin-I (high - sensitive assay), and also data from instrumental examination methods: electrocardiography (ECG), echocardiography (left ventricular myocardial mass index (LVMI), cardiac (valvular) calcification score (CCS) using a semi - quantitative point scale), sphygmagraphy (augmentation (stiffness) indices of vessels (AI), pulse wave velocity (PWV), central (aortic) blood pressure (CBP), blood supply of subendocardium (BSE) - using "Shygmacor" device (Australia)). Results and discussion. The changes in serum levels of FGF-23, Klotho and troponin-I (Tr-I) depended on the stage of CKD. The following correlations were identified: FGF-23 and: Tr-I (r=0.601; p

Diagnosis and treatment of myocardial infarction in patient with end - stage renal disease on chronic hemodialysis

This review represents different aspects of myocardial infarction in patient with end - stage renal disease on chronic hemodialysis. We discuss difficulties in diagnosis, optimal method of coronary revascularization, timing of hemodialysis session, medical therapy, as well as epidemiology and prognosis. There are no unambiguous answers to these problems because patients with end - stage renal disease were excluded from most of the studies.

Diagnostic and prognostic value of biomarkers in acute myocardial infarction

The incidence of acute myocardial infarction (AMI) has been increasing rapidly in recent years, seriously endangering human health. Cardiac biomarkers play critical roles in the diagnosis and prognosis of AMI. Troponin is a highly sensitive and specific biomarker for AMI diagnosis and can independently predict adverse cardiac events. Other biomarkers such as N-terminal B-type natriuretic peptide and C reactive protein are also valuable predictors of cardiovascular prognosis. Recently, several novel biomarkers have been identified for the diagnosis and risk assessment in patients with AMI. A multibiomarker approach can potentially enhance the diagnostic accuracy and provide more information for the early risk stratification of AMI. In this review, we will summarise the biomarkers discovered in recent years and focus on their diagnostic and prognostic value for patients with AMI.

Cardiac troponins in chronic kidney disease patients with special emphasis on their importance in acute coronary syndrome

Troponin measurement is one of crucial assessments facilitating diagnosis of acute coronary syndrome. Patients with chronic kidney disease are decimated by cardiovascular disease. Unfortunately, elevated concentration of serum troponin is commonly faced in clinical practice creating a challenge to rule out acute cardiac ischaemia in this vulnerable population. This review presents current knowlegde on analytical differences in troponin T and I measurements, their prognostic significance and their application in diagnosing acute coronary syndrome in chronic kidney disease patients. It also points out poorly known aspects and suggests directions for future research.

Challenges in high-sensitive troponin assay interpretation for intensive therapy

Cardiac troponins T and I are considered highly sensitive and specific markers for the diagnosis of acute myocardial infarction. Currently, a series of nonprimary cardiac abnormalities may manifest as an elevation in high-sensitive assays. The reduction in their detection limits has allowed earlier diagnosis and the use of evidence-based therapeutic measures; however, this characteristic has increased the spectrum of detectable noncoronary heart diseases, which poses challenges for characterizing acute coronary syndromes and creates a new role for these tests in known disorders in intensive care units, especially sepsis. Management of patients through a greater understanding of how these markers behave should be re-evaluated to ensure their correct interpretation.

Predictors of atherosclerotic events in patients on haemodialysis: post hoc analyses from the AURORA study

Background

Patients on haemodialysis (HD) are at high risk for cardiovascular events, but heart failure and sudden death are more common than atherosclerotic events. The A Study to Evaluate the Use of Rosuvastatinin in Subjects on Regular Hemodialysis: An Assessment of Survival and Cardiovascular Events (AURORA) trial was designed to assess the effect of rosuvastatin on myocardial infarction and death from any cardiac cause in 2773 HD patients. We studied predictors of the atherosclerotic cardiovascular events in AURORA.

Methods

We readjudicated all deaths and presumed myocardial infarctions according to the criteria used in the Study of Heart and Renal Protection (SHARP); these were specifically developed to separate atherosclerotic from non-atherosclerotic cardiovascular events. The readjudicated atherosclerotic end point included the first event of the following: non-fatal myocardial infarction, fatal coronary heart disease, non-fatal and fatal non-haemorrhagic stroke, coronary revascularization procedures and death from ischaemic limb disease. Stepwise Cox regression analysis was used to identify the predictors of such events.

Results

During a mean follow-up of 3.2 years, 506 patients experienced the new composite atherosclerotic outcome. Age, male sex, prevalent diabetes, prior cardiovascular disease, weekly dialysis duration, baseline albumin [hazard ratio (HR) 0.96; 95% confidence interval (CI) 0.94-0.99 per g/L increase], high-sensitivity C-reactive protein (HR 1.13; 95% CI 1.04-1.22 per mg/L increase) and oxidized low-density lipoprotein (LDL) cholesterol (HR 1.09; 95% CI 1.03-1.17 per 10 U/L increase) were selected as significant predictors in the model. Neither LDL cholesterol nor allocation to placebo/rosuvastatin therapy predicted the outcome.

Conclusions

Even with the use of strict criteria for end point definition, non-traditional risk factors, but not lipid disturbances, predicted atherosclerotic events in HD patients.

Adjusted Troponin I for Improved Evaluation of Patients with Chest Pain

The use of cardiac troponins (cTn) is the gold standard for diagnosing myocardial infarction. Independent of myocardial infarction (MI), however, sex, age and kidney function affect cTn levels. Here we developed a method to adjust cTnI levels for age, sex, and renal function, maintaining a unified cut-off value such as the 99th percentile. A total of 4587 individuals enrolled in a prospective longitudinal study were used to develop a model for adjustment of cTn. cTnI levels correlated with age and estimated glomerular filtration rate (eGFR) in males/females with rage = 0.436/0.518 and with reGFR = -0.142/-0.207. For adjustment, these variables served as covariates in a linear regression model with cTnI as dependent variable. This adjustment model was then applied to a real-world cohort of 1789 patients with suspected acute MI (AMI) (N = 407). Adjusting cTnI showed no relevant loss of diagnostic information, as evidenced by comparable areas under the receiver operator characteristic curves, to identify AMI in males and females for adjusted and unadjusted cTnI. In specific patients groups such as in elderly females, adjusting cTnI improved specificity for AMI compared with unadjusted cTnI. Specificity was also improved in patients with renal dysfunction by using the adjusted cTnI values. Thus, the adjustments improved the diagnostic ability of cTnI to identify AMI in elderly patients and in patients with renal dysfunction. Interpretation of cTnI values in complex emergency cases is facilitated by our method, which maintains a single diagnostic cut-off value in all patients.

Prooxidant-antioxidant balance, hsTnI and hsCRP: mortality prediction in haemodialysis patients, two-year follow-up

Oxidative stress and inflammation are highly intertwined pathophysiological processes. We analyzed the markers of these processes and high-sensitive troponin I (hsTnI) for mortality prediction in patients on haemodialysis. This study enrolled a total of 62 patients on regular haemodialysis. The patients were monitored for two years, and the observed outcomes were all-cause and cardiovascular mortality. Blood samples were taken before one dialysis session for analysis of the baseline concentrations of prooxidant–antioxidant balance (PAB), total antioxidant status (TAS), total oxidative status (TOS), hsTnI, hsCRP and resistin. The overall all-cause mortality was 37.1% and CVD mortality 16.1%. By univariate and multivariate logistic regression, our findings suggest that good predictors of all-cause mortality include hsCRP and PAB (p < .05) and of CVD mortality hsCRP (p < .05) and hsTnI (p < .001). To evaluate the relationship between the combined parameter measurements and all-cause/CVD mortality risk, patients were divided into three groups according to their PAB, hsCRP and hsTnI concentrations. The cutoffs for hsCRP and hsTnI and the median for PAB were used. Kaplan–Meier survival curves pointed out that the highest mortality risk of all-cause mortality was in the group with hsCRP levels above the cutoff and PAB levels above the median (p < .001). The highest risk of CVD mortality was found in the group with hsCRP and hsTnI levels above the cutoff levels (p = .001). Our data suggest that hsCRP and PAB are very good predictors of all-cause mortality. For CVD complications and mortality prediction in HD patients, the most sensitive parameters appear to be hsTnI and hsCRP.

Renal Dysfunction Influences the Diagnostic and Prognostic Performance of High-Sensitivity Cardiac Troponin I

Measures of cardiac troponin (cTn) may have lower specificity for myocardial infarction in patients with CKD. We examined the diagnostic accuracy of baseline and serial high-sensitivity cTnI (hs-cTnI) measurements for myocardial infarction and 30- and 180-day mortality according to renal function. hs-cTnI was measured (Abbott assay) using sex-specific 99th percentiles (women, 16 ng/L; men, 34 ng/L) in 1555 adults presenting to the emergency department with symptoms suggesting ischemia (NCT02060760). Myocardial infarction was adjudicated along universal definition classification. Renal function did not significantly affect sensitivity or negative predictive values. Specificity decreased with impaired renal function from 93%-95% with normal function (eGFR≥90 ml/min per 1.73 m2; n=722) to 57%-61% with severely impaired renal function (eGFR<30 ml/min per 1.73 m2; n=81) and 40%-41% on dialysis (n=78). Positive predictive values decreased with decreasing renal function from 51%-57% with normal function to 27%-42% with severely impaired function and 15%-32% on dialysis. Receiver operating characteristic curve areas trended lower at baseline and 3 hours with renal impairment. Mortality increased significantly with increasing hs-cTnI tertile (1.3%, 6.0%, and 10.4%, respectively). Patients with hs-cTnI concentration exceeding concentrations in the 99th percentiles had a mortality rate (11.7%) significantly higher than that of patients with concentrations between 99th percentile concentrations and limit of detection (6.2%) or below limit of detection (1.1%). Renal dysfunction and dialysis reduced the rule-in performance but not the rule-out performance of hs-cTnI for myocardial infarction, and mortality increased in patients with higher hs-cTnI concentrations and any level of renal dysfunction.