Association Between High-Sensitivity Cardiac Troponin T and Echocardiographic Parameters in Chronic Kidney Disease: Results From the KNOW-CKD Cohort Study

Kidney function-specific cut-off values of high-sensitivity cardiac troponin T for the diagnosis of acute myocardial infarction

Background

The diagnosis of acute myocardial infarction (AMI) using high-sensitivity cardiac troponin T (hs-cTnT) remains challenging in patients with kidney dysfunction.

Methods

In this large, multicenter cohort study, a total of 20 912 adults who underwent coronary angiography were included. Kidney function-specific cut-off values of hs-cTnT were determined to improve the specificity without sacrificing sensitivity, as compared with that using traditional cut-off value (14 ng/L) in the normal kidney function group. The diagnostic accuracy of the novel cut-off values was validated in an independent validation cohort.

Results

In the derivation cohort (n = 12 900), 3247 patients had an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Even in the absence of AMI, 50.2% of participants with eGFR <60 mL/min/1.73 m2 had a hs-cTnT concentration ≥14 ng/L. Using 14 ng/L as the threshold of hs-cTnT for diagnosing AMI led to a significantly reduced specificity and positive predictive value in patients with kidney dysfunction, as compared with that in patients with normal kidney function. The kidney function-specific cut-off values were determined as 14, 18 and 48 ng/L for patients with eGFR >60, 60-30 and <30 mL/min/1.73 m2, respectively. Using the novel cut-off values, the specificities for diagnosing AMI in participants with different levels of kidney dysfunction were remarkably improved (from 9.1%-52.7% to 52.8-63.0%), without compromising sensitivity (96.6%-97.9%). Similar improvement of diagnostic accuracy was observed in the validation cohort (n = 8012).

Conclusions

The kidney function-specific cut-off values of hs-cTnT may help clinicians to accurately diagnose AMI in patients with kidney dysfunction and avoid the potential overtreatment in practice.

Early Serum Biomarkers of Cardiovascular Disease in Elderly Patients with Chronic Kidney Disease

BACKGROUND

The global population is aging. It is estimated that by 2050, the proportion of the elderly population will reach 16%. Various studies have suggested that elderly people have a greater incidence of CKD. These elderly patients are also susceptible to cardiovascular disease (CVD), which is the leading cause of death, resulting in poor prognosis in this population. However, CVD in such patients is often insidious and lacks early markers for effective evaluation. Fortunately, several studies have recently proposed biomarkers associated with this process.

SUMMARY

This study aimed to summarize the early biomarkers of CVD in elderly patients with CKD to provide a basis for its prevention and treatment.

KEY MESSAGES

This review outlines four categories of potential early biomarkers. All of them have been shown to have some clinical value for these patients, but more research is still needed.

Urine High-Sensitive Troponin T-Novel Biomarker of Myocardial Damage in Children

Background

The use of high-sensitive cardiac troponin T (hsTnT) in urine as a marker of cardiac damage in children has not yet been reported. Elimination of cardiac troponins is dependent on renal function; persistently increased serum hsTnT concentrations were observed among individuals with impaired renal function. The aim of this study was to investigate serum and urine hsTnT levels and its correlation in infants and children younger than 24 months of age after cardiac surgery.

Methods

This study was conducted on 90 infants and children under 24 months of age who were divided into three groups. The experimental group consisted of patients with intracardiac surgery of ventricular septal defect (VSD), first control group consisted of infants with extracardiac formation of bidirectional cavopulmonary connection (BCPC), and the second control group consisted of healthy children. Troponin T values ​​were determined in serum and urine at five time points: the first sample was taken on the day before cardiac surgery (measure 0) and the other four samples were taken after the surgery; immediately after (measure 1), on the first (measure 2), third (measure 3), and fifth postoperative day (measure 5). The first morning urine was sampled for determining the troponin T in the control group of healthy infants.

Results

A positive correlation between troponin T values in serum and urine was found. Urine hsTnT measured preoperatively in children undergoing BCPC surgery was higher (median 7.3 [IQR 6.6-13.3] ng/L) compared to children undergoing VSD surgery (median 6.5 [IQR 4.4-8.9] ng/L) as well as to healthy population (median 5.5 [IQR 5.1-6.7] ng/L). After logarithmic transformation, there was no statistically significant difference in urine hsTnT concentration between the groups at any point of measurement preoperatively or postoperatively. Statistically significant negative correlation was found between serum and urine hsTnT concentrations and glomerular filtration rate estimated by creatinine clearance. Patients who underwent surgical repair of VSD had significantly higher concentrations of troponin T in serum on the first three postoperative measurements compared to those who had BCPC surgery.

Conclusions

According to the results of this study, renal function after cardiac surgery appears to have a major effect on the urinary hsTnT concentrations, and we cannot conclude that this is an appropriate marker for the assessment of postoperative myocardial damage in children. Nevertheless, more research is needed to reach a better understanding of the final elimination of cardiac troponins in children.

Association of Serum Osteoprotegerin Level With Myocardial Injury and Cardiovascular Calcification in Chronic Kidney Disease Patients

Background

Chronic kidney disease has emerged as a significant independent risk factor for cardiovascular disease. Cardiovascular calcification is an active process involving a complex interaction of inducers and inhibitors. High sensitivity cardiac troponin T assay detects troponin T with higher sensitivity and precision at an earlier point of time than the conventional assays, and is associated with poor outcomes. Serum osteoprotegerin is classed as an inhibitory factor for cardiovascular calcification. It is involved in the pathological processes of vascular damage and linked to the excess cardiovascular morbidity. The aim of the present study was to evaluate the extent of cardiovascular calcification and serum high sensitivity cardiac troponin T level, and their association with serum osteoprotegerin level in patients with chronic kidney disease stages 3-5.

Methods

90 chronic kidney disease patients were enrolled in this study, and they were divided into two groups: group (1) included 45 non-dialysis-dependent chronic kidney disease patients (stages 3-5) and group (2) included 45 chronic hemodialysis patients. Each group further subdivided according to the presence of cardiovascular calcification into subgroup A and B. Vascular calcifications were assessed by lateral lumbar, pelvis and hands X-ray radiographs. Valvular calcification was assessed by echocardiography. Serum cardiac troponin T was measured by high sensitivity assay and serum osteoprotegerin was measured by ELISA.

Results

Cardiovascular calcification distribution was 22.2% in group (1) and 33.3% in group (2). Serum osteoprotegerin and troponin T in calcification groups (1A and 2A) were significantly higher than non-calcification groups (1B and 2B; P < 0.001). Osteoprotegerin correlated positively with high sensitivity cardiac troponin T (rs = 0.72, P < 0.001). cardiovascular calcification correlated positively with osteoprotegerin, troponin T, and phosphorus. osteoprotegerin and phosphorus were significant independent predictors of cardiovascular calcification at cut-off values ≥4.6 ng/L and ≥6.95 mg/dl, respectively (P < 0.001). Serum phosphorus and creatinine were independent predictors of osteoprotegerin (P < 0.001 and 0.048, respectively).

Conclusion

Osteoprotegerin is strongly associated with cardiovascular calcification and high sensitivity cardiac troponin T. In addition, there is a positive association between calcification and troponin T. This suggests a role for osteoprotegerin in the pathogenesis and risk stratification of cardiovascular calcification and myocardial injury in chronic kidney disease patients with a potential role as a therapeutic target.

Cardiac biomarkers in pediatric CKD-a prospective follow-up study

BACKGROUND

The N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitive cardiac-specific troponin T (hs-cTnT) are associated with abnormal cardiac structure and function and an increased risk of cardiovascular death in chronic kidney disease (CKD) patients. There is limited knowledge about these cardiac markers in pediatric CKD patients.

METHODS

Longitudinal levels of NT-proBNP and hs-cTnT were analyzed in 48 pediatric patients, 22 with CKD (GFR range 8.8-68 mL/min/1.73 m²) and 26 transplanted patients (CKD-T; GFR range 30-99 mL/min/1.73 m²). Follow-up was scheduled after 1 and 3 years. Longitudinal patterns and associations to kidney function, cardiovascular risk markers, and echocardiographic parameters were assessed.

RESULTS

High NT-proBNP was present in 27% of CKD and 11% of CKD-T patients. Similarly 32% of CKD and 8% of CKD-T patients had elevated hs-cTnT levels. In longitudinal multivariate analyses, high log NT-proBNP was associated with low GFR (β =  - 0.01, p = 0.01) and elevated left ventricular mass index (LVMI; β = 0.02, p = 0.05). The strong association to LVMI remained when using GFR-adjusted NT-proBNP in similar analysis. Patients with left ventricular hypertrophy (LVH) also had higher NT-proBNP (235 [146-301] ng/L) than patients without LVH (86 [11-477] ng/L), p = 0.02. High hs-cTnT over-time was also associated with low GFR (β =  - 0.007, p = 0.01) and a low cc-TDI e´/a´, indicating a worse LV diastolic function (β =  - 0.09, p = 0.05). This association did not persist for GFR-adjusted hs-cTnT.

CONCLUSIONS

NT-proBNP and hs-cTnT are elevated in pediatric CKD and CKD-T patients. GFR-adjusted NT-proBNP was associated with longitudinal levels of elevated LVMI suggesting this might be a marker for early subclinical myocardial damage. A higher resolution version of the Graphical abstract is available as Supplementary information.

Abnormalities in Cardiac Structure and Function among Individuals with CKD: The COMBINE Trial

Background

Individuals with CKD have a high burden of cardiovascular disease (CVD). Abnormalities in cardiac structure and function represent subclinical CVD and can be assessed by cardiac magnetic resonance imaging (cMRI).

Methods

We investigated differences in cMRI parameters in 140 individuals with CKD stages 3b-4 who participated in the CKD Optimal Management with BInders and NicotinamidE (COMBINE) trial and in 24 age- and sex-matched healthy volunteers. Among COMBINE participants, we examined the associations of eGFR, urine albumin-creatinine ratio (UACR), phosphate, fibroblast growth factor 23 (FGF23), and parathyroid hormone (PTH) with baseline (N=140) and 12-month change (N=112) in cMRI parameters.

Results

Mean (SD) ages of the COMBINE participants and healthy volunteers were 64.9 (11.9) and 60.4 (7.3) years, respectively. The mean (SD) baseline eGFR values in COMBINE participants were 32.1 (8.0) and 85.9 (16.0) ml/min per 1.73 m² in healthy volunteers. The median (interquartile range [IQR]) UACR in COMBINE participants was 154 (20.3-540.0) mg/g. Individuals with CKD had lower mitral valve E/A ratio compared with healthy volunteers (for CKD versus non-CKD, β estimate, -0.13; 95% CI, -0.24 to -0.012). Among COMBINE participants, multivariable linear regression analyses showed that higher UACR was significantly associated with lower mitral valve E/A ratio (β estimate per 1 unit increase in natural-log UACR, -0.06; 95% CI, -0.09 to -0.03). This finding was preserved among individuals without baseline CVD. UACR was not associated with 12-month change in any cMRI parameter. eGFR, phosphate, FGF23, and PTH were not associated with any cMRI parameter in cross-sectional or change analyses.

Conclusions

Individuals with CKD stages 3b-4 have evidence of cMRI abnormalities. Albuminuria was independently associated with diastolic dysfunction, as assessed by mitral valve E/A ratio, in individuals with CKD with and without clinical CVD. Albuminuria was not associated with change in any cMRI parameter.

Distribution and specificity of high-sensitivity cardiac troponin T in older adults without acute cardiac conditions: cross-sectional results from the population-based AugUR study

OBJECTIVE

European guidelines recommended a uniform upper reference limit of high-sensitivity cardiac troponin T (hsTnT) to rule out non-ST segment elevation myocardial infarction. Our study aimed to provide a hsTnT reference distribution and to assess the specificity of the 14 ng/L cut-off value in the mobile population ≥70 years of age.

DESIGN

A cross-sectional analysis was performed in the German AugUR study (Altersbezogene Untersuchungen zur Gesundheit der University of Regensburg).

SETTING

Study population was the mobile population aged 70+ years living in the city and county of Regensburg, Germany.

PARTICIPANTS

A random sample was derived from the local population registries of residence. Of the 5644 individuals invited, 1133 participated (response ratio=20.1%). All participants came to the study centre and were mentally and physically mobile to conduct the protocol (face-to-face interview, blood draw and standardised transthoracic echocardiography). None of the participants was in an acute state of myocardial infarction.

RESULTS

Among the 1129 individuals with hsTnT measurements (overall median=10.0 ng/L(25th, 75th percentile)=(7.0, 15.0 ng/L)), hsTnT was higher among the older individuals and higher among men (men 70-74 years median=9.6 ng/L (7.2, 13.1 ng/L); men 90-95 years median=21.2 ng/L (14.6, 26.0 ng/L); women 70-74 years median=6.3 ng/L (4.7, 8.7 ng/L); and women 90-95 years median=18.0 ng/L (11.0, 21.0 ng/L)). In participants with impaired kidney function (eGFR_crea <60 mL/min/1.73 m²), hsTnT was elevated (median=13.6 ng/L (9.4, 20.6 ng/L)).Specificity of recommended upper reference limit, 14 ng/L, is 68%. Most false positives were among men aged >79 years (specificity=34%). In a healthy subgroup (n=96, none of the following: overt heart disease, impaired renal function, blood pressure >160/100 mm Hg, left ventricular hypertrophy and diastolic/systolic dysfunction), specificity was 90%.

CONCLUSION

In the elderly population without acute myocardial infarction, hsTnT further increases with age showing different levels for men and women. The specificity of the 14 ng/L cut-off is considerably lower than 99%, even in healthy subjects.

Fibrosis, the Bad Actor in Cardiorenal Syndromes: Mechanisms Involved

Cardiorenal syndrome is a term that defines the complex bidirectional nature of the interaction between cardiac and renal disease. It is well established that patients with kidney disease have higher incidence of cardiovascular comorbidities and that renal dysfunction is a significant threat to the prognosis of patients with cardiac disease. Fibrosis is a common characteristic of organ injury progression that has been proposed not only as a marker but also as an important driver of the pathophysiology of cardiorenal syndromes. Due to the relevance of fibrosis, its study might give insight into the mechanisms and targets that could potentially be modulated to prevent fibrosis development. The aim of this review was to summarize some of the pathophysiological pathways involved in the fibrotic damage seen in cardiorenal syndromes, such as inflammation, oxidative stress and endoplasmic reticulum stress, which are known to be triggers and mediators of fibrosis.

Association of maximal stress ergometry performance with troponin T and abdominal aortic calcification score in advanced chronic kidney disease

Background

Cardiac biomarkers Troponin T (TnT) and N-terminal pro-B-type natriuretic peptide (proBNP) and abdominal aortic calcification score (AAC) are associated with cardiovascular events and mortality in patients with chronic kidney disease (CKD). The effects of cardiac biomarkers and AAC on maximal exercise capacity in CKD are unknown and were studied.

Methods

One hundred seventy-four CKD 4–5 patients not on maintenance dialysis underwent maximal bicycle ergometry stress testing, lateral lumbar radiograph to study AAC, echocardiography and biochemical assessments.

Results

The subjects with proportional maximal ergometry workload (WMAX%) less than 50% of the expected values had higher TnT, proBNP, AAC, left ventricular end-diastolic diameter, left ventricular mass index, E/e’ and pulse pressure, and lower global longitudinal strain compared to the better performing patients. TnT (β = − 0.09, p = 0.02), AAC (β = − 1.67, p < 0.0001) and diabetes (β = − 11.7, p < 0.0001) remained significantly associated with WMAX% in the multivariable model. Maximal ergometry workload (in Watts) was similarly associated with TnT and AAC in addition to age, male gender, hemoglobin and diastolic blood pressure in a respective multivariate model.

AAC and TnT showed fair predictive power for WMAX% less than 50% of the expected value with AUCs of 0.70 and 0.75, respectively.

Conclusions

TnT and AAC are independently associated with maximal ergometry stress test workload in patients with advanced CKD.

Trial registration

http://www.ClinicalTrials.gov NCT04223726.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02251-y.

The KNOW-CKD Study: What we have learned about chronic kidney diseases

As the nation’s largest chronic kidney disease (CKD) cohort, the KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD) was established to investigate the clinical course, risk factors for progression, and adverse outcomes of CKD. From 2011 to 2016, the KNOW-CKD recruited 2,238 adult patients with CKD from stage G1 to G5 who were not receiving renal replacement therapy from nine tertiary care hospitals throughout Korea. As of 2019, the KNOW-CKD has published more than 50 articles in the areas of socio-economics, nutrition, quality of life, health-related habits, CKD progression, cardiovascular comorbidity and outcome, anemia, mineral bone disease, biomarker discovery, and international and inter-ethnic comparisons. The KNOW-CKD will eventually offer a prediction model for long-term consequences of CKD, such as the occurrences of end-stage renal disease, cardiovascular disease, and death, thereby enabling the identification and treatment of at-risk populations that require extra medical attention.

Association Between High-Sensitivity Cardiac Troponin T and Echocardiographic Parameters in Chronic Kidney Disease: Results From the KNOW-CKD Cohort Study

Background

It is unclear whether high‐sensitivity troponin T (hs‐TnT) is associated with subclinical cardiac changes in chronic kidney disease (CKD). We evaluated the relationship between hs‐TnT and left ventricular structure and function in a CKD population, according to estimated glomerular filtration rate.

Methods and Results

We analyzed 2017 patients with CKD stages 1 to 5 (predialysis) in the KNOW‐CKD (Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease) cohort. The predictor was hs‐TnT level measured at baseline, and the outcomes were left ventricular hypertrophy (LVH) and systolic and diastolic dysfunction shown by echocardiography at baseline and after 4 years. Participants were categorized into quartiles according to hs‐TnT levels. The associations between quartiles of hs‐TnT and outcomes were assessed using multivariable logistic regression analysis with confounders including demographics, medical history, and laboratory findings. A receiver operating characteristic curve was used to assess the diagnostic power of hs‐TnT for the outcomes as a continuous variable. For subgroup analysis, patients were stratified based on an estimated glomerular filtration rate of 60 mL/min per 1.73 m². Elevated hs‐TnT was associated with LVH and diastolic dysfunction at baseline in an adjusted model but was not associated with systolic dysfunction. These associations remained significant for both estimated glomerular filtration rate subgroups. Receiver operating characteristic curve analysis showed that hs‐TnT as a continuous variable exhibited fair significance for detection of LVH (area under the curve: 0.689) and diastolic dysfunction (area under the curve: 0.744). Multivariable analysis showed that higher hs‐TnT levels at baseline were related to development of LVH but not diastolic dysfunction (n=864).

Conclusions

In CKD patients, hs‐TnT is strongly associated with alterations of left ventricular structure and diastolic dysfunction for both estimated glomerular filtration rate strata. Baseline hs‐TnT levels are predictive of new LVH on follow‐up.