The variation in high sensitive cardiac troponin concentration during haemodialysis treatment is not similar to the biological variation observed in stable end stage renal disease patients

The short-term effect of hemodialysis on the level of high-sensitive cardiac troponin T - A systematic review

INTRODUCTION

Patients with end-stage renal disease (ESRD) have an increased risk of cardiovascular disease, but interpreting cardiac troponin is difficult in this population. The effect of renal replacement therapy (RRT) is important to consider when interpreting serial cardiac troponin T (cTnT) results for patients with ESRD suspected of acute coronary syndrome (ACS). The aim of this systematic review is to answer how low-flux hemodialysis (LF-HD), high-flux hemodialysis (HF-HD), and hemodiafiltration (HDF) affect the blood concentration of high-sensitive cardiac troponin T (hs-cTnT).

METHOD

Several databases were searched and identified records were evaluated independently by two of the authors. Pre- and postdialysis hs-cTnT concentrations together with other relevant data were extracted from the included studies. The quality (potential bias and applicability issues) were assessed for each of the included studies.

RESULTS

The literature search identified 2,540 records and 15 studies were included. The relative pre- to postdialysis change of hs-cTnT varied from -41 to 29%. LF-HD increased the hs-cTnT concentration with relative changes between 2 and 17%. HDF decreased the concentration with relative changes from -41% to -9%. Both increases and decreases were seen for HF-HD (-16% to 12%).

DISCUSSION/CONCLUSION

In this systematic review, we found LF-HD to increase the hs-cTnT concentration and HDF to decrease the concentration. Results for HF-HD and unspecified HD are more heterogeneous. Because of the differences between the included studies, a meta-analysis was not meaningful. This systematic review can help with the assessment of patients with ESRD suspected of ACS in relation to hemodialysis/HDF treatment.

Variability of high-sensitivity cardiac troponin T and I in asymptomatic patients receiving hemodialysis

Variation of high-sensitivity cardiac troponin I and T (hs-cTn) during hemodialysis has been observed. Observational studies demonstrated the increased incidence of adverse cardiovascular events after long compared to short interdialytic intervals. Therefore, we aimed to compare variation of hs-cTnI and hs-cTnT before and after hemodialysis and between short and long interdialytic intervals. We enrolled 200 asymptomatic patients receiving regular hemodialysis. The hs-cTnI and hs-cTnT levels were measured before and after hemodialysis on the day after short and long interdialytic intervals. Mean age was 62.3 ± 14.8 years (Male 55.5%). Prevalence of increased hs-cTnI and hs-cTnT was 34.5% and 99.0%, respectively. The median ± interquartile range of hs-cTnT increased significantly after hemodialysis during short and long interdialytic intervals. However, hs-cTnI level did not increase after hemodialysis during short and long intervals. We found that levels of hs-cTnI and T did not differ between short interdialytic and long interdialytic intervals. We demonstrated higher prevalence of elevated hs-cTnT in patients with regular hemodialysis compared to hs-cTnI. The rise of hs-cTnT was observed immediately after hemodialysis but no significant change of hs-cTnI was noted. Accordingly, hs-cTnI may be preferable as a diagnostic marker in patients with suspected acute myocardial infarction than hs-cTnT.

Short- and long-term biological variation of cardiac troponin I in healthy individuals, and patients with end-stage renal failure requiring haemodialysis or cardiomyopathy

Objectives High-sensitivity (hs) cardiac troponin (cTn) assays can quantitate small fluctuations in cTn concentration. Determining biological variation allows calculation of reference change values (RCV), to define significant changes. We assessed the short- and long-term biological variation of cardiac troponin I (cTnI) in healthy individuals and patients with renal failure requiring haemodialysis or cardiomyopathy. Methods Plasma samples were collected hourly for 4 h and weekly for seven further weeks from 20 healthy individuals, 9 renal failure patients and 20 cardiomyopathy patients. Pre- and post-haemodialysis samples were collected weekly for 7 weeks. Samples were analysed using a hs-cTnI assay (Abbott Alinity ci-series). Within-subject biological variation (CVI), analytical variation (CVA) and between-subject biological variation (CVG) was used to calculate RCVs and index of individuality (II). Results For healthy individuals, CVI, CVA, CVG, RCV and II values were 8.8, 14.0, 43.1, 45.8% and 0.38 respectively for short-term, and 41.4, 14.0, 25.8, 121.0% and 1.69 for long-term. For renal failure patients, these were 2.6, 5.8, 50.5, 17.6% and 0.30 respectively for short-term, and 19.1, 5.8, 11.2, 55.2% and 1.78 for long-term. For cardiomyopathy patients, these were 4.2, 10.0, 65.9, 30.0% and 0.16 respectively for short-term, and 17.5, 10.0, 63.1, 55.8% and 0.32 for long-term. Mean cTnI concentration was lower post-haemodialysis (15.2 vs. 17.8 ng/L, p < 0.0001), with a 16.9% mean relative change. Conclusions The biological variation of cTnI is similar between end-stage renal failure and cardiomyopathy patients, but proportionately greater in well-selected healthy individuals with very low baseline cTnI concentrations.

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.

Coronary artery disease in dialysis patients: evidence synthesis, controversies and proposed management strategies

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality among patients with end-stage renal disease (ESRD). Clustering of traditional atherosclerotic and non-traditional risk factors drive the excess rates of coronary and non-coronary CVD in this population. The incidence, severity and mortality of coronary artery disease (CAD) as well as the number of complications of its therapy is higher in dialysis patients than in non-chronic kidney disease patients. Given the lack of randomized clinical trial evidence in this population, current practice is informed by observational data with a significant potential for bias. Furthermore, guidelines lack any recommendation for these patients or extrapolate them from trials performed in non-dialysis patients. Patients with ESRD are more likely to be asymptomatic, posing a challenge to the correct identification of CAD, which is essential for appropriate risk stratification and management. This may lead to "therapeutic nihilism", which has been associated with worse outcomes. Here, the ERA-EDTA EUDIAL Working Group reviews the diagnostic work-up and therapy of chronic coronary syndromes, unstable angina/non-ST elevation and ST-elevation myocardial infarction in dialysis patients, outlining unclear issues and controversies, discussing recent evidence, and proposing management strategies. Indications of antiplatelet and anticoagulant therapies, percutaneous coronary intervention and coronary artery bypass grafting are discussed. The issue of the interaction between dialysis session and myocardial damage is also addressed.

High sensitivity Troponin-I levels in asymptomatic hemodialysis patients

Reduction in renal clearance and removal by hemodialysis adversely affect the level and utility of high-sensitivity troponin I (hsTnI) for diagnosis of acute myocardial infarction (AMI) in hemodialysis (HD) patients. Furthermore, HD process itself might cause undesirable myocardial injury and enhance post HD hsTnI levels. This comparative cross-sectional study was conducted to compare the hsTnI levels between 100 asymptomatic HD patients and their 107 matched non-chronic kidney disease (CKD) population. The hsTnI levels in HD group were higher than non-CKD group [median (IQR): 54.3 (20.6-152.7) vs. 18 (6.2-66.1) ng/L, p < .001)]. The hsTnI levels reduced after HD process from 54.3 (20.6-152.7) ng/L in pre-HD to 27.1 (12.3-91.4) ng/L in post-HD (p = .015). Of interest, 25% of HD patients had increment of hsTnI after HD and might represent HD-induced myocardial injury. The significant risk factors were high hemoglobin level and high blood flow rate. In conclusion, the baseline hsTnI levels in asymptomatic HD patients were higher than non-CKD population. The dynamic change of hsTnI over time would be essential for the diagnosis of AMI. Certain numbers of asymptomatic HD patients had HD-induced silent myocardial injury and should be aggressively investigated to prevent further cardiovascular mortality.

Revisiting the Biological Variability of Cardiac Troponin: Implications for Clinical Practice

The diagnosis of acute myocardial injury requires a rise and/or fall of cardiac troponin (cTn) on serial testing, with at least one concentration above the 99th percentile value of a normal reference population according to the recently published Fourth Universal Definition of Myocardial Infarction.1 However, the magnitude of change in cTn that constitutes a significant rise and/or fall was again not specified in detail. High-sensitivity cardiac troponin (hs-cTn) assays can measure ten-fold lower concentrations of cTn with more precision than older assays, and can accurately quantify cTn in more than 50% of healthy individuals with a coefficient of variation of less than 10% at the 99th percentile. These hs-cTn assays are also able to detect the normal variations in cTn results that are due to biological variability. Understanding and quantifying the normal variations in cTn is important as this would allow significant changes to be better defined. Numerous studies have sought to investigate the biological variability of cTn over the last ten years. Such studies are usually conducted in healthy individuals, however individuals with chronic cardiac disease or chronic renal failure have also been examined. These studies have yielded varying results in regards to significant change values for cTn. In light of the recent redefinition for myocardial infarction, the purpose of this mini-review is to revisit the biological variability of cTn. In particular, we outline concepts for determining a significant change value, review the results of previous studies on the biological variation of cTn and discuss potential considerations for clinical practice.

Can High-Sensitivity Troponins Predict Future Hypertension? A Systematic Literature Review

Hypertension (HT) is associated with cardiovascular events and increased mortality, and identification of persons at risk in due time is therefore important. Finding a biomarker to identify those at risk will enable early preventive treatment, and high-sensitivity cardiac troponin (hs-cTn) seems to be a highly relevant candidate. To gather the existing knowledge on the association between hs-cTn and future HT, a systematic literature review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) reporting guidelines and using the PICOS system. Medline was searched until August 2018. Of 45 extracted papers, eleven papers were eligible for the study. None were randomized controlled trials. Three studies assessed hs-cTnI, eight studies assessed hs-cTnT. All studies found statistically significant associations between hs-cTn concentrations and future HT, but the studies included different types of blood pressure (diastolic, systolic, diurnal). Due to differences in troponin assay construction and test capability, a direct comparison of test performance in terms of specificity, sensitivity and predictive values was not possible, and a specific hs-cTn cutoff value for HT prediction could therefore not be defined. Furthermore, a number of conditions known to affect troponin concentrations (e.g. gender, renal function, and co-morbidities) were not sufficiently studied. All retrieved studies found significant associations between hs-cTn concentrations and future HT; although the findings are promising, the studies were too heterogeneous, and many conditions affecting troponin concentrations needs investigation at these low concentrations before hs-cTn can be considered a useful HT predictor.