The role of cardiac troponin-I (cTnI) in risk stratification of patients with unstable coronary artery disease

Relation of circulating lncRNA GAS5 and miR-21 with biochemical indexes, stenosis severity, and inflammatory cytokines in coronary heart disease patients

Background

Long noncoding RNA GAS5 (lnc‐GAS5) and its target microRNA‐21 (miR‐21) regulate blood lipid, macrophages, Th cells, vascular smooth muscle cells to participate in atherosclerosis, and related coronary heart disease (CHD). The study aimed to further explore the linkage of their circulating expressions with common biochemical indexes, stenosis severity and inflammatory cytokines in CHD patients.

Methods

Ninety‐eight CHD patients and 100 controls confirmed by coronary angiography were enrolled. Plasma samples were collected for lnc‐GAS5 and miR‐21 detection by reverse transcription‐quantitative polymerase chain reaction and inflammatory cytokines determination by enzyme‐linked immunosorbent assay.

Results

Lnc‐GAS5 was increased in CHD patients compared with controls (2.270 (interquartile range [IQR]: 1.676–3.389) vs. 0.999 ([IQR: 0.602–1.409], p < 0.001), whereas miR‐21 showed opposite tread (0.442 [IQR: 0.318–0.698] vs. 0.997 [IQR: 0.774–1.368], p < 0.001). In aspect of their intercorrelation, lnc‐GAS5 negatively linked with miR‐21 in CHD patients (p < 0.001) instead of controls (p = 0.211). Interestingly, among the common biochemical indexes, lnc‐GAS5 related to decreased high‐density lipoprotein cholesterol (p = 0.008) and increased C‐reactive protein (CRP) (p < 0.001), while miR‐21 correlated with lower total cholesterol (p = 0.024) and CRP (p < 0.001) in CHD patients. As stenosis degree, lnc‐GAS5 positively correlated with Gensini score (p < 0.001), but miR‐21 exhibited negative association (p = 0.003) in CHD patients. In terms of inflammatory cytokines, lnc‐GAS5 positively related to tumor necrosis factor α (TNF‐α) and interleukin (IL)‐17A, while miR‐21 negatively linked with TNF‐α, IL‐1β, IL‐6, and IL‐17 in CHD patients (all p < 0.05).

Conclusion

Circulating lnc‐GAS5 and its target miR‐21 exhibit potency to serve as biomarkers for CHD management.

An ultrasensitive electrochemical sensing platform for the detection of cTnI based on aptamer recognition and signal amplification assisted by TdT

We have developed an ultrasensitive and highly specific electrochemical sensing platform for the detection of cardiac troponin I (cTnI), a recognized biomarker for the diagnosis of acute myocardial infarction (AMI) and related cardiovascular diseases (CVDs). This strategy is based on the assists of terminal deoxynucleotidyl transferase (TdT)-mediated signal amplification and the specific recognition between cTnI and the aptamer of cTnI. In this experiment, we prepared a gold electrode that modified with probe 2 (P2), in the presence of cTnI, the aptamer of cTnI that in probe 1 (P1)/aptamer complexes bond with cTnI specifically and release the free P1. P1 would bind with P2, resulting in the formation of 3'-OH of DNA. In the presence of terminal deoxynucleotidyl transferase (TdT) and dTTP, TdT mediated P1 to extend and formed the structure of poly T. Methylene blue (MB)-poly A hybridized with the extended poly T and generated an electrochemical signal. The detection limit can be as low as 40 pg mL-1. This sensor was also successfully applied to the detection of cTnI in numerous spiked biological samples, and it can be a great reference for the clinical diagnosis, prognosis, and treatment of CVDs and AMI.

Correlations of Changes in Brain Natriuretic Peptide (BNP) and Cardiac Troponin I (cTnI) with Levels of C-Reactive Protein (CRP) and TNF-α in Pediatric Patients with Sepsis

Background

This study investigated the changes in plasma brain natriuretic peptide (BNP) and cardiac troponin I (cTnI) levels in pediatric patients with sepsis, and explored their relationships with serum inflammatory factors in pediatric patients.

Material/Methods

A total of 120 pediatric patients with sepsis admitted to and treated at our hospital from 2013 to 2017 were divided into 4 groups: a systemic inflammatory response syndrome (SIRS) group (n=28), a sepsis group (n=35), a severe sepsis group (n=27), and a septic shock group (n=30). Plasma BNP, cTnI, and creatine kinase-MB (CK-MB) levels in pediatric patients in the 4 groups were measured, and the correlations of BNP and cTnI with plasma inflammatory factors C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-α) were investigated.

Results

The plasma BNP and cTnI levels in pediatric patients with sepsis were significantly higher than those in the SIRS group (p<0.05). After hospitalization and treatment, levels of BNP and cTnI in pediatric patients were decreased. The concentrations of BNP and cTnI were correlated with CRP level (r=0.88 and 0.88, respectively). The associations (r value) of BNP and cTnI with TNF-α levels were 0.35 and 0.48, respectively.

Conclusions

The levels of plasma BNP and cTnI are associated with the severity of sepsis in pediatric patients, and were positively correlated with CRP and TNF-α levels, which provides a novel strategy for the early diagnosis and evaluation of sepsis in pediatric patients.

Heart-type fatty acid binding protein (H-FABP) as a biomarker for acute myocardial injury and long-term post-ischemic prognosis

Acute myocardial infarction (AMI) is a life-threatening event. Even with timely treatment, acute ischemic myocardial injury and ensuing ischemia reperfusion injury (IRI) can still be difficult issues to tackle. Apart from radiological and other auxiliary examinations, laboratory tests of applicable cardiac biomarkers are also necessary for early diagnosis and close monitoring of this disorder. Heart-type fatty acid binding protein (H-FABP), which mainly exists inside cardiomyocytes, has recently emerged as a potentially promising biomarker for myocardial injury. In this review we discuss the sensitivity and specificity of H-FABP in the assessment of myocardial injury and IRI, especially in the early stage, and its long-term prognostic value in comparison with other commonly used cardiac biomarkers, including myoglobin (Mb), cardiac troponin I (cTnI), creatine kinase MB (CK-MB), C-reactive protein (CRP), glycogen phosphorylase isoenzyme BB (GPBB), and high-sensitivity cardiac troponin T (hs-cTnT). The potential and value of combined application of H-FABP with other biomarkers are also discussed. Finally, the prospect of H-FABP is summarized; several technical issues are discussed to facilitate wider application of H-FABP in clinical practice.

Peripheral blood miRNAs as a biomarker for chronic cardiovascular diseases. Sci Rep. 2014;4:5026. [PMID: 24848278 PMCID: PMC4052773 DOI: 10.1038/srep05026]

Vascular diseases are the most prevalent diseases worldwide. This study intended to analyze peripheral blood miRNA levels and their correlation with NT-pro-BNP and cTN-I in patients with atherosclerosis or pre-atherosclerotic conditions to build a dynamic correlation between vascular diseases and their biomarkers. Serum NT-pro-BNP and cTN-I levels were measured by their respective ELISA kits. The miRNA levels were assayed by quantitative PCR. Unique miRNA signatures were identified for both atherosclerosis and pre-atherosclerosis. The levels of miR-92a, 126, 130a, 222, and 370 levels were decreased in the peripheral blood of pre-atherosclerotic subjects. In atherosclerosis, miR-21, 122, 130a, and 211 were significantly increased whereas miR-92a, 126, and 222 were markedly decreased. Serum levels of NT-pro-BNP and cTN-I correlated with each other and increased with the progression of atherosclerosis. Moreover, the levels of cTN-I and NT-pro-BNP were positively correlated with miR-21 and negatively correlated with miR-126. Integrating specific pattern of miRNA levels with NT-pro-BNP and/or cardiac troponin may improve the diagnosis of cardiovascular diseases.

Cardiac amyloidosis presenting with elevations of cardiac troponin I and angina pectoris

We present the case of a 43-year-old male who was initially evaluated for angina pectoris and dyspnea. His CK, CK-MB, and cTnI were all elevated following a blood transfusion and he underwent coronary arteriography, which demonstrated no luminal obstructions. After several months, he was transferred to Mayo Clinic where diagnoses of fulminant cardiac amyloidosis and systemic multiple myeloma were established. The cTnI remained elevated despite normalization of the CK and CK-MB. Despite aggressive treatment, the patient died. Postmortem analysis demonstrated amyloid cardiac deposition including involvement of the coronary microvasculature. Electron microscopy revealed myocyte compression injury from amyloid infiltration. We believe this is the first report of elevated troponin I in a patient with cardiac amyloidosis. The electron microscopy in our case confirms cardiac damage as the mechanism for cTnI elevation. This observation strengthens our knowledge about the specificity of cTnI for the detection of cardiac injury.

Cardiac troponin I predicts short-term mortality in vascular surgery patients

BACKGROUND

Cardiac troponin I (cTnI) is a highly sensitive and specific marker for myocardial injury that predicts outcomes in patients with acute coronary syndromes. Cardiovascular complications are the leading cause of morbidity and mortality in patients who have undergone vascular surgery. However, postoperative surveillance with cardiac enzymes is not routinely performed in these patients. We evaluated the association between postoperative cTnI levels and 6-month mortality and perioperative myocardial infarction (MI) after vascular surgery.

METHODS AND RESULTS

Two hundred twenty-nine patients having aortic or infrainguinal vascular surgery or lower extremity amputation were included in this study. Blood samples were analyzed for cTnI immediately after surgery and the mornings of postoperative days 1, 2, and 3. An elevated cTnI was defined as serum concentrations >1.5 ng/mL in any of the 4 samples. Twenty-eight patients (12%) had postoperative cTnI >1.5 ng/mL, which was associated with a 6-fold increased risk of 6-month mortality (adjusted OR, 5.9; 95% CI, 1.6 to 22.4) and a 27-fold increased risk of MI (OR, 27.1; 95% CI, 5.2 to 142.7). Furthermore, we observed a dose-response relation between cTnI concentration and mortality. Patients with cTnI >3.0 ng/mL had a significantly greater risk of death compared with patients with levels < or =0.35 ng/mL (OR, 4.9; 95% CI, 1.3 to 19.0).

CONCLUSIONS

Routine postoperative surveillance for cTnI is useful for identifying patients who have undergone vascular surgery who have an increased risk for short-term mortality and perioperative MI. Further research is needed to determine whether intervention in these patients can improve outcome.

Determination of cardiac troponin I forms in the blood of patients with unstable angina pectoris

OBJECTIVE

To determine the predominant form in which cardiac troponin I circulates in the bloodstream of unstable angina patients.

DESIGN AND METHODS

The cardiac troponin I forms released in the bloodstream of 25 patients suffering from unstable angina were examined by using three immunoenzymatic assays: the total cTnI assay for detection of free and complexed cTnI, the IC-TIC assay for detection of the IC and TIC troponin complexes, and the IT-TIC assay for detection of the IT and TIC troponin complexes.

RESULTS

Approximately 60% of patients with unstable angina had at least one positive value in the total cTnI assay or in the IC-TIC assay. Our results demonstrated that the predominant cardiac troponin I form circulating in the bloodstream of patients with unstable angina was the IC complex. Free cTnI, IT, and/or TIC forms were seldom found, the frequency of IT and/or TIC complexes being higher than that observed previously in patients with acute myocardial infarction.

CONCLUSIONS

The release pattern of cTnI in patients suffering from unstable angina is similar to that previously observed in patients with acute myocardial infarction, i.e., a predominance of the IC complex.

Clinical Efficacy of Three Assays for Cardiac Troponin I for Risk Stratification in Acute Coronary Syndromes: A Thrombolysis In Myocardial Infarction (TIMI) 11B Substudy

Background: Significant analytic variability exists between the multiple assays for cardiac troponin I (cTnI) approved for clinical use. Until adequate cTnI standardization is possible, an evidence-based approach evaluating each assay at specific thresholds appears warranted.

Methods: We examined the efficacy of three cTnI assays for predicting death, myocardial infarction (MI), or the composite of death, MI, or urgent revascularization at 43 days among patients with non-ST-elevation acute coronary syndromes enrolled in the Thrombolysis In Myocardial Infarction (TIMI) 11B study.

Results: Six hundred eighty-one patients with serum samples obtained at baseline and/or 12–24 h had cTnI determined using all three assays. Baseline cTnI was ≥0.1 μg/L for 368, 395, and 418 patients with the Bayer Immuno 1TM, ACS:180®, and Dimension® RxL assays, respectively. Correlation coefficients for the RxL with the ACS:180 and Bayer Immuno 1 results were 0.89 (P = 0.0001) and 0.87 (P = 0.0001), with a coefficient of 0.92 (P = 0.0001) for the ACS:180 and Bayer Immuno 1 assays. Patients with cTnI ≥0.1 μg/L were at increased risk for death or MI by 43 days (relative risk, 2.2–3.0; P &lt;0.0006), regardless of the assay used. This prognostic capacity persisted among those with creatine kinase MB isoenzyme concentrations within the reference interval. Moreover, cTnI was the strongest multivariate predictor of death, MI, or urgent revascularization with adjusted odds ratios of 2.1–2.9 (P &lt;0.0006).

Conclusion: This study demonstrates the prognostic efficacy of three independently developed cTnI assays at a threshold of 0.1 μg/L for the prediction of adverse clinical outcomes among patients with non-ST-elevation acute coronary syndromes.