Discordant Cardiac Biomarkers: Frequency and Outcomes in Emergency Department Patients With Chest Pain

Interventional cardiac catheterization predictors at Al-Arabi heart Center in Palestine in 2017

Background

Cardiac catheterization is performed for both therapeutic and diagnostic reasons, in which the outcome may vary from only medical treatment to the need of percutaneous coronary intervention and ending with coronary artery bypass graft. The primary goal of this study was to determine predictors of revascularization.

Methods

A retrospective cohort study was conducted on data collected from records of patients who underwent cardiac catheterization at Al-Arabi Heart Center in Palestine in 2017. Multivariate logistic regression analysis was carried out to assess the association of sociodemographic and pre-catheterization clinical predictors with revascularization.

Results

A total of 1550 patients were included in the study. The participants mean age was 58 with a SD of 11.7 years, 73.6% were males. 50.2% of patients who underwent an interventional cardiac catheterization tested negative for troponin on presentation. Multivariate logistic regression showed Troponin (RR = 4.5), Age (RR = 1.0), Female gender (RR = 0.4) previous catheterization (RR = 2.0), and existence of diabetes as significant predictors for revascularization. The correlation between ECG on presentation and the subsequent need for an interventional cardiac catheterization was significant only in case of ST-Elevation (RR = 1.5), and T wave inversion (RR = 1.6). CK-MB, Hypertension and ECG with ST-depression were not significant predictors.

Conclusion

This study assessed revascularization predictors in addition to characteristics and outcomes of patients who have undergone cardiac catheterization. The results showed the especially high predictive value of troponin in determining the need for revascularization which outweighed the importance of ECG findings on presentation in making clinical decision regarding catheterization.

Association of Biomarker Clusters With Cardiac Phenotypes and Mortality in Patients With HIV Infection

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Background:

Although individual cardiac biomarkers are associated with heart failure risk and all-cause mortality in HIV-infected individuals, their combined use for prediction has not been well studied.

Methods and Results:

Unsupervised k-means cluster analysis was performed blinded to the study outcomes in 332 HIV-infected participants on 8 biomarkers: ST2, NT-proBNP (N-terminal pro-B-type natriuretic peptide), hsCRP (high-sensitivity C-reactive protein), GDF-15 (growth differentiation factor 15), cystatin C, IL-6 (interleukin-6), D-dimer, and troponin. We evaluated cross-sectional associations of each cluster with diastolic dysfunction, pulmonary hypertension (defined as echocardiographic pulmonary artery systolic pressure ≥35 mm Hg), and longitudinal associations with all-cause mortality. The biomarker-derived clusters partitioned subjects into 3 groups. Cluster 3 (n=103) had higher levels of CRP, IL-6, and D-dimer (inflammatory phenotype). Cluster 2 (n=86) displayed elevated levels of ST2, NT-proBNP, and GDF-15 (cardiac phenotype). Cluster 1 (n=143) had lower levels of both phenotype-associated biomarkers. After multivariable adjustment for traditional and HIV-related risk factors, cluster 3 was associated with a 51% increased risk of diastolic dysfunction (95% confidence interval, 1.12–2.02), and cluster 2 was associated with a 67% increased risk of pulmonary hypertension (95% confidence interval, 1.04–2.68), relative to cluster 1. Over a median 6.9-year follow-up, 48 deaths occurred. Cluster 3 was independently associated with a 3.3-fold higher risk of mortality relative to cluster 1 (95% confidence interval, 1.3–8.1), and cluster 2 had a 3.1-fold increased risk (95% confidence interval, 1.1–8.4), even after controlling for diastolic dysfunction, pulmonary hypertension, left ventricular mass, and ejection fraction.

Conclusions:

Serum biomarkers can be used to classify HIV-infected individuals into separate clusters for differentiating cardiopulmonary structural and functional abnormalities and can predict mortality independent of these structural and functional measures.

Discordant creatine kinase and cardiac troponin T in the workup of acute coronary syndrome

A 55-year-old man presented to the emergency department (ED) following 2 episodes of typical cardiac chest pain and nonspecific electrocardiogram findings. His serial cardiac marker assays revealed an elevated total creatine kinase (CK) and 2 negative cardiac troponin levels. Because of a high clinical suspicion of acute coronary syndrome, a total creatine kinase MB mass was obtained and found to be elevated. Subsequent cardiac angiography demonstrated a significantly flow-limiting coronary artery lesion, and stenting was performed. This case demonstrates that simultaneous CK and troponin measurements may have utility in selected ED patients with chest pain. The interpretation of discordant CK and troponin levels is discussed.

Utility of salivary biomarkers for demonstrating acute myocardial infarction

The comparative utility of serum and saliva as diagnostic fluids for identifying biomarkers of acute myocardial infarction (AMI) was investigated. The goal was to determine if salivary biomarkers could facilitate a screening diagnosis of AMI, especially in cases of non-ST elevation MI (NSTEMI), since these cases are not readily identified by electrocardiogram (ECG). Serum and unstimulated whole saliva (UWS) collected from 92 AMI patients within 48 hours of chest pain onset and 105 asymptomatic healthy control individuals were assayed for 13 proteins relevant to cardiovascular disease, by Beadlyte technology (Luminex(®)) and enzyme immunoassays. Data were analyzed with concentration cut-points, ECG findings, logistic regression (LR) (adjusted for matching for age, gender, race, smoking, number of teeth, and oral health status), and classification and regression tree (CART) analysis. A sensitivity analysis was conducted by repetition of the CART analysis in 58 cases and 58 controls, each matched by age and gender. Serum biomarkers demonstrated AMI sensitivity and specificity superior to that of saliva, as determined by LR and CART. The predominant discriminators in serum by LR were troponin I (TnI), B-type natriuretic peptide (BNP), and creatine kinase-MB (CK-MB), and TnI and BNP by CART. In saliva, LR identified C-reactive protein (CRP) as the biomarker most predictive of AMI. A combination of smoking tobacco, UWS CRP, CK-MB, sCD40 ligand, gender, and number of teeth identified AMI in the CART decision trees. When ECG findings, salivary biomarkers, and confounders were included, AMI was predicted with 80.0% sensitivity and 100% specificity. These analyses support the potential utility of salivary biomarker measurements used with ECG for the identification of AMI. Thus, saliva-based tests may provide additional diagnostic screening information in the clinical course for patients suspected of having an AMI.

Elevated CK-MB with a normal troponin does not predict 30-day adverse cardiac events in emergency department chest pain observation unit patients

BACKGROUND

Prior studies indicate that an elevated creatinine kinase (CK)-MB imparts poor prognosis in patients with acute coronary syndrome despite a normal troponin. Its prognosis in the undifferentiated chest pain observation unit (CPU) population remains undefined.

OBJECTIVE

To compare rates and predictors of 30-day adverse cardiac events in 2 cohorts (CK ±/MB+ vs. normal [CK ±/MB-]) in low-moderate-risk CPU patients.

METHODS

Consecutive CPU patients were followed in a retrospective cohort study for primary outcome (acute coronary syndrome, percutaneous transluminal coronary angioplasty, coronary artery bypass graft, abnormal stress test, cardiac hospitalization, or death within 30 days) by using standardized chart reviews and national death registry. Exclusions were: those aged 30 years or younger, positive troponin, ischemic electrocardiogram, hemodynamic instability, heart failure, or dialysis.

RESULTS

Between January 2006 and April 2009, 2979 patients were eligible, of which 350 excluded and 2629 analyzed. MB+ compared with normal patients were more likely to be: older (mean, 53.4 ± 14 vs. 51.5 ± 12 years; P = 0.04); male (71% vs. 40%; P = 0.01); renal insufficient (5% vs. 2%; P = 0.01); hypertensive (50% vs. 44%; P = 0.04); dyslipidemic (44% vs. 33%; P = 0.01) obese (55% vs. 43%; P = 0.01); and with known coronary artery disease (14% vs. 5%; P < 0.01). Composite adverse events were 213 (8%) and did not significantly differ for either initial MB+ vs. normal (9.1%, 8.0%; odds ratio, 1.1, 0.7-1.9) or serial MB+ vs. normal (7.5%, 7.4%; odds ratio, 1.0, 0.5-1.8). In a multiple logistic regression model, male sex, diabetes, and prior CAD predicted adverse events, whereas CK-MB along with race, hypertension, smoking, dyslipidemia, family history, and obesity did not.

CONCLUSIONS

Elevated CK-MB does not add value to serial troponin testing in low-moderate-risk CPU patients.

Isolated creatine kinase-MB rise with normal cardiac troponins: a strange occurrence with difficult interpretation

A 37-year-old man is admitted to the hospital for retrosternal chest pain lasting more than 30  min and nonspecific ECG findings. Serial assays of cardiac biomarkers reveal an isolated elevation of creatine kinase-MB and negative troponin levels. A coronary angiography shows normal vessels in the presence of a Thrombolysis in Myocardial Infarction (TIMI) 2 flow. How should this patient be managed and treated? Is it a myocardial infarction? We here provide a review of the relevant literature and suggest that such a strange condition, for which several explanations are possible, involves a worse prognosis than for normal creatine kinase-MB and troponins.

Outcomes associated with small changes in normal-range cardiac markers

INTRODUCTION

Troponin concentrations rising above an institutional cutpoint are used to define acute myocardial necrosis, yet it is uncertain what outcomes are associated with fluctuations in troponin that do not exceed this level. We evaluate the association between troponin fluctuations below an institutional upper limit of normal and acute coronary syndrome (ACS).

MATERIALS AND METHODS

This was a post hoc analysis of the Internet tracking registry of ACS (i*trACS), which describes patients presenting to emergency departments (EDs) with suspected ACS across the spectrum of risk. Patients were included in this registry if they were at least 18 years old and had suspected ACS at the time of their ED visit. Inclusions in this analysis required that patients had at least 1 cardiac marker (creatine kinase-MB [CK-MB], troponin T, or troponin I) drawn twice within 6 hours of presentation, with both measures being below the institution's upper limit of normal. A marker change was defined as either an increase or decrease that exceeded 15% of the institutional upper limit of normal. Acute coronary syndrome was defined as a positive stress test, documented myocardial infarction, coronary revascularization, or death within 30 days of their ED admission.

RESULTS

Of 17,713 patient visits, 2162 met inclusion and exclusion criteria. There were 1872 patient visits with 2 troponin results and 1312 with 2 CK-MB results. Patient visits with increasing troponin had increased odds of ACS compared with those with stable troponin levels (odds ratio, 3.6; 95% confidence interval, 1.4-9.2). Changing CK-MB and decreasing troponin were not associated with increased odds of ACS.

CONCLUSIONS

Small increases in troponin concentration below the upper limit of normal are associated with increased odds of ACS.