Association of Thrombotic and Fibrinolytic Factors with Severity of Culprit Lesion in Patients with Acute Coronary Syndromes Without ST Elevation:

D-dimers are associated with coronary artery disease severity assessed using Syntax and Syntax II scores in patients with ST elevation myocardial infarction

INTRODUCTION AND OBJECTIVES

D-dimers are a determinant of hypercoagulable state and have been found to be related to acute coronary syndromes. We aimed to establish the association between increased D-dimer levels and coronary artery disease (CAD) severity using SYNTAX Score (SS) II in patients with ST elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI).

METHODS

This retrospective study included 300 consecutive patients (81.7% males, mean age 55±12 years) with STEMI who underwent a primary PCI. Patients were divided into two groups according to their median SSII [SSII<25 as a low group (n=151) and SSII≥25 as a high group (n=149)]. Blood samples for D-dimers and the other biochemical parameters were obtained from each patient at admission.

RESULTS

When compared with the low SSII group, frequency of female gender, no-reflow phenomenon, D-dimer levels, thrombus score, creatine kinase MB and troponin were significantly higher, whereas left ventricular ejection fraction (LVEF) and glomerular filtration rate (GFR) were lower in the high SSII group (p<0.05, for all). D-dimer levels, thrombus score, LVEF, GFR and no-reflow phenomenon were independent predictors of CAD severity (p<0.05, for all). Receiver operating characteristic curve analysis showed that the D-dimer cut-off value for predicting the severity of CAD was 0.26 μg/ml (69.8% sensitivity and 65.6% specificity, p<0.001).

CONCLUSION

Increased D-dimer levels are associated with the severity of CAD based on Syntax Score II, in patients with STEMI who successfully underwent revascularization with a primary PCI.

Biomarkers of coagulation and fibrinolysis in acute myocardial infarction: a joint position paper of the Association for Acute CardioVascular Care and the European Society of Cardiology Working Group on Thrombosis

The formation of a thrombus in an epicardial artery may result in an acute myocardial infarction (AMI). Despite major advances in acute treatment using network approaches to allocate patients to timely reperfusion and optimal antithrombotic treatment, patients remain at high risk for thrombotic complications. Ongoing activation of the coagulation system as well as thrombin-mediated platelet activation may both play a crucial role in this context. Whether measurement of circulating biomarkers of coagulation and fibrinolysis could be useful for risk stratification in secondary prevention is currently not fully understood. In addition, measurement of such biomarkers could be helpful to identify thrombus formation as the leading mechanism for AMI. The introduction of biomarkers of myocardial injury such as high-sensitivity cardiac troponins made rule-out of AMI even more precise. However, elevated markers of myocardial injury cannot provide proof of a type 1 AMI, let alone thrombus formation. The combined measurement of markers of myocardial injury with biomarkers reflecting ongoing thrombus formation might be helpful for the fast and correct diagnosis of an atherothrombotic type 1 AMI. This position paper gives an overview of the current knowledge and possible role of biomarkers of coagulation and fibrinolysis for the diagnosis of AMI, risk stratification, and individualized treatment strategies in patients with AMI.

The Value of d-Dimer Level in Predicting Contrast-Induced Acute Kidney Injury in Patients With Acute ST-Segment Elevation Myocardial Infarction After PCI

Contrast-induced acute kidney injury (CI-AKI) is a serious complication of percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI). Early identification of high-risk patients has an essential role in preventing CI-AKI. This study was designed to evaluate the predictive value of d-dimer, a marker of thrombosis and hypercoagulable state, for CI-AKI and prognosis in patients with STEMI. We included 400 patients with STEMI who underwent PCI. The patients were subdivided into 4 groups according to d-dimer level using the 4-quantile method. Contrast-induced acute kidney injury occurred in 66 (16.5%) patients. The incidence of CI-AKI in the highest quartile of the d-dimer groups (29.0%) was higher than that in the other 3 groups. Multivariable logistic regression showed that a low d-dimer level was significantly associated with a decreased risk of CI-AKI independent of confounding factors, with an odds ratio (OR) of 0.487 (95% CI: 0.178-0.931, P = 0.041) for those in the first quartile compared with those in the highest quartile. Age (OR: 1.047, 95% CI: 1.003-1.092), diabetes mellitus (OR: 5.896, 95% CI: 2.496-13.927), anemia (OR: 3.488, 95% CI: 1.308-9.306), and total bilirubin (OR: 0.946, 95% CI: 0.904-0.992) were independent predictors of CI-AKI. The incidence of major adverse cardiovascular and cerebral events and all-cause mortality within 30 days, 6 months, and 1 year after PCI in the highest quartile of the d-dimer groups were higher than those in the other 3 groups. In conclusion, increasing d-dimer levels were independently associated with the incidence of CI-AKI and adverse outcomes in patients with STEMI after PCI.

Cell-Free circulating DNA: a new biomarker for the acute coronary syndrome

BACKGROUND

In recent studies, concentrations of cell-free circulating DNA (cf-DNA) have been correlated with clinical characteristics and prognosis in several diseases. The relationship between cf-DNA concentrations and the acute coronary syndrome (ACS) remains unknown. Moreover, no data are available for the detection cf-DNA in ACS by a branched DNA (bDNA)-based Alu assay. The aim of the present study was to investigate cf-DNA concentrations in ACS and their relationship with clinical features.

METHODS

Plasma cf-DNA concentrations of 137 ACS patients at diagnosis, of 60 healthy individuals and of 13 patients with stable angina (SA) were determined using a bDNA-based Alu assay.

RESULTS

ACS patients (median 2,285.0, interquartile range 916.4-4,857.3 ng/ml), especially in ST-segment elevation myocardial infarction patients (median 5,745.4, interquartile range 4,013.5-8,643.9 ng/ml), showed a significant increase in plasma cf-DNA concentrations compared with controls (healthy controls: median 118.3, interquartile range 81.1-221.1 ng/ml; SA patients: median 202.3, interquartile range 112.7-256.1 ng/ml) using a bDNA-based Alu assay. Moreover, we found positive correlations between cf-DNA and Gensini scoring and GRACE (Global Registry of Acute Coronary Events) scoring in ACS.

CONCLUSION

cf-DNA may be a valuable marker for diagnosing and predicting the severity of coronary artery lesions and risk stratification in ACS.

Characterization of coronary fibrin thrombus in patients with acute coronary syndrome using dye-staining angioscopy

OBJECTIVE

Because fibrin is transparent and almost invisible by any conventional imaging methodologies, clinical examinations of coronary fibrin thrombus have been ignored, and little is known about its role in the genesis of acute coronary syndrome (ACS). The present study was performed to visualize coronary fibrin thrombus and to examine its role in ACS.

METHODS AND RESULTS

Dye-staining coronary angioscopy using Evans blue dye, which selectively stains fibrin blue but does not stain blood corpuscles, was performed for observation of globular coronary thrombi in 111 ACS patients. The thrombi were aspirated for histological examination. The thrombi were classified by visual appearance into 8 transparent, 3 light-red, 2 frosty glass-like and membranous, 32 white, 8 brown, 34 red, and 19 red-and-white in a mosaic pattern. Transparent thrombi that were not visible by conventional angioscopy were visualized as a blue structure by dye-staining angioscopy, and they were observed in patients with unstable angina (UA) and non-ST elevation myocardial infarction (NSTEMI). The thrombi caused total or subtotal coronary occlusion. The aspirated thrombi were composed of fibrin alone by histology. Fibrin-rich thrombi were visualized using dye-staining angioscopy in 60% of 50 patients with UA+NSTEMI and in 29% of 61 patients with ST-elevation myocardial infarction. By histology of the aspirated thrombi, fibrin-rich thrombi were observed in 71% of 33 patients with UA+NSTEMI and in 28% of 35 patients with ST-elevation myocardial infarction.

CONCLUSION

Fibrin-rich coronary thrombi were frequently observed by both dye-staining angioscopy and histology in ACS patients. Rarely, fibrin itself formed a globular thrombus and caused coronary occlusion.

Characterization of the yeast tricalbins: membrane-bound multi-C2-domain proteins that form complexes involved in membrane trafficking

In a survey of yeast genomic sequences encoding calcium- and phospholipid-binding C2 domains, three homologous genes were identified that encode proteins that each have three C2 domains and an apparent transmembrane domain near the N terminus. The name tricalbins is suggested for these proteins, corresponding to the open reading frames YOR086c (TCB1), YNL087w (TCB2), and YML072c (TCB3). An antiserum was raised against the C-terminal portion of tricalbin 2 and used on Western blots to demonstrate that the corresponding protein is expressed in yeast and appears as a high-molecular-weight band at 130 kDa with smaller fragments at 39 kDa and 46 kDa. A fusion protein consisting of full length tricalbin 2 fused to the green fluorescent protein was expressed in cells and found to traffic from the cell surface to intracellular vesicles near the vacuole. A two-hybrid interaction screen with the C-terminal portion of tricalbin 2 indicated that tricalbin 2 binds the C-terminal portions of tricalbins 1 and 3 suggesting that the tricalbins may form heterodimers in vivo. Tricalbin 2 also interacted with the activation domain of the pleiotropic drug resistance transcription factor Pdr1p. Combinatorial disruptions of the tricalbin genes revealed that tcb2 single mutants or tcb1, tcb3 double mutants have an altered vacuole morphology and are hypersensitive to cycloheximide. A screen for single-copy suppressors of the cycloheximide sensitivity of tricalbin mutants yielded RSP5, which encodes a C2-domain-containing, ubiquitin-conjugating ligase essential for receptor-mediated and fluid phase endocytosis. The results suggest that the tricalbins function as multimers in membrane-trafficking events and may provide insights into the roles of multi-C2-domain proteins, such as the synaptotagmins, in other organisms.