Micro-CT-Based Quantification of Extracted Thrombus Burden Characteristics and Association With Angiographic Outcomes in Patients With ST-Elevation Myocardial Infarction: The QUEST-STEMI Study

Background: Angiographic detection of thrombus in STEMI is associated with adverse outcomes. However, routine thrombus aspiration failed to demonstrate the anticipated benefit. Hence, management of high coronary thrombus burden remains challenging. We sought to assess for the first time extracted thrombotic material characteristics utilizing micro-computed tomography (micro-CT). Methods: One hundred thirteen STEMI patients undergoing thrombus aspiration were enrolled. Micro-CT was undertaken to quantify retrieved thrombus volume, surface, and density. Correlation of these indices with angiographic and electrocardiographic outcomes was performed. Results: Mean aspirated thrombus volume, surface, and density (±standard deviation) were 15.71 ± 20.10 mm³, 302.89 ± 692.54 mm², and 3139.04 ± 901.88 Hounsfield units, respectively. Aspirated volume and surface were significantly higher (p < 0.001) in patients with higher angiographic thrombus burden. After multivariable analysis, independent predictors for thrombus volume were reference vessel diameter (RVD) (p = 0.011), right coronary artery (RCA) (p = 0.039), and smoking (p = 0.027), whereas RVD (p = 0.018) and RCA (p = 0.019) were predictive for thrombus surface. Thrombus volume and surface were independently associated with distal embolization (p = 0.007 and p = 0.028, respectively), no-reflow phenomenon (p = 0.002 and p = 0.006, respectively), and angiographically evident residual thrombus (p = 0.007 and p = 0.002, respectively). Higher thrombus density was correlated with worse pre-procedural TIMI flow (p < 0.001). Patients with higher aspirated volume and surface developed less ST resolution (p = 0.042 and p = 0.023, respectively). Conclusions: Angiographic outcomes linked with worse prognosis were more frequent among patients with larger extracted thrombus. Despite retrieving larger thrombus load in these patients, current thrombectomy devices fail to deal with thrombotic material adequately. Further studies of novel thrombus aspiration technologies are warranted to improve patient outcomes. Clinical Trial Registration: QUEST-STEMI trial ClinicalTrials.gov number: NCT03429608 Date of registration: February 12, 2018. The study was prospectively registered.

Platelets transfusion in Greece: Where, when, why? A national survey

BACKGROUND

Platelet transfusion is among the most useful therapeutic tools in modern clinical settings which mean that ensuring an adequate supply is of paramount importance.

AIM

The aim of our study was to record the use and wastage of platelet concentrates (PCs) in Greece, so as to come up with evidence-based interventions.

METHODS

The study was conducted during May and June 2015. We evaluated the use of random-donor platelets (RDPs) and single-donor apheresis platelets (SDPs). We analyzed such parameters as hospital department and diagnosis, indication for transfusion, PCs' age at the time of transfusion, and wastage rate.

RESULTS

We used data from 21 hospitals across the country. A total of 12,061 RDPs and 1189 SDPs were transfused, with an average of 4.84 (±2.72) and 1.12 (±2.73) units per episode, respectively. Most patients had been admitted to the internal medicine and hematology departments. The transfusions were mostly given prophylactically, usually in cases of acute leukemia, and mostly on the day before expiration. Wastage rate was 16.75% for RPDs and 2.70% for SDPs, primarily because of the expiration of the use-by date.

CONCLUSIONS

This is the first national survey regarding platelet transfusion in Greece. Since most patients were admitted in internal medicine and hematology departments, we recommend that the staff of the abovementioned departments should undergo training on contemporary transfusion guidelines. Platelet discard rate could further be lowered through the centralization of inventory management along with the extension of the lifetime of PCs by means of emerging technologies.

Elevated plasma levels of miR-29a are associated with hemolysis in patients with hypertrophic cardiomyopathy

BACKGROUND

miR-29a is a small non-coding RNA that is known to repress collagen synthesis. Interestingly, elevated plasma miR-29a was reported to correlate with pronounced myocardial fibrosis in patients with hypertrophic cardiomyopathy. The objective of this study was to elucidate the origin of plasma miR-29a, and evaluate its significance as a biomarker.

METHODS

miR-29a expression was evaluated in plasma (n=50) and myocardial samples (n=4) from patients with hypertrophic cardiomyopathy using RT-qPCR.

RESULTS

Although miR-29a was highly expressed in the myocardium, miR-29a plasma levels did not show any correlation with serum troponin I levels (r_s=-0.12, p=0.43), and the heart does not release significant amounts of miR-29a into the circulation via exosome secretion. Conversely, miR-29a was present in red blood cells, and plasma levels correlated significantly with markers of hemolysis: lactic dehydrogenase (r_s=0.36, p=0.01) and the absorbance of oxyhemoglobin at 414nm (r_s=0.39, p=0.006). Furthermore, the association between serum haptoglobin and the maximal blood flow velocity in the left ventricle outflow tract (r_s=-0.42, p=0.008) indicated that intravascular hemolysis is a manifestation of the disease.

CONCLUSIONS

miR-29a is highly expressed in myocardial tissue from patients with hypertrophic cardiomyopathy. In contrast, plasma miR-29a is primarily of nonmyocardial origin and is correlated significantly with the extent of hemolysis observed in these patients.

Increased values of mean platelet volume and platelet size deviation width may provide a safe positive diagnosis of idiopathic thrombocytopenic purpura

INTRODUCTION

It has been shown recently that platelet indices like mean platelet volume (MPV), platelet size deviation width (PDW) and platelet-to-large-cell ratio (P-LCR) are helpful in the discrimination between hyperdestructive thrombocytopenia like idiopathic thrombocytopenic purpura (ITP) and hypoproductive thrombocytopenia (HT). The aim of the study is to assess the reliability of these indices in the differentiation of ITP from other thrombocytopenias.

METHODS

We recruited 134 thrombocytopenic patients (69 men, 65 women) who were divided into two groups according to the underlying disease: group I (n = 63) included ITP patients, whereas group II (n = 71) included patients with HT due to myelosuppression secondary to chemotherapy for hematological malignancies. Platelet indices were derived from a Sysmex automated cell counter. Sensitivity, specificity, positive prognostic value, negative prognostic value, efficiency and Youden index were calculated.

RESULTS

Concerning MPV and PDW indices, sensitivity, specificity, positive prognostic value, negative prognostic value, efficiency and Youden index were 100% for the diagnosis of ITP. On the contrary, the values for P-LCR were significantly lower.

CONCLUSIONS

MPV and PDW can be safely relied on for a positive diagnosis of ITP. MPV and PDW were superior to P-LCR.

Haemarthrosis after superwarfarin poisoning

INTRODUCTION

Superwarfarins are widely used as rodenticides. They are similar to warfarin, but they are more potent and act longer. In case of poisoning, they cause severe bleeding, usually from multiple sites.

CASE REPORT

A 67-yr-old man was admitted with melaena, epistaxis and haemarthrosis in his left knee. PT, INR and aPTT were markedly increased. Initially, the patient was treated with blood and fresh frozen plasma (FFP) transfusions. However at the second day, PT, INR and aPTT were even worse. The combination of persistent coagulopathy, normal mixing studies, normal liver function tests and absence of hepatic failure or malabsorption syndromes lead to the suspicion of vitK dependent clotting factors deficiency due to superwarfarin poisoning. Indeed, the patient admitted a suicide attempt with rodenticide, although he had previously denied it. Psychiatric evaluation revealed a disturbed personality. Melaena stopped after 7 d. Then, the patient was administered 30 mg of vitK daily for a total period of 4 months.

CONCLUSIONS

Superwarfarin poisoning leads to severe bleeding, usually from multiple sites. Prolonged treatment with high doses of vitK is necessary. Haemarthrosis, as a complication of superwarfarin poisoning, is presented here for the first time in literature.

Discrimination indices as screening tests for β-thalassemic trait

The two most frequent microcytic anemias are beta-thalassemic trait (beta-TT) and iron deficiency anemia (IDA). Several discrimination indices have been proposed to distinguish between these two conditions. These indices are derived from several simple red blood cell indices, like red blood cell (RBC) count, mean cell volume, and RBC distribution width (RDW), as these are provided by electronic cell counters. The purpose of the study is to examine the diagnostic accuracy of six discrimination indices in the differentiation between IDA and beta-TT. The six discrimination indices that were examined were as follows: Mentzer Index (MI), Green & King Index (G&K), RDW Index (RDWI), England & Fraser Index (E&F), RDW, and RBC count. We calculated these indices on 373 patients (205 men, 168 women) with beta-TT and 120 patients (50 men, 70 women) with IDA, as well as their sensitivity, specificity, positive and negative prognostic value, efficiency, and Youden's index (YI). G&K shows the highest reliability, followed by E&F, RBC count, MI, and RDWI. On the contrary, RDW completely failed to differentiate between IDA and beta-TT. G&K proved to be the most reliable index as it had the highest sensitivity (75.06%), efficiency (80.12%), and YI (70.86%) for the detection of beta-TT. These six discrimination indices cannot be relied on for a safe differential diagnosis between beta-TT and IDA. They do have high specificity, but their sensitivity for the detection of beta-TT is not satisfactory. Consequently, they cannot be used neither as a screening tool for beta-TT because they could result in a significant number of false negative results.