Insights into the Complexation Mechanism of a Promising Lipophilic PyTri Ligand for Actinide Partitioning from Spent Nuclear Fuel.

The challenging issue of spent nuclear fuel (SNF) management is being tackled by developing advanced technologies that point to reduce environmental footprint, long-term radiotoxicity, volumes and residual heat of the final waste, and to increase the proliferation resistance. The advanced recycling strategy provides several promising processes for a safer reprocessing of SNF. Advanced hydrometallurgical processes can extract minor actinides directly from Plutonium and Uranium Reduction Extraction raffinate by using selective hydrophilic and lipophilic ligands. This research is focused on a recently developed N-heterocyclic selective lipophilic ligand for actinides separation to be exploited in advanced Selective ActiNide EXtraction (SANEX)-like processes: 2,6-bis(1-(2-ethylhexyl)-1H-1,2,3-triazol-4-yl)pyridine (PyTri-Ethyl-Hexyl-PTEH). The formation and stability of metal-ligand complexes have been investigated by different techniques. Preliminary studies carried out by electrospray ionization mass spectrometry (ESI-MS) analysis enabled to qualitatively explore the PTEH complexes with La(III) and Eu(III) ions as representatives of lanthanides. Time-resolved laser fluorescence spectroscopy (TRLFS) experiments have been carried out to determine the ligand stability constants with Cm(III) and Eu(III) and to better investigate the ligand complexes involved in the extraction process. The contribution of a 1:3 M/L complex, barely identified by ESI-MS analyses, was confirmed as the dominant species by TRLFS experiments. To shed light on ligand selectivity toward actinides over lanthanides, NMR investigations have been performed on PTEH complexes with Lu(III) and Am(III) ions, thereby showing significant differences in chemical shifts of the coordinating nitrogen atoms providing proof of a different bond nature between actinides and lanthanides. These scientific achievements encourage consideration of this PyTri ligand for a potential large-scale implementation.

Activation of the Aromatic Core of 3,3'-(Pyridine-2,6-diylbis(1H-1,2,3-triazole-4,1-diyl))bis(propan-1-ol)-Effects on Extraction Performance, Stability Constants, and Basicity.

The "CHON" compatible water-soluble ligand 3,3'-(pyridine-2,6-diylbis(1H-1,2,3-triazole-4,1-diyl))bis(propan-1-ol) (PTD) has shown promise for selectively stripping actinide ions from an organic phase containing both actinide and lanthanide ions, by preferential complexation of the former. Aiming at improving its complexation properties, PTD-OMe was synthesized, bearing a methoxy group on the central pyridine ring, thus increasing its basicity and hence complexation strength. Unfortunately, solvent extraction experiments in the range of 0.1-1 mol/L nitric acid proved PTD-OMe to be less efficient than PTD. This behavior is explained by its greater pKa value (pKa = 2.54) compared to PTD (pKa = 2.1). This counteracts its improved complexation properties for Cm(III) (log ß3(PTD-OMe) = 10.8 ± 0.4 versus log ß3(PTD) = 9.9 ± 0.5).

Time-Resolved Laser Fluorescence Spectroscopy Study of the Coordination Chemistry of a Hydrophilic CHON [1,2,3-Triazol-4-yl]pyridine Ligand with Cm(III) and Eu(III).

The complexation of Cm(III) and Eu(III) with the novel i-SANEX complexing agent 2,6-bis[1-(propan-1-ol)-1,2,3-triazol-4-yl]pyridine (PTD) was studied by time-resolved laser fluorescence spectroscopy (TRLFS). The formation of 1:3, 1:2, and 1:1 metal/ligand complexes was identified upon increasing PTD concentration in 10-3 mol/L HClO4 and in 0.44 mol/L HNO3 solutions. For all these complexes, stability constants were determined at different acid concentrations. Though under the extraction conditions proposed for an An/Ln separation process, that is, for 0.08 mol/L PTD in 0.44 mol/L HNO3, 1:3 complexes represent the major species, a significant fraction of 1:2 complexes was found. This is caused by ligand protonation, and results in lower Eu(III)/Am(III) separation factors compared to SO3-Ph-BTP, until now considered the i-SANEX reference ligand. Focused extraction studies performed at lower proton concentration, where the 1:3 complex is formed exclusively, confirm this assumption.

Hydrophilic Clicked 2,6-Bis-triazolyl-pyridines Endowed with High Actinide Selectivity and Radiochemical Stability: Toward a Closed Nuclear Fuel Cycle.

There is still an evident need for selective and stable ligands able to separate actinide(III) from lanthanide(III) metal ions in view of the treatment of the accumulated radioactive waste and of the recycling of minor actinides. We have herein demonstrated that hydrophilic 2,6-bis-triazolyl-pyridines are able to strip all actinides in all the different oxidation states from a diglycolamide-containing kerosene solution into an acidic aqueous phase. The ascertained high actinide selectivity, efficiency, extraction kinetics, and chemical/radiolytic stability spotlight this hydrophilic class of ligands as exceptional candidates for advanced separation processes fundamental for closing the nuclear fuel cycle and solving the environmental issues related to the management of existing nuclear waste.

A case of multiple sclerosis improvement following removal of heavy metal intoxication: lessons learnt from Matteo's case.

Multiple sclerosis (MS) is a chronic progressive disease of the central nervous system (CNS) provoking disability and neurological symptoms. The exact causes of SM are unknown, even if it is characterized by focal inflammatory lesions in CNS accompanied by autoimmune reaction against myelin. Indeed, many drugs able to modulate the immune response of patients have been used to treat MS. More recently, toxic metals have been proposed as possible causes of neurodegenerative diseases. The objective of this study is to investigate in vivo the impact of heavy metal intoxication in MS progression. We studied the case of a patient affected by MS, who has been unsuccessfully treated for some years with current therapies. We examined his levels of toxic heavy metals in the urine, following intravenous "challenge" with the chelating agent calcium disodium ethylene diamine tetraacetic acid (EDTA).The patient displayed elevated levels of aluminium, lead and mercury in the urine. Indeed, he was subjected to treatment with EDTA twice a month. Under treatment, the patient revealed in time improved symptoms suggestive of MS remission. The clinical data correlated with the reduction of heavy metal levels in the urine to normal range values. Our case report suggests that levels of toxic metals can be tested in patients affected by neurodegenerative diseases as MS.

Promising Lipophilic PyTri Extractant for Selective Trivalent Actinide Separation from High Active Raffinate.

Within a spent nuclear fuel recycling strategy, in the past few years, the pyridine-bis-triazole unit was found to be rather effective and selective in minor actinide (MA) separation from synthetic high active raffinate (HAR). In this research work, the main features of the recently studied PTEH ligand were investigated in order to evaluate its potentialities in SANEX-like processes. Its applicability in advanced separation processes was demonstrated, even at process temperatures. It manifested satisfactory extraction properties for a successful selective An separation from Ln, easy cation release, and adequate extraction kinetics as well as outstanding hydrolytical and radiolytical stability. All the results collected in this work allowed the scientists on the committee of the H2020 GENIORS project to promote PTEH as a concrete alternative to the reference CyMe4-BTBP ligand.

Deep Eutectic Solvents: Promising Co-solvents to Improve the Extraction Kinetics of CyMe4-BTBP.

In this communication, we report on the use of deep eutectic solvents (DESs) for processing nuclear waste, with a view to selectively recovering minor actinides (MA) from highly active raffinate solutions. DESs are an interesting new class of green and eco-sustainable solvents. Herein, a representative family of DES was tested as a co-solvent for MA/lanthanides partitioning based on Selective ActiNide EXtraction (SANEX)-like hydrometallurgical processes. The reference system exploits the CyMe4-BTBP lipophilic extractant for selective MA recovery, but the slow kinetics is the main limitation toward the industrial implementation. A selection of hydrophilic DESs has been proposed as a phase transfer catalyst and tested to improve the process performances. In this work, the radiochemical stability and the extraction behavior of these DESs have been ascertained. Moreover, a preliminary optimization of system composition has been achieved. This study underlines a catalytic effect of DES that can be proficiently exploited to enhance CyMe4-BTBP extraction and selectivity.

Structural properties of the chelating agent 2,6-bis(1-(3-hydroxypropyl)-1,2,3-triazol-4-yl)pyridine: a combined XRD and DFT structural study.

The conformational isomerism of the chelating agent 2,6-bis(1-(3-hydroxypropyl)-1,2,3-triazol-4-yl)pyridine (PTD), exploited in fuel reprocessing in spent nuclear waste, has been studied by single crystal X-ray diffraction analysis in combination with an extensive DFT conformational investigation. In the solid-state, the elucidated crystal structure (i.e., not yet published) shows that by thermal treatment (DSC) no other phases are observed upon crystallization from the melt, indicating that the conformation observed by X-ray data is rather stable. Mapping of intermolecular and intramolecular noncovalent interactions has been used to elucidate the unusual arrangement of the asymmetric unit. Considerations relating to the stability of different conformational isomers in aqueous and non-aqueous solutions are also presented. The accurate structural description reported here might open various research topics such as the potential of PTD to act as an outer sphere ligand in the formation of second sphere coordination complexes and their interconversion by mechanochemical means.

Transvenous removal of pacing and implantable cardiac defibrillating leads using single sheath mechanical dilatation and multiple venous approaches: high success rate and safety in more than 2000 leads.

AIMS: The aim of the present study was to describe a 10 years single-centre experience in pacing and defibrillating leads removal using an effective and safe modified mechanical dilatation technique. METHODS AND RESULTS: We developed a single mechanical dilating sheath extraction technique with multiple venous entry site approaches. We performed a venous entry site approach (VEA) in cases of exposed leads and an alternative transvenous femoral approach (TFA) combined with an internal transjugular approach (ITA) in the presence of very tight binding sites causing failure of VEA extraction or in cases of free-floating leads. We attempted to remove 2062 leads [1825 pacing and 237 implantable cardiac defibrillating (ICD) leads; 1989 exposed at the venous entry site and 73 free-floating] in 1193 consecutive patients. The VEA was effective in 1799 leads, the TFA in 28, and the ITA in 205; in the overall population, we completely removed 2032 leads (98.4%), partially removed 18 (0.9%), and failed to remove 12 leads (0.6%). Major complications were observed in eight patients (0.7%), causing three deaths (0.3%). CONCLUSION: Mechanical single sheath extraction technique with multiple venous entry site approaches is effective, safe, and with a good cost effective profile for pacing and ICD leads removal.

Effects of bariatric surgery on early myocardial alterations in adult severely obese subjects.

OBJECTIVE: Aim of this study was to investigate the effect of weight loss on structural and functional myocardial alterations in severely obese subjects treated with bariatric surgery. PATIENTS AND METHODS: Thirteen severely obese patients (2 males and 11 females) were enrolled in the study. All subjects underwent conventional 2D color Doppler echocardiography. The new ultrasonic techniques used were: (a) integrated backscatter for the analysis of myocardial reflectivity, referred to pericardial interface as expression of myocardial structure (increase in collagen content) and of cyclic variation index as expression of intrinsic myocardial contractility and (b) color Doppler myocardial imaging (CDMI) for the analysis of strain and strain rate (myocardial deformability). All subjects underwent bariatric surgery and were resubmitted to echocardiographic and biochemical examination 6-24 months after surgery. RESULTS: The main finding of the present study was a quite complete normalization of myocardial functional and structural alterations after weight loss. In particular, the cyclic variation index at septum level improved from 14.6 +/- 7.0 before to 25.7 +/- 11.2 (means +/- SD) after surgery (controls: 36.2 +/- 9.1). Mean reflectivity at septum level significantly decreased from 55.8 +/- 9.5 to 46.5 +/- 8.8 (controls: 43.0 +/- 8.0). Also, the strain at septum level significantly improved after surgery (from -11.9 +/- 3.2 to -20.4 +/- 5.3; controls: -23.4 +/- 9). CONCLUSION: This study establishes: (a) the utility of new ultrasonic techniques to detect very early structural and functional myocardial alterations in severely obese patients, and (b) the regression of these subclinical abnormalities after weight loss achieved by bariatric surgery.

Left ventricular function in normotensive young adults with well-controlled type 1 diabetes mellitus.

The aim of this study was to determine whether early myocardial structural and functional systolic and diastolic alterations in asymptomatic and uncomplicated patients with type 1 diabetes mellitus (DM) could be detected using the new highly sensitive echocardiographic techniques of integrated backscatter and color Doppler myocardial imaging. Forty asymptomatic and uncomplicated patients with type 1 DM and 40 gender- and age-matched normal controls were studied. All patients were analyzed by conventional and new echocardiographic techniques (integrated backscatter and color Doppler myocardial imaging). Patients with DM showed reduced systolic function compared with controls, evidenced by significantly lower peak strain, strain rates, and cyclic variation indexes at the septum (p <0.0001, <0.01, and <0.001, respectively) and at the posterior wall level (p <0.0001, <0.0001, and <0.001, respectively). On receiver-operating characteristic curve analysis, systolic strain and the cyclic variation index showed the highest discriminating power for separating patients with DM and control subjects. Neither structural or ultrastructural nor diastolic functional abnormalities were detected. On univariate regression analysis, a significant inverse correlation was found for DM duration with conventional (E/A ratio) and unconventional (tissue Doppler imaging E/A ratio) indexes of diastolic function, in the absence of any correlation for systolic function. In conclusion, highly sensitive ultrasonic techniques demonstrate evidence of left ventricular systolic dysfunction in the early stage of type 1 DM, in the absence of ultrastructural and left ventricular diastolic functional abnormalities.

Early textural and functional alterations of left ventricular myocardium in mild hypothyroidism.

The aim of the present study was to evaluate cardiac function and texture in patients with subclinical hypothyroidism (sHT) both by conventional and new ultrasonic intramyocardial tissue techniques. sHT was characterized by normal serum free tetraiodotironine and free triiodotironine levels and slightly increased serum TSH level. Twenty-four patients affected by sHT and 24 sex- and age-matched healthy volunteers were studied. All subjects were submitted to conventional two-dimensional (2D)-color Doppler echocardiography, pulsed wave tissue Doppler imaging (PWTDI) for the analysis of the diastolic function, color Doppler myocardial imaging (CDMI) for the analysis of regional strain and strain-rate and integrated backscatter (IBS) for the evaluation of intrinsic contractility and tissue characterization. The results of the present study were: (a) the detection in sHT subjects of a lower cyclic variation index (CVI) indicating an altered myocardial intrinsic contractility; (b) a higher ultrasonic myocardial reflectivity indicating an altered myocardial texture; (c) the detection of lower systolic strain and strain-rate indicating an alteration of myocardial regional deformability; (d) an initial impairment of left ventricular diastolic function indicated by a decrease of peak E mitral flow velocity and an increase of peak A mitral flow velocity. All parameters studied with conventional 2D-echo in sHT patients were comparable with controls, except for a mild alteration in diastolic function. A significant correlation among systo-diastolic modifications detected by CDMI and IBS and serum TSH levels were found. The CVI at septum, the PWDTI S-peak wave and the systolic strain at septum were inversely related to the serum TSH levels. In conclusion, the new intramyocardial ultrasonic techniques confirm and extend the previous knowledge on the effect of the sHT on the heart, allowing the detection of early ultrastructural and regional functional systolic and diastolic abnormalities.

Admission C-reactive protein serum levels and survival in patients with acute myocardial infarction with persistent ST elevation.

OBJECTIVE: To evaluate the prognostic value of a single and early determination of high sensitivity C-reactive protein levels at admittance in patients with acute myocardial infarction with persistent ST elevation. PATIENTS AND METHODS: We evaluated high-sensitivity C-reactive protein levels in 247 consecutive acute myocardial infarction with persistent ST elevation patients at admittance. Patients were monitored for the occurrence of major adverse cardiovascular events. RESULTS: Mean follow-up was 26 months. High C-reactive protein levels were principally associated with age > or = 65 years (P=0.01), diabetes (P=0.03) and reduced left ventricle ejection fraction (P=0.048). We observed a significant C-reactive protein level difference between the major adverse cardiovascular event-free group and the major adverse cardiovascular event group (28.2+/-21.9 vs. 47.7+/-31.9 mg/l, P=0.03), between deceased patients group (vs. 81.5+/-51.8 mg/l, P<0.001) and early deaths (vs. 129.5+/-71.9 mg/l, P<0.001). Kaplan-Meier plots for survival and major adverse cardiovascular event occurrence showed a significant separation (P=0.01 and 0.002 by log-rank test, respectively) between high and low C-reactive protein level groups. C-reactive protein levels were independent risk predictors of major adverse cardiovascular events (odds ratio 2.931, 95% confidence interval 1.512-5.893; P=0.046) and death (odds ratio 5.068, 95% confidence interval 2.056-20.195; P=0.04). Patients with high C-reactive protein levels and age > or = 65 years were at highest risk for major adverse cardiovascular event occurrence (odds ratio 5.658, 95% confidence interval 2.898-6.249; P=0.022) and death (odds ratio 8.120, 95% confidence interval 5.656-22.729; P=0.03). CONCLUSIONS: High C-reactive protein levels identify patients with a worse prognosis after acute myocardial infarction with persistent ST elevation. The evaluation of C-reactive protein and age may provide a tool to select high-risk patients.

Mechanical prevention of distal embolization during primary angioplasty: safety, feasibility, and impact on myocardial reperfusion.

BACKGROUND: Effective myocardial reperfusion after primary percutaneous coronary intervention (PCI) may be limited by distal embolization. We tested the safety, feasibility, and efficacy of the FilterWire-Ex (FW), a distal embolic protection device, as an adjunct to primary PCI. METHODS AND RESULTS: Fifty-three consecutive patients undergoing primary PCI with FW protection were compared with a matched control group treated by primary PCI alone. Successful FW positioning was obtained in 47 patients (89%) without complications. Histological analysis of the content of the last 13 filters showed multiple embolic debris in all cases. FW use was associated with lower postinterventional corrected TIMI frame count (22+/-14 versus 31+/-19; P=0.005) and higher occurrence of grade 3 myocardial blush (66% versus 36%; P=0.006) and early ST-segment elevation resolution (80% versus 54%; P=0.006). At multivariate analysis, FW use was the only independent predictor of early ST-segment elevation resolution and of grade 3 myocardial blush. FW patients showed lower peak creatine kinase-MB release (236+/-172 versus 333+/-219 ng/mL; P=0.013) and greater improvement at 30 days in left ventricular wall motion score index (-0.30+/-0.19 versus -0.18+/-0.26; P=0.008) and ejection fraction (+7+/-4% versus +4+/-7%; P=0.012). CONCLUSIONS: FW use during primary PCI is feasible and safe. Distal embolization prevention appears to exert a beneficial effect on markers of myocardial reperfusion and on left ventricular function improvement at 30 days.

Incremental value of ultrasonic tissue characterization (backscatter) in the evaluation of left ventricular myocardial structure and mechanics in essential arterial hypertension.

BACKGROUND: Ultrasonic backscatter parameters were analyzed in hypertensive patients and divided into groups according to both severity of left ventricular hypertrophy (LVH) (group A: no LVH [n=52]; B: mild to moderate LVH [n=55]; and C: severe LVH [n=10]) and left ventricular geometry (normal geometry [n=44]; concentric remodeling [n=8]; concentric hypertrophy [n=25]; and eccentric hypertrophy [n=40]). METHODS AND RESULTS: We studied 117 male, essential hypertensive patients and 19 normotensive, age-matched (40+/-5 years), healthy subjects who served as controls. Ambulatory and office blood pressure measurements were taken and 2-dimensional Doppler echocardiography and ultrasonic myocardial integrated backscatter (IBS) were performed. A group from the hypertensive study population (n=16) was observed after a period of pharmacological antihypertensive treatment to determine the behavior of backscatter parameters in relation to eventual regression of left ventricular mass (LVM). The cyclic variation index (CVIs) of the backscatter signal at the septum level was grouped according to each LVM level and was 29.4+/-9.3 (controls), 15+/-11 (group A), 9.5+/-10 (group B), and -1.5+/-8.6 (group C) (P<0.001). CVI septum values grouped according to left ventricular geometry were 15+/-11 (normal geometry), 12+/-7 (concentric remodeling), 7+/-11 (concentric hypertrophy), and 7.8+/-11 (eccentric hypertrophy) (P<0.01). Follow-up data demonstrate a significant reduction of LVM after therapy, as well as a significant increase in CVIs toward normal values. CONCLUSIONS: Hypertensive patients with higher LVM had the worst prognosis; in fact, those patients had the most significant CVI alterations. Regression of LVM subsequent to chronic pharmacological therapy induces a normalization of ultrasonic backscatter parameters. Ultrasonic tissue characterization (backscatter) analysis could allow early identification of patients at risk of developing complications of hypertensive cardiopathy.

Severe aortic stenosis and myocardial function: diagnostic and prognostic usefulness of ultrasonic integrated backscatter analysis.

BACKGROUND: The aim of this study was to assess the myocardial reflectivity pattern in severe aortic valve stenosis through the use of integrated backscatter (IBS) analysis. Patients with aortic stenosis (AS) were carefully selected in the Department of Cardiology. METHODS AND RESULTS: Thirty-five subjects (AS: valve orifice < or =1 cm2; 12 female; mean age, 71.8+/-6.2 years) and 25 healthy subjects were studied. All subjects of the study had conventional 2D-Doppler echocardiography and IBS. Backscatter signal was sampled at the septum and posterior wall levels. Patients with AS were divided into 2 groups: 16 patients with initial signs of congestive heart failure and a depressed left ventricular systolic function (DSF) (ejection fraction [EF] range, 35% to 50%) and 19 asymptomatic patients with normal left ventricular systolic function (NSF) (EF >50%). Myocardial echo intensity (pericardium related) was significantly higher at the septum and posterior wall levels in DSF than in NSF and in control subjects. IBS variation, as an expression of variation of the signal, appeared to be significantly lower in AS with DSF than in NSF and in control subjects, at both the septum and posterior wall levels. Patients with DSF underwent aortic valve replacement, and, during surgical intervention, a septal myocardial biopsy was made for evaluation of myocardium/fibrosis ratio. Abnormally increased echo intensity was detected in left ventricular pressure overload by severe aortic stenosis and correlated with increase of myocardial collagen content (operating biopsy). CONCLUSIONS: One year after aortic valve replacement, we observed a significant reduction of left ventricular mass, and, only if pericardial indexed IBS value (reduction of interstitial fibrosis) decreased, it was possible to observe an improvement of EF and of IBS variation.

Left ventricular remodeling after primary coronary angioplasty in patients treated with abciximab or intracoronary adenosine.

BACKGROUND: Primary angioplasty is the best treatment of acute myocardial infarction but fails to achieve adequate myocardial reperfusion in 25% to 30% of patients, despite TIMI grade 3 flow. Drug treatment aimed at reducing the no-reflow phenomenon may improve myocardial salvage, thus preventing left ventricular remodeling. Our aim was to evaluate the impact of abciximab and adenosine on immediate angiographic results and on 6-month left ventricular remodeling. METHODS: Ninety consecutive patients undergoing primary angioplasty with coronary stenting were randomized in a sequential alternating fashion to standard abciximab treatment (ABCX) group, intracoronary adenosine distal to the occlusion (ADO) group, or neither (CTRL) group. All patients underwent a clinical and echocardiographic follow-up at 1 and 6 months. The primary end point was the prevalence of 6-month left ventricular remodeling. RESULTS: Baseline clinical, echocardiographic, and angiographic characteristics were similar. Mean final corrected TIMI frame count was 17 +/- 9, 16 +/- 12, and 23 +/- 11 frames in ABCX, ADO, and CTRL patients, respectively (P = .002). Angiographic no-reflow was observed in 7%, 13%, and 17% of ABCX, ADO, and CTRL patients, respectively (P > .20). At 6 months, left ventricular remodeling occurred in 7%, 30%, and 30% of ABCX, ADO, and CTRL patients, respectively (P = .045), with a percent increase in end-diastolic volume of 5% +/- 13%, 15% +/- 15%, and 12% +/- 18% (P = .04). CONCLUSIONS: During primary angioplasty, abciximab enhances myocardial reperfusion, translating into a reduced incidence of 6-month left ventricular remodeling. In contrast, adenosine administration improves angiographic results but does not prevent left ventricular remodeling.

Distal embolization during primary angioplasty: histopathologic features and predictability.

BACKGROUND: Distal embolization during primary percutaneous coronary interventions (PCIs) may affect myocardial reperfusion. We evaluated the prevalence and features of embolization during primary PCI and its relationship with clinical and angiographic variables. METHODS: Forty-six consecutive patients with acute myocardial infarction underwent primary PCI with a filter-based distal protection device. Histopathologic analysis was performed on retrieved embolic fragments, assessing the presence and relative amount of fibrin, necrosis, lipid droplets, collagen, mucopolysaccharides, and leukocytes, as well as the total debris volume. Such variables were related to baseline clinical and angiographic variables. RESULTS: Embolic material was recovered in 41 (89%) of 46 cases, with a mean total debris volume of 1.2 +/- 2.2 mm3. Prevalent histopathologic patterns were organized thrombus (47%), fresh thrombus (29%), and plaque fragments (24%). At multivariate analysis, none of the baseline clinical variables considered significantly predicted the total debris volume. Among angiographic variables, angiographic signs of high thrombus burden (cut-off coronary occlusion pattern or large intracoronary minus image) independently predicted the total debris volume at multivariate analysis (odds ratio 15.8, P < .005). Compared with its nonuse, abciximab did not affect the total number and the mean total volume of embolized material (15 +/- 16 vs 10 +/- 8 fragments, 1.5 +/- 2.5 vs 1.0 +/- 1.9 mm3, respectively, for both P > .20), or its qualitative composition. CONCLUSIONS: Distal embolization occurs in most patients during primary PCI and mainly consists of plaque fragments and partially organized thrombi, which are likely to be scarcely responsive to antiplatelet drugs. Baseline angiographic signs of a high thrombus burden are the only significant predictors of the extent of distal embolization.

Simvastatin does not inhibit intimal hyperplasia and restenosis but promotes plaque regression in normocholesterolemic patients undergoing coronary stenting: a randomized study with intravascular ultrasound.

BACKGROUND: Restenosis after coronary stenting is mainly caused by intimal hyperplasia. Both experimental and clinical studies suggest that statins may be able to inhibit intimal hyperplasia and, therefore, in-stent restenosis (ISR), by mechanisms beyond lipid lowering. METHODS: In a 12-month study, we randomized 71 normocholesterolemic patients to 20 mg simvastatin or no treatment, 2 weeks before elective coronary stenting. Patients were evaluated by quantitative coronary angiography and intravascular ultrasound, immediately after the index procedure and at the 12-month catheterization. RESULTS: Binary ISR was present in 15% and in 18% of simvastatin-treated patients and controls, respectively (P = NS). Intimal hyperplasia did not differ significantly between the 2 groups (3.6 +/- 1.8 vs 3.8 +/- 2.3 mm3/mm, 34% +/- 15% vs 35% +/- 23% for simvastatin vs controls, P = NS). However, persistent plaque decreased with simvastatin but increased in controls (-4.0 +/- 4.0 vs +1.6 +/- 3.8 mm3/mm, -14% +/- 10% vs +6% +/- 12%, P < .05). The same behavior was shown by intermediate plaques at nonstented sites (-2.5 +/- 3.0 vs +1.0 +/- 3.0 mm3/mm, -10% +/- 8% vs +9% +/- 9%, P < .05). Major adverse events at 12 months were present in 11% and 24% of simvastatin-treated patients and controls, respectively (P = .20). CONCLUSIONS: In normocholesterolemic patients undergoing coronary stenting, simvastatin does not prevent intimal hyperplasia or ISR, but it promotes atherosclerotic regression both at stented and at nonstented sites.

Symptomatic acute myocardial infarction in a cardiac transplant recipient successfully treated with primary coronary angioplasty: evidence of prognostic importance of chest pain after cardiac transplantation.

Accelerated coronary artery disease remains the limiting factor in the long-term survival of heart transplant (HT) recipients and occurs in approximately 50% of patients by 5 years after transplantation. Sequelae of graft arteriosclerosis include congestive heart failure (due to acute or chronic ischemia), graft loss, and death. Unfortunately, as a consequence of cardiac denervation, symptoms are often atypical or completely absent, and thus presentation with an acute coronary syndrome is extremely uncommon. We describe the case of an HT recipient with a typical clinical picture of an acute myocardial infarction (MI), who presented to our hospital 2 hours after the onset of symptoms and was successfully treated with primary percutaneous transluminal coronary angioplasty (PTCA).