Laser-driven low energy electron beams for single-shot ultra-fast probing of meso-scale materials and warm dense matter.

Laser wakefield acceleration has proven to be an excellent source of electrons and X-rays suitable for ultra-fast probing of matter. These novel beams have demonstrated unprecedented spatial and temporal resolution allowing for new discoveries in material science and plasma physics. In particular, the study of dynamic processes such as non-thermal melt and lattice changes on femtosecond time-scales have paved a way to completely new scientific horizons. Here, we demonstrate the first single-shot electron radiography measurement using an femtosecond electron source based on the downramp-density gradient laser-wakefield-acceleration with the use of a compact Ti:sapphire laser. A quasi-monoenergetic electron beam with mean energy of 1.9 ± 0.4 MeV and charge 77 ± 47 pC per shot was generated by the laser incident onto a gas target and collimated using a two ring-magnet beam path. High quality electron radiography of solid objects with spatial resolution better than 150 [Formula: see text]m was demonstrated. Further developments of this scheme have the potential to obtain single-shot ultrafast electron diffraction from dynamic lattices. This scheme poses a great promise for smaller scale university laboratories and facilities for efficient single-shot probing of warm dense matter, medical imaging and the study of dynamic processes in matter with broad application to inertial confinement fusion and meso-scale materials (mg g/cm[Formula: see text]).

ST-segment elevation myocardial infarction treated by radial or femoral approach in a multicenter randomized clinical trial: the STEMI-RADIAL trial.

OBJECTIVES: This study sought to compare radial and femoral approaches in patients presenting with ST-segment elevation myocardial infarction (STEMI) and undergoing primary percutaneous coronary intervention (PCI) by high-volume operators experienced in both access sites. BACKGROUND: The exact clinical benefit of the radial compared to the femoral approach remains controversial. METHODS: STEMI-RADIAL (ST Elevation Myocardial Infarction treated by RADIAL or femoral approach) was a randomized, multicenter trial. A total of 707 patients referred for STEMI <12 h of symptom onset were randomized in 4 high-volume radial centers. The primary endpoint was the cumulative incidence of major bleeding and vascular access site complications at 30 days. The rate of net adverse clinical events (NACE) was defined as a composite of death, myocardial infarction, stroke, and major bleeding/vascular complications. Access site crossover, contrast volume, duration of intensive care stay, and death at 6 months were secondary endpoints. RESULTS: The primary endpoint occurred in 1.4% of the radial group (n = 348) and 7.2% of the femoral group (n = 359; p = 0.0001). The NACE rate was 4.6% versus 11.0% (p = 0.0028), respectively. Crossover from radial to femoral approach was 3.7%. Intensive care stay (2.5 ± 1.7 days vs. 3.0 ± 2.9 days, p = 0.0038) as well as contrast utilization (170 ± 71 ml vs. 182 ± 60 ml, p = 0.01) were significantly reduced in the radial group. Mortality in the radial and femoral groups was 2.3% versus 3.1% (p = 0.64) at 30 days and 2.3% versus 3.6% (p = 0.31) at 6 months, respectively. CONCLUSIONS: In patients with STEMI undergoing primary PCI by operators experienced in both access sites, the radial approach was associated with significantly lower incidence of major bleeding and access site complications and superior net clinical benefit. These findings support the use of the radial approach in primary PCI as first choice after proper training. (Trial Comparing Radial and Femoral Approach in Primary Percutaneous Coronary Intervention [PCI] [STEMI-RADIAL]; NCT01136187).

Innovative technique for the direct determination of proteins in calcified aortic valves.

Aortal valve mineralization very frequently causes a genesis of aortic stenosis, which is the most often surgically treated heart disease. Hydroxyapatite deposits have been identified as one of the causes leading to the loss of elasticity of the aortic valves. It is known that phosphates/calcium is accumulated in valve tissues during mineralization, but the mechanism of this process remains unclear. The work is focused mainly on the study of protein composition of mineralized aortic valves by nano-liquid chromatography electrospray ionization in a quadrupole orthogonal acceleration time-of-flight mass spectrometry. New methodological approach based on direct enzymatic digestion of proteins contained in hydroxyapatite deposits was developed for the study of pathological processes connected with osteogenesis. Our objectives were to simplify the traditional analytical protocols of sample preparation and to analyze the organic components of the explanted aortic valves for significant degenerative aortic stenosis. The study of aortic valve mineralization on the molecular level should contribute to understanding this process, which should consequently lead to effective prevention as well as to new ways of treatment of this grave disease.

Design and rationale of the PRAGUE-12 trial: a large, prospective, randomized, multicenter trial that compares cardiac surgery with left atrial surgical ablation with cardiac surgery without ablation in patients with coronary and/or valvular heart disease plus atrial fibrillation.

Surgical ablation procedure can restore sinus rhythm (SR) in patients with atrial fibrillation (AF) undergoing cardiac surgery. However, it is not known whether it has any impact on clinical outcomes. There is a need for a randomized trial with long-term follow-up to study the outcome of surgical ablation in patients with coronary and/or valve disease and AF. Patients are prospectively enrolled and randomized either to group A (cardiac surgery with left atrial ablation) or group B (cardiac surgery alone). The primary efficacy outcome is the SR presence (without any AF episode) during a 24-hour electrocardiogram after 1 year. The primary safety outcome is the combined end point of death, myocardial infarction, stroke, and renal failure at 30 days. Long-term outcomes are a composite of total mortality, stroke, bleeding, and heart failure at 1 and 5 years. We finished the enrollment with a total of 224 patients from 3 centers in 2 countries in December 2011. Currently, the incomplete 1-year data are available, and the patients who enrolled first will have their 5-year visits shortly. PRAGUE-12 is the largest study to be conducted so far comparing cardiac surgery with surgical ablation of AF to cardiac surgery without ablation in an unselected population of patients who are operated on for coronary and/or valve disease. Its long-term results will lead to a better recognition of ablation's potential clinical benefits.

Comparison of cardiac surgery with left atrial surgical ablation vs. cardiac surgery without atrial ablation in patients with coronary and/or valvular heart disease plus atrial fibrillation: final results of the PRAGUE-12 randomized multicentre study.

AIMS: Surgical ablation procedure can restore sinus rhythm (SR) in patients with atrial fibrillation (AF) undergoing cardiac surgery. However, it is not known whether it has any impact on long-term clinical outcomes. METHODS AND RESULTS: This multicentre study randomized 224 patients with AF scheduled for valve and/or coronary surgery: group A (left atrial surgical ablation, n = 117) vs. group B (no ablation, n = 107). The primary efficacy outcome was the SR presence (without any AF episode) during a 24 h electrocardiogram (ECG) after 1 year. The primary safety outcome was the combined endpoint of death/myocardial infarction/stroke/renal failure at 30 days. A Holter-ECG after 1 year revealed SR in 60.2% of group A patients vs. 35.5% in group B (P = 0.002). The combined safety endpoint at 30 days occurred in 10.3% (group A) vs. 14.7% (group B, P = 0.411). All-cause 1-year mortality was 16.2% (A) vs. 17.4% (B, P = 0.800). Stroke occurred in 2.7% (A) vs. 4.3% (B) patients (P = 0.319). No difference (A vs. B) in SR was found among patients with paroxysmal (61.9 vs. 58.3%) or persistent (72 vs. 50%) AF, but ablation significantly increased SR prevalence in patients with longstanding persistent AF (53.2 vs. 13.9%, P < 0.001). CONCLUSION: Surgical ablation improves the likelihood of SR presence post-operatively without increasing peri-operative complications. However, the higher prevalence of SR did not translate to improved clinical outcomes at 1 year. Further follow-ups (e.g. 5-year) are warranted to show any potential clinical benefit which might occur later.

Age-related treatment strategy and long-term outcome in acute myocardial infarction patients in the PCI era.

BACKGROUND: Older age, as a factor we cannot affect, is consistently one of the main negative prognostic values in patients with acute myocardial infarction. One of the most powerful factors that improves outcomes in patients with acute coronary syndromes is the revascularization preferably performed by percutaneous coronary intervention. No data is currently available for the role of age in large groups of consecutive patients with PCI as the nearly sole method of revascularization in AMI patients. The aim of this study was to analyze age-related differences in treatment strategies, results of PCI procedures and both in-hospital and long-term outcomes of consecutive patients with acute myocardial infarction. METHODS: Retrospective multicenter analysis of 3814 consecutive acute myocardial infarction patients divided into two groups according to age (1800 patients ≤ 65 years and 2014 patients > 65 years). Significantly more older patients had a history of diabetes mellitus and previous myocardial infarctions. RESULTS: The older population had a significantly lower rate of coronary angiographies (1726; 95.9% vs. 1860; 92.4%, p < 0.0001), PCI (1541; 85.6% vs. 1505; 74.7%, p < 0.001), achievement of optimal final TIMI flow 3 (1434; 79.7% vs. 1343; 66.7%, p < 0.001) and higher rate of unsuccessful reperfusion with final TIMI flow 0-1 (46; 2.6% vs. 78; 3.9%, p = 0.022). A total of 217 patients (5.7%) died during hospitalization, significantly more often in the older population (46; 2.6% vs. 171; 8.5%, p < 0.001). The long-term mortality (data for 2847 patients from 2 centers) was higher in the older population as well (5 years survival: 86.1% vs. 59.8%). Though not significantly different and in contrast with PCI, the presence of diabetes mellitus, previous MI, final TIMI flow and LAD, as the infarct-related artery, had relatively lower impact on the older patients. Severe heart failure on admission (Killip III-IV) was associated with the worst prognosis in the whole group of patients, though its significance was higher in the youngers (HR 6.04 vs. 3.14, p = 0.051 for Killip III and 12.24 vs. 5.65, p = 0.030 for Killip IV). We clearly demonstrated age as a strong discriminator for the whole population of AMI patients. CONCLUSIONS: In a consecutive AMI population, the older group (>65 years) was associated with a less pronounced impact of risk factors on long-term outcome. To ascertain the coronary anatomy by coronary angiography and proceed to PCI if suitable regardless of age is crucial in all patients, though the primary success rate of PCI in the older age is lower. Age, when viewed as a risk factor, was a dominant discriminating factor in all patients.

Efficacy and safety of transient ulnar artery compression to recanalize acute radial artery occlusion after transradial catheterization.

Radial artery occlusion (RAO) can result from transradial catheterization. We compared the incidence of RAO with 2 heparin dosage regimens after transradial coronary angiography, and we evaluated the efficacy and safety of transient homolateral ulnar artery compression to achieve acute radial artery recanalization. Patients referred for coronary angiography were randomized to very-low-dose heparin (2,000 IU) or low-dose heparin (5,000 IU). On sheath removal, hemostasis was obtained using the TR band with a plethysmography-guided patent hemostasis technique. In the case of RAO as assessed by duplex ultrasonography 3 to 4 hours after hemostasis, immediate 1-hour ulnar artery compression was applied. Hematomas >15 cm(2) were also assessed. We randomized 465 patients, 222 in the 2,000-IU group and 243 in the 5,000-IU group. The baseline and procedural characteristics were comparable in both groups. The incidence of initial RAO was 5.9% in the 2,000-IU group and 2.9% in the 5,000-IU group (p = 0.17), with a compression time of 2.10 ± 0.78 hours and 2.25 ± 0.82 hours, respectively (p = 0.051). After ulnar artery compression, the final incidence of RAO was 4.1% in the 2,000-IU group and 0.8% in the 5,000-IU group (p = 0.03). The incidence of local hematoma was 2.3% and 3.7% in the 2,000- and 5,000-IU groups, respectively (p = 0.42). In conclusion, acute RAO after transradial catheterization can be recanalized by early 1-hour homolateral ulnar artery compression. This simple nonpharmacologic method was effective and safe in patients with very-low- and low-dose heparin. Nevertheless, the incidence of final RAO remained significantly lower after a higher anticoagulation level.

Mild to moderate functional tricuspid regurgitation: retrospective comparison of surgical and conservative treatment.

Background. Unoperated severe tricuspid regurgitation (TR) leads to the right ventricle (RV) failure. We wanted to determine if there was near-term postoperative progression of noncorrected mild to moderate functional TR in patients who underwent mitral valve surgery for chronic significant mitral regurgitation (MR) and if RV size and function were affected. Methods and Results. We compared two groups of patients retrospectively. In the first group (TVA+, n = 45), tricuspid valve annuloplasty (TVA) had been performed in conjunction with either mitral valve replacement (MVR) or mitral valve repair (MVP). The second group (TVA-, n = 22) underwent MVP or MVR without TVA. TVA+ group revealed a significant decrease in TR and right ventricle diameter. In the TVA- group, 7 patients (32%) showed a significant progression, by one or more grades, of noncorrected TR together with dilatation and decreased ejection fraction of the right ventricle. Conclusions. Tricuspid annuloplasty performed concurrently with MVP or MVR can prevent subsequent progression of tricuspid regurgitation along with right ventricular dilatation and systolic dysfunction in the near-term postoperative period.

Aortic annulus and ascending aorta: comparison of preoperative and periooperative measurement in patients with aortic stenosis.

BACKGROUND: Precise determination of the aortic annulus size constitutes an integral part of the preoperative evaluation prior to aortic valve replacement. It enables the estimation of the size of prosthesis to be implanted. Knowledge of the size of the ascending aorta is required in the preoperative analysis and monitoring of its dilation enables the precise timing of the operation. Our goal was to compare the precision of measurement of the aortic annulus and ascending aorta using magnetic resonance (MR), multidetector-row computed tomography (MDCT), transthoracic echocardiography (TTE), and transoesophageal echocardiography (TEE) in patients with degenerative aortic stenosis. METHODS AND RESULTS: A total of 15 patients scheduled to have aortic valve replacement were enrolled into this prospective study. TTE was performed in all patients and was supplemented with TEE, CT and MR in the majority of patients. The values obtained were compared with perioperative measurements. For the measurement of aortic annulus, MR was found to be the most precise technique, followed by MDCT, TTE, and TEE. For the measurement of ascending aorta, MR again was found to be the most precise technique, followed by MDCT, TEE, and TTE. CONCLUSION: In our study, magnetic resonance was found to be the most precise technique for the measurement of aortic annulus and ascending aorta in patients with severe degenerative aortic stenosis.