Semi-supervised generative approach to chemical disorder: application to point-defect formation in uranium-plutonium mixed oxides.

Chemical disorder has a major impact on the characterization of the atomic-scale properties of highly complex chemical compounds, such as the properties of point defects. Due to the vast amount of possible atomic configurations, the study of such properties becomes intractable if treated with direct sampling. In this work, we propose an alternative approach, in which samples are selected based on the local atomic composition around the defect, and the defect formation energy is obtained as a function of this local composition with a reduced computational cost. We apply this approach to (U, Pu)O2 nuclear fuels. The formation-energy distribution is computed using machine-learning generative methods, and used to investigate the impact of chemical disorder and the range of influence of local composition on the defect properties. The predicted distributions are then used to calculate the concentration of thermal defects. This approach allows for the first time for the computation of the latter property with a physically meaningful exploration of the configuration space, and opens the way to a more efficient determination of physico-chemical properties in other chemically-disordered compounds such as high-entropy alloys.

Successful primary percutaneous coronary intervention determines the very long-term prognosis in ST-segment elevation myocardial infarction even in survivors of the acute phase. The ANIN Myocardial Infarction Registry.

INTRODUCTION: Successful primary percutaneous coronary intervention (pPCI) saves lives in the acute phase of ST-elevation myocardial infarction (STEMI) and improves the mid-term prognosis. Whether that benefit remains significant in very long-term follow-up and is associated with total ischaemic time (TIT), especially in survivors of the acute phase of STEMI, is unknown. AIM: We sought to investigate the impact of initial and final thrombolysis in myocardial infarction (TIMI) flow on long-term survival in a homogeneous, unselected group of patients with STEMI undergoing pPCI at a high-volume centre. MATERIAL AND METHODS: All consecutive STEMI patients treated with pPCI in our tertiary centre were enrolled in the ANIN Myocardial Infarction Registry. RESULTS: Among 1064 patients 871 (82%) had an occluded infarct artery (IRA) at baseline, while pPCI was successful in 885 (83%) patients. At 9 years all-cause and cardiovascular (CV) mortality were 28% (294 patients) and 19% (196 patients), respectively. Failure of pPCI was an independent predictor of long-term all-cause and CV mortality (OR = 1.5, 95% CI: 1.1-2.0, p = 0.03 and OR = 1.8, 95% CI: 1.3-2.7, p = 0.001, respectively). In survivors of the acute phase, occluded IRA at baseline was an independent predictor of all-cause mortality (OR = 1.5, 95% CI: 1.0-2.3, p = 0.04), while pPCI failure predicted CV mortality (OR = 1.8, 95% CI: 1.2-2.8, p = 0.005). Mortality rate increased with TIT even in patients with pPCI success. CONCLUSIONS: Angiographic results of pPCI determine the very long-term survival of STEMI patients, even in survivors of the acute phase of STEMI. Shortening of TIT is crucial.

Bedside prediction of 9-year mortality after ST­segment elevation myocardial infarction treated with primary percutaneous coronary intervention.

BACKGROUND: Despite similar underlying pathogenesis, clinical features, and management of ST­segment elevation myocardial infarction (STEMI), the long­term prognosis of patients is highly variable. The ability to stratify an individual's long­term mortality risk could facilitate development of focused interventions aimed at reducing poor long­term outcomes. AIMS: This study aimed to develop and validate a simple risk score based on routinely collected data for all­cause and cardiovascular 9-year mortality in a homogeneous group of patients with STEMI undergoing primary percutaneous coronary intervention (pPCI). METHODS: All consecutive patients with STEMI treated with pPCI were randomly divided into 2 groups. The first group was called the building group and was used to develop logistic regression models that were converted into a simple risk scores that estimated all­cause and cardiovascular long­term mortality risk (ANIN risk score I and II, respectively) and subsequently validated in the second group, called the validating group. RESULTS: The 9-year follow­up data were available in 1059 out of 1064 patients with STEMI. We developed 4 independent risk scores with the highest predictive accuracy of ANIN risk score I. Validation cohorts identified 4 most important risk factors: age, renal dysfunction, Killip class, and thrombolysis in myocardial infarction flow. Low, intermediate, and high­risk subgroups were identified based on those factors with different long­term mortalities: 10%, 37%, and 71%, respectively. CONCLUSIONS: Long­term mortality after STEMI treated with pPCI can be accurately predicted using 4-variable bedside risk score, which is ready to calculate right after pPCI. Patients in the low­risk group have an excellent prognosis despite having experienced potentially lethal disease.

Higher admission glycaemia independently of diagnosed or unrecognised diabetes mellitus is a risk factor for failed myocardial tissue reperfusion and higher mortality after primary angioplasty.

BACKGROUND AND AIM: Admission hyperglycaemia worsens reperfusion in ST-segment elevation myocardial infarction (STEMI). ST-segment elevation resolution parallels myocardial tissue reperfusion and predicts the outcome of primary percutaneous coronary intervention (pPCI). METHODS: We investigated whether higher glycaemia on admission impairs tissue-level reperfusion after pPCI for STEMI, as-sessed with the single-lead Schröder method of ST-segment resolution analysis (maxSTE). RESULTS: Among 323 patients (60.4 ± 11.5 years, 27.8% female), 13.4% of nondiabetic subjects and 58.2% of those with known diabetic history (17%) were admitted with glycaemia > 11.1 mmol/L. Failed tissue reperfusion, recognised if high-risk maxSTE criteria were fulfilled, was present among 25% of patients. The overall 180-day mortality rate was 6.8% (n = 22). Admission glycaemia ≥ 8.75 mmol/L appeared as the single risk factor for failed tissue reperfusion (ROC area = 0.638, standard error = 0.038, p < 0.001). Even after adjustment for diabetes history, patients with admission glycaemia ≥ 8.75 mmol/L (44.5%) had 2.36-fold higher risk (95% confidence interval [CI] 1.25-4.46, p = 0.008) of failed tissue reperfusion. After exclusion of patients with known diabetes and those with acute blood glucose level > 11.1 mmol/L (28%), admission glycaemia remained an independent predictor of failed tissue reperfusion (odds ratio [OR] 1.32, 95% CI 1.03-1.69, p = 0.028). Admission glycae-mia and failed tissue reperfusion (high- vs. low-risk maxSTE category) were the independent predictors of 180-day mortality (OR 1.18, 95% CI 1.05-1.32, p = 0.004 and OR 3.84, 95% CI 1.12-13.21, p = 0.033, respectively). CONCLUSIONS: Higher admission glycaemia in patients treated with pPCI for STEMI predicts failed myocardial tissue reperfusion and 180-day mortality, independently of prior or acute diabetic status.

Coronary computed tomography angiography for the assessment of SYNTAX score.

BACKGROUND: Coronary computed tomography angiography (CCTA) is applied in a growing number of clinical indications. This imaging modality is often regarded as a surrogate of invasive coronary angiography (ICA). In this paper we evaluate the applicability of CCTA alone in the assessment of the SYNTAX score. AIM: To evaluate the feasibility of calculating the SYNTAX score (SXScore) using CCTA alone instead of ICA. METHODS: Ninety consecutive patients with multivessel or left main (LM) coronary artery disease diagnosed with ICA, in whom prior CCTA scan was available, were included in a post-hoc analysis. First, the SXScore was calculated twice in ten-week intervals by two experienced observers using ICA for each patient. Then the SXScore was calculated twice using CCTA following the same regimen for each patient. Weighted kappa statistic was used to assess the intra-modality and inter-modality reproducibility of the SXScore. RESULTS: Ninety patients, aged 63.8 ± 8.9 years, 60% male, 64.4% with two-vessel disease, and 35.6% with three-vessel or LM disease met the inclusion criteria. 287 lesions were identified by ICA and 280 by CCTA (p = 0.56). Median total SXScore was 11.5 (10.2­14.0) as calculated by ICA and 16.0 (14.3­19.4) by CCTA (p < 0.001), and the results were moderately correlated (R = 0.38). Inter-modality agreement between ICA and CCTA for SXScore tertiles was moderate (kappa = 0.40). The intra-modality reproducibility of ICA and CCTA for SXScore tertiles was 0.47 and 0.51, respectively. CONCLUSIONS: Inter-modality agreement between CCTA and ICA for calculation of SXSscore is moderate but only slightly worse than intra-modality reproducibility for angiographic alone evaluation. Most of the observed variability can be assigned to the characteristic of the SXScore itself, not to the choice of imaging method. However, the application of CCTA for the assessment of SXScore should be used cautiously.

Comparison of Plaque Burden and Vessel Remodeling in Obstructive Saphenous Vein Graft Lesions as Assessed by Intravascular Ultrasound and Dual-source Computed Tomography.

PURPOSE: The aim of our study was to compare plaque burden and vessel remodeling of obstructive saphenous vein graft (SVG) lesions as assessed by dual-source computed tomography (DSCT) and intravascular ultrasound (IVUS). MATERIALS AND METHODS: Preintervention DSCT examination and IVUS were performed in consecutive patients before percutaneous treatment of the SVG lesion. SVG vessel and lumen areas were measured with use of DSCT and IVUS at the minimal lumen area (MLA) site and at proximal and distal reference sites. Plaque burden was defined as the ratio of plaque and vessel area. Remodeling index was defined as the ratio of the SVG area at the MLA site to the mean reference SVG area. RESULTS: Twenty-four obstructive SVG lesions were imaged with DSCT and IVUS before stent implantation in 24 patients. The SVG cross-sectional area at the MLA site measured by IVUS and DSCT was similar (17.0±4.5 vs. 17.3±5.3 mm, P=0.6) and well correlated (R=0.77, P<0.001). Similarly, plaque burden and remodeling index assessments did not differ significantly between the 2 imaging modalities (79.0%±4.0% vs. 81.0%±8.0%, P=0.18, and 1.09±0.22 vs. 1.07±0.32, P=0.7 for IVUS vs. DSCT for plaque burden and remodeling, respectively). The correlation between IVUS-assessed and DSCT-assessed plaque burden and remodeling index was moderate to good (R=0.55, P=0.01 and R=0.77, P<0.001, respectively, for plaque burden and remodeling index). CONCLUSIONS: There is moderate to good correlation between DSCT and IVUS in the assessment of vessel remodeling and plaque burden in obstructive SVG lesions. Noninvasive assessment and monitoring of SVG disease is feasible using DSCT.

Two-vessel chronic total occlusion. Complete percutaneous revascularisation.

Little is known about the success rate of second attempts to open chronic total occlusions. Two-vessel occlusion makes the procedure is even more challenging. Thus, embarking on complete percutaneous revascularization of such lesions requires adequate experience, especially after first unsuccessful attempt. We present a case of a 52-year-old male patient in whom successful percutaneous opening of two chronic coronary at staged procedure was performed.

Intervention on the left main coronary artery. Importance of periprocedural and follow-up intravascular ultrasonography guidance.

Periprocedural intravascular ultrasonography guidance for left main coronary artery stenting is well established. However, the role of this tool is also important at follow-up interventions. We present a case of a patient with previous history of left main coronary artery angioplasty. During a recent attempt to treat tight stenosis in the left anterior descending coronary artery, it was not possible to advance the stent into the left main coronary artery. Intravascular ultrasonography explained the difficulties encountered.

ST-elevation acute coronary syndrome in a patient after heart transplant.

The accelerated process of vasculopathy in heart transplant (HTx) recipients is a well-known factor of increased morbidity and mortality among this subset of patients. Heart transplant patients with acute coronary syndrome (ACS) usually do not present with typical symptoms. ST elevation (STE) is a very rare presentation of ACS in HTx recipients. We report a case of a female HTx patient, in whom STE-ACS was diagnosed and was subsequently treated with primary percutaneous coronary intervention.

The clinical significance and management of patients with incomplete coronary angiography and the value of additional computed tomography coronary angiography.

To assess the anatomical background and significance of incomplete invasive coronary angiography (ICA) and to evaluate the value of coronary computed tomography angiography (CTA) in this scenario. The current study is an analysis of high volume center experience with prospective registry of coronary CTA and ICA. The target population was identified through a review of the electronic database. We included consecutive patients referred for coronary CTA after ICA, which did not visualize at least one native coronary artery or by-pass graft. Between January 2009 and April 2013, 13,603 diagnostic ICA were performed. There were 45 (0.3 %) patients referred for coronary CTA after incomplete ICA. Patients were divided into 3 groups: angina symptoms without previous coronary artery by-pass grafting (CABG) (n = 11,212), angina symptoms with previous CABG (n = 986), and patients prior to valvular surgery (n = 925). ICA did not identify by-pass grafts in 21 (2.2 %) patients and in 24 (0.2 %) cases of native arteries. The explanations for an incomplete ICA included: 11 ostium anomalies, 2 left main spasms, 5 access site problems, 5 ascending aorta aneurysms, and 2 tortuous take-off of a subclavian artery. However, in 20 (44 %) patients no specific reason for the incomplete ICA was identified. After coronary CTA revascularization was performed in 11 (24 %) patients: 6 successful repeat ICA and percutaneous intervention and 5 CABG. Incomplete ICA constitutes rare, but a significant clinical problem. Coronary CTA provides adequate clinical information in these patients.

Relation between coronary plaque calcium deposits as described by computed tomography coronary angiography and acute results of stent deployment as assessed by intravascular ultrasound.

INTRODUCTION: The findings from intravascular ultrasound studies on the impact of calcium deposits on the results of stent implantation are conflicting. AIM: To evaluate whether calcium deposits as assessed by (CTCA) influence results of stent deployment. MATERIAL AND METHODS: The study population comprised 60 patients (43 male; age 64.2 ±8.6 years) who underwent CTCA before stent implantation. Lesion calcium score, total calcium length, and maximal area and maximal thickness of calcium deposits within the lesion segment were assessed. Plaques were divided into those with calcium score ≥ median (group 1), calcium score < median (group 2), and without calcium (group 3). Intravascular ultrasound (IVUS) was performed after attainment of optimal angiographic results of the stent procedure. Focal and diffuse stent expansion was defined as either minimum stent area (MSA) or mean stent area over the length of the stent divided by reference lumen area. RESULTS: The proximal reference segments of lesions with higher calcium score contained a larger plaque burden (47 ±12% vs. 41 ±9% vs. 34 ±18%, p = 0.02) - respectively for groups 1, 2, and 3. Positive correlation was observed between lesion calcium score and frequency of post-dilation (R = 0.28, p = 0.03). There was no difference in focal stent expansion (71 ±14% vs. 65 ±15% vs.71 ±15%, p = 0.3) or diffuse stent expansion (92 ±30% vs. 85 ±30% vs. 93 ±38%, p = 0.7) comparing groups 1, 2, and 3. Lesion calcium score, total length of calcium, and maximum area and thickness of calcium deposits did not correlate with focal or diffuse stent expansion. CONCLUSIONS: Lesions with a higher CTCA calcium score had larger reference plaque burden after stent implantation and more likely required post-dilation, but final stent expansion as assessed by IVUS was not affected by the amount of CTCA calcium provided an angiographically optimal result was achieved.

Risk is not flat. Comprehensive approach to multidimensional risk management in ST-elevation myocardial infarction treated with primary angioplasty (ANIN STEMI Registry).

INTRODUCTION: Current risk assessment concepts in ST-elevation myocardial infarction (STEMI) are suboptimal for guiding clinical management. AIM: To elaborate a composite risk management concept for STEMI, enhancing clinical decision making. MATERIAL AND METHODS: 1995 unselected, registry patients with STEMI treated with primary percutaneous coronary intervention (pPCI) (mean age 60.1 years, 72.1% men) were included in the study. The independent risk markers were grouped by means of factor analysis, and the appropriate hazards were identified. RESULTS: In-hospital death was the primary outcome, observed in 95 (4.7%) patients. Independent predictors of mortality included age, leukocytosis, hyperglycemia, tachycardia, low blood pressure, impaired renal function, Killip > 1, anemia, and history of coronary disease. The factor analysis identified two significant clusters of risk markers: 1. age-anemia- impaired renal function, interpreted as the patient-related hazard; and 2. tachycardia-Killip > 1-hyperglycemia-leukocytosis, interpreted as the event-related (hemodynamic) hazard. The hazard levels (from low to high) were defined based on the number of respective risk markers. Patient-related hazard determined outcomes most significantly within the low hemodynamic hazard group. CONCLUSIONS: The dissection of the global risk into the combination of patient- and event-related (hemodynamic) hazards allows comprehensive assessment and management of several, often contradictory sources of risk in STEMI. The cohort of high-risk STEMI patients despite hemodynamically trivial infarction face the most suboptimal outcomes under the current invasive management strategy.

Aspiration coronary thrombectomy for acute myocardial infarction increases myocardial salvage: single center randomized study.

OBJECTIVES: The aim of the study was to assess if aspiration thrombectomy in high risk patients with STEMI and angiographic evidence of thrombus may improve myocardial salvage. BACKGROUND: It is unclear if thrombus aspiration before percutaneous intervention (PCI) improves myocardial salvage. METHODS: The trial was a prospective randomized study. The inclusion criteria were: first STEMI within 12 hr from symptoms onset, culprit lesion in left anterior descending or right coronary artery, culprit artery TIMI flow ≤ 2 and angiographic evidence of thrombus. The primary endpoint was myocardial salvage index (MSI) as assessed by (99m) Tc-sestamibi SPECT imaging. RESULTS: We randomized 137 patients (98 male, mean age 64.1 ± 12.5 years) either to aspiration thrombectomy followed by standard PCI with stent implantation (n = 67) or to standard primary PCI (n = 70). Index perfusion defect was similar in both study groups: 34.2% ± 13.1% in thrombectomy group versus 37.1% ± 12.0% in primary PCI group (P = 0.2). MSI was larger in aspiration thrombectomy group than in control patients [25.4% (IQR 13.5-44) vs. 18.5% (IQR 7.7-30.3) respectively, P = 0.02]. The final infarct size was smaller in patients treated with aspiration thrombectomy (23.1% ± 13.3% vs. 28.9% ± 10.2% in the control group, P = 0.002). CONCLUSIONS: Aspiration thrombectomy improves myocardial salvage in high risk STEMI patients with angiographic evidence of thrombus.

The risk of non-sustained ventricular tachycardia after percutaneous alcohol septal ablation in patients with hypertrophic obstructive cardiomyopathy.

BACKGROUND: Percutaneous alcohol septal ablation (ASA) becomes an alternative option of treatment for symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). The procedure relieves left ventricular outflow tract obstruction, but produces a myocardial scar in patients who already have a substrate for life-threatening ventricular arrhythmia. OBJECTIVES: To examine the effect of ASA on the occurrence of non-sustained ventricular tachycardia (nsVT) on 24 h ambulatory Holter monitoring in HOCM patients. METHODS: Sixty-one consecutive patients (34 males, mean age 48 years), who underwent ASA between 1997 and 2003 were analyzed. Holter recordings were performed in each patient before and after ablation. RESULTS: Follow-up ranged from 60 to 125 months (median 116 months). The mean number of Holter recordings per patient was 2.7 (range 1-11) before and 8.3 (range 2-23) after ASA (p < 0.001). Non-sustained ventricular tachycardia occurred in 14 patients before and 27 patients after ASA (23 vs. 44%, p = 0.01). The percentage of Holter recordings with nsVT before and after ablation was similar (14.5 vs. 15.7%, p = 0.56, respectively). No difference was observed between the number of nsVT per Holter recording before and after ablation (0.21 vs. 0.24%, p = 0.65, respectively). The percentage of patients with nsVT after ASA was comparable to the proportion of patients with nsVT in a control group consisting of 705 patients with hypertrophic cardiomyopathy under follow-up at our institution (44.3 vs. 43.2%, p = 0.91). There was no significant difference in percentage of Holter recordings with nsVT with respect to sex, amount of alcohol used during ASA, peak creatine phosphokinase level, and gradient reduction at rest. CONCLUSION: Alcohol septal ablation affected neither the percentage of Holter recordings with nsVT nor the number of nsVT episodes per Holter recording among HOCM patients.

Clustering of admission hyperglycemia, impaired renal function and anemia and its impact on in-hospital outcomes in patients with ST-elevation myocardial infarction.

OBJECTIVE: To examine the incidence and inter-relationships between admission hyperglycemia, anemia and impaired renal function and its impact on clinical outcomes in patients with ST-elevation myocardial infarction (STEMI) treated with primary PCI. METHODS: The study group comprised 1880 patients with STEMI treated with primary PCI, enrolled in a prospective registry. RESULTS: The primary endpoint of in-hospital death occurred in 88 (4.7%) patients. Hyperglycemia (glucose >11.1mmol/L) was present in 352(18.7%), anemia (hematocrit <36% women, <39% men) in 396(21.1%), and increased serum creatinine (> or =1.2mg/dL women, > or =1.3mg/dL men) in 423(22.5%) patients. 1026(54.6%) subjects had none of the triad risk factors. Two overlapping conditions were observed in 207(11%) and 3 in 40(2.1%) patients. Compared to the expected distribution, an increased prevalence was observed in patients with zero, two or three risk factors, and decreased prevalence was present in patients with one risk factor (p<0.001). In multivariable model including important baseline risk factors and the whole triad risk factors, hyperglycemia, anemia, and increased serum creatinine were independently associated with the primary outcome (hazard ratio (HR); 95% confidence interval (CI): 2.67; 1.56-4.55, and 2.03; 1.19-3.46, and 1.72;1.01-2.93, respectively). Adjusted HR (95% CI) for the incidence of the primary outcome associated with 1, 2 and 3 examined risk factors as compared to 0 of the risk factors was 2.7(1.4-5.4), 5.4(2.6-8.3) and 8.3(3.0-23.2), respectively. CONCLUSIONS: Hyperglycemia, anemia, and impaired renal function are independently of each other related to in-hospital death in patients with STEMI treated with primary PCI. The triad risk factors cluster and accumulation of these risk factors is related to stepwise, additive increase of risk of in-hospital mortality.