Enhancing predictive accuracy of the cardiac risk score in open abdominal aortic surgery: the role of left ventricular wall motion abnormalities

BackgroundOpen abdominal aortic surgery carries many potential complications, with cardiac adverse events being the most significant concern. The Vascular Study Group Cardiac Risk Index (VSG-CRI) is a commonly used tool for predicting severe cardiac complications and guiding clinical decision-making. However, despite the potential prognostic significance of left ventricular wall motion abnormalities (LVWMAs) and reduced LV ejection fraction (LVEF) for adverse outcomes, the VSG-CRI model has not accounted for them. Hence, the main objective of this study was to analyze the added value of LV wall motion on the discriminatory power of the modified VSG-CRI in predicting major postoperative cardiac complications.MethodsA prospective study was conducted involving 271 patients who underwent elective abdominal aortic surgery between 2019 and 2021. VSG-CRI scores were calculated, and preoperative transthoracic echocardiography was conducted for all patients. Subsequently, a modified version of the VSG-CRI, accounting for reduced LVEF and LVWMAs, was developed and incorporated into the dataset. The postoperative incidence of the composite endpoint of major adverse cardiac events (MACEs), including myocardial infarction, clinically relevant arrhythmias treated with medicaments or by cardioversion, or congestive heart failure, was assessed at discharge from the index hospitalization, with adjudicators blinded to events. The predictive accuracy of both the original and modified VSG-CRI was assessed using C-Statistics.ResultsIn total, 61 patients (22.5%) experienced MACEs. Among these patients, a significantly higher proportion had preoperative LVWMAs compared to those without (62.3% vs. 32.9%, p < 0.001). Multivariable regression analysis revealed the VSG-CRI [odds ratio (OR) 1.46, 95% confidence interval (CI) 1.21–1.77; p < 0.001] and LVWMA (OR 2.76; 95% CI 1.46–5.23; p = 0.002) as independent predictors of MACEs. Additionally, the modified VSG-CRI model demonstrated superior predictability compared to the baseline VSG-CRI model, suggesting an improved predictive performance for anticipating MACEs following abdominal aortic surgery [area under the curve (AUC) 0.74; 95% CI 0.68–0.81 vs. AUC 0.70; 95% CI 0.63–0.77; respectively].ConclusionThe findings of this study suggest that incorporating preoperative echocardiography can enhance the predictive accuracy of the VSG-CRI for predicting MACEs after open abdominal aortic surgery. Before its implementation in clinical settings, external validation is necessary to confirm the generalizability of this newly developed predictive model across different populations

Morphology and composition of Ni-Co alloy powders electrodeposited from ammoniacal electrolyte

In this paper, the morphology and phase structure of Ni-Co powders electrodeposited from ammoniacal electrolyte are investigated as a function of alloy powder composition. Composition of the electrolyte, i.e. the ratio of Ni(2+)/Co(2+) concentration is found to influence both, the phase structure and the morphology of Ni-Co alloy powders. It is shown that the current density practically does not influence the morphology of Ni-Co alloy powders as well as alloy powder composition. At the highest ratio of the Ni(2+)/Co(2+) ions typical spongy particles were obtained. With the decrease of the Ni(2+)/Co(2+) ions ratio agglomerates of the size of about 100 mu m, composed of a large number of fern-like dendrites on their surface were obtained. At the lowest Ni(2+)/Co(2+) concentration ratio, among more dendritic particles, agglomerates typical for pure Co powder deposition were detected. It is also shown that depending on the Ni(2+)/Co(2+) ratio different types of Ni and Co codeposition could be detected: anomalous and irregular. At the Ni(2+)/Co(2+) ions ratio higher than 1 only beta-Ni phase was detected, while at concentration ratios Ni(2+)/Co(2+) LT 1 h.c.p. alpha-Co phase together with beta-Ni phase was detected in the alloy powder deposit

Characterization of electrodeposited powders of the system Ni-Mo-O

The electrodeposition of the Ni-Mo-O alloy powders from ammonium chloride containing electrolytes for different Ni/Mo ions concentration ratios was investigated by the polarization measurements. The morphology, chemical composition and phase composition of the electrodeposited Ni-Mo-O alloy powders were investigated using DSC, TGA, SEM, EDS and XRD analysis. According to the EDS results, the powder composition depends on the Ni/Mo ions concentration ratio. However, some deviations in the composition of the as-deposited powders, as the result of the position of the EDS analysis, revealed that the composition of such powders is not homogeneous. The as-deposited alloy powders were nanocrystalline showing only one broad XRD peak around 44 degrees. Their morphology was found to depend on the Ni/Mo ions concentration ratio. After annealing of the Ni-Mo-O powders for 2 h in N-2 atmosphere at 600 degrees C, well-defined crystals for all powders were detected by SEM. The presence of the NiMoO4 phase only or NiMoO4 and MoO3 phases in these powders (XRD), depending on the Ni/Mo ions concentration ratio, was identified. The additional EDS analysis on different recrystallized grains revealed the influence of the annealing on a composition of the alloy powders. (c) 2008 Elsevier Ltd. All rights reserved

Electrodeposition and morphology of Ni, Co and Ni-Co alloy powders - Part II. Ammonium chloride supporting electrolyte

Polarization characteristics of the processes of Ni and Co powders and Ni-Co alloy powders electrodeposition from ammonium chloride containing supporting electrolyte and their morphologies are investigated as a function of Ni2+ and Co2+ ions concentrations. It is found that the shape of the polarization curves in all cases is practically defined by the shape of the polarization curve for hydrogen evolution. It is shown that correct polarization curves, as well as the morphology of electrodeposited powders are sensitive to the ratio of Ni2+/CO2+ ions concentration. Characteristic feature of powder particles obtained from chloride containing electrolytes is the presence of cone-shaped cavities. In the case of Ni powder cauliflower and spongy type particles are detected, while Co powder contains only spongy type particles. In all cases of alloy powder formation anomalous type of co-deposition is detected. (c) 2006 Elsevier Ltd. All rights reserved

Electrodeposition of Fe powder from acid electrolytes

Polarization characteristics of the electrodeposition processes of Fe powders from sulfate and chloride electrolytes and the morphology of the obtained powders were investigated. The morphology depended on the anion pre sence in the electrolyte but not on the current density in the investigated range. A characteristic feature of the dendritic powder with cauliflower endings obtained from sulfate electrolyte is the presence of cone-like cavities and the crystallite morphology of the powders surface. On the other hand, Fe powders electrodeposited from chloride electrolyte appear in the form of agglomerates. A soap solution treatment applied as a method of washing and drying provides good protection from oxidation of the powders.U ovom radu prikazani su rezultati ispitivanja polarizacionih karakteristika procesa taloženja Fe prahova iz sulfatnih i hloridnih elektrolita, kao i morfologija dobijenog praha. Utvrđeno je da morfologija čestica zavisi od vrste anjona prisutnih u elektrolitu, ali ne i od primenjene gustine struje u ispitivanom opsegu. Karakteristično za čestice koje su istaložene iz sulfatnih elektrolita je da su one dendritične sa karfiolastim, kristaliničnim završecima i da poseduju kupaste šupljine. Kod Fe prahova istaloženih iz hloridnih elektrolita uočeni su aglomerati. Korišćenje rastvora sapuna u procesu pranja i sušenja prahova pokazao se kao dobar metod zaštite praha od oksidacije

Morphology, internal structure and growth mechanism of electrodeposited Ni and Co powders

In this paper the morphology (SEM analysis), the internal structure (cross-section analysis) and the growth mechanism of Ni and Co powders electrodeposited from ammoniacal electrolyte are investigated. It is shown that morphology and the internal structure of those powders are quite different. For Ni powder, all particles are of the same morphology, cauliflower-like type. In the case of Co powder, generally two types of particles are detected: (1) dendrite particles and (2) different types of agglomerates, compact, spongy-like and ball-like ones. The growth mechanism for all agglomerates is based on the fact that with the time of growth the disperse (dendrite) agglomerate is branching in different directions and at the tip of each branch spherical diffusion takes over the planar one, providing conditions for the growth of compact deposit. After some time, these branches form compact deposit all over the agglomerate surface and the same agglomerate further grows as a compact one, until it falls off from the electrode surface. Characteristic of all agglomerates is the presence of deep cavities on their surface and the fern-like dendrites on the bottom for most of these cavities

Characterization of electrodeposited powders of the system Ni-Mo-O

The electrodeposition of the Ni-Mo-O alloy powders from ammonium chloride containing electrolytes for different Ni/Mo ions concentration ratios was investigated by the polarization measurements. The morphology, chemical composition and phase composition of the electrodeposited Ni-Mo-O alloy powders were investigated using DSC, TGA, SEM, EDS and XRD analysis. According to the EDS results, the powder composition depends on the Ni/Mo ions concentration ratio. However, some deviations in the composition of the as-deposited powders, as the result of the position of the EDS analysis, revealed that the composition of such powders is not homogeneous. The as-deposited alloy powders were nanocrystalline showing only one broad XRD peak around 44 degrees. Their morphology was found to depend on the Ni/Mo ions concentration ratio. After annealing of the Ni-Mo-O powders for 2 h in N-2 atmosphere at 600 degrees C, well-defined crystals for all powders were detected by SEM. The presence of the NiMoO4 phase only or NiMoO4 and MoO3 phases in these powders (XRD), depending on the Ni/Mo ions concentration ratio, was identified. The additional EDS analysis on different recrystallized grains revealed the influence of the annealing on a composition of the alloy powders