Comparative Analysis of Prothrombin Complex Concentrate and Fresh Frozen Plasma in the Management of Perioperative Bleeding after Coronary Artery Bypass Grafting

Background and Aim: Recent studies suggested that prothrombin complex concentrate (PCC) might be more effective than fresh frozen plasma (FFP) to reduce red blood cell (RBC) transfusion requirement after cardiac surgery. The benefits and risks associated with the use of PCC over FFP have been investigated in this study including patients undergoing isolated coronary artery bypass grafting(CABG) from a prospective, multicenter registry. Methods: This is a comparative analysis of 416 patients who received postoperatively FFP and 119 patients who received PCC with or without FFP after isolated CABG. Results: Mixed-effects regression analyses adjusted for multiple covariates and participating centers showed that PCC significantly decreased RBC transfusion (67.2% vs. 87.5%, adjusted OR 0.319, 95%CI 0.136-0.752) and platelet transfusion requirements (11.8% vs. 45.2%, adjusted OR 0.238, 95%CI 0.097-0.566) compared with FFP. The PCC cohort received a mean of 2.7\ub13.7 (median, 2.0, IQR 4) units of RBC and the FFP cohort received a mean of 4.9\ub16.3 (median, 3.0, IQR 4) units of RBC (adjusted coefficient, -1.926, 95%CI -3.357-0.494). The use of PCC increased the risk of KDIGO acute kidney injury (41.4% vs. 28.2%, adjusted OR 2.300, 1.203-4.400), but not of KDIGO acute kidney injury stage 3 (6.0% vs. 8.0%, OR 0.850, 95%CI 0.258-2.796) when compared with the FFP cohort. Conclusions: These results suggest that the use of PCC compared with FFP may reduce the need of blood transfusion after CABG. In view of the observational nature of this study, these results shoul

Value of Screening Asymptomatic Carotid Artery Stenosis Prior to Coronary Artery Bypass Grafting: Analysis of the E-CABG Registry

Background and aim: The aim of this study was to evaluate the prognostic impact of asymptomatic carotid artery stenosis(CAS) in patients undergoing isolated coronary artery bypass grafting(CABG). Methods:Patients from the multicenter, prospective E-CABG registry without history of stroke or transient ischemic attack and screened by duplex ultrasound for CAS before isolated CABG were included in this analysis. Results:Among 2813 patients screened by duplex ultrasound for asymptomatic CAS, 11.1% had a CAS of 50-59%, 6.0% of 60-69%, 3.1% of 70-79%, 1.4% of 80-89%, 0.5% of 90-99%, and 1.1% had carotid occlusion. Postoperative stroke occurred in 25 patients(0.9%). Lesions were bilateral in five patients(25%) and ipsilateral to a CAS 6550% in six patients(30%). In univariate analysis, the severity of CAS was associated with a significantly increased risk of stroke(p<0.0001). In multivariate analysis, a CAS of 90-99%(OR 12.03, 95%CI 1.34-108.23) and the presence of an occluded internal carotid artery(OR 8.783, 95%CI 1.820-42.40) were independent predictors of stroke along with urgency of the procedure, severe-massive bleeding according to the E-CABG classification and the presence of a porcelain ascending aorta. Conclusions: Among patients with asymptomatic CAS, the risk of stroke is significant only in patients with a stenosis 6590%. Since this condition has a low prevalence and when left untreated is associated with a relatively low rate of stroke, preoperative screening of asymptomatic CAS before CABG may not be justified. Instead, avoiding manipulation of diseased ascending aorta and prevention of excessive bleeding may be more effective measures to prevent stroke after CABG

Prognostic Impact of Prolonged Cross-Clamp Time in Coronary Artery Bypass Grafting

BACKGROUND:The prognostic impact of cross-clamp time (XCT) in patients undergoing isolated coronary artery bypass grafting (CABG) has not been thoroughly investigated.MATERIAL AND METHODS:2957 patients who underwent on-pump isolated CABG from the prospective multicentre E-CABG study were the subjects of this analysis.RESULTS:The mean XCT in this series was 58±25minutes Cross-clamp time was >60 minutes in 1134 patients (38.3%), >75minutes in 619 patients (20.9%) and >90minutes in 296 patients (10.0%). Multivariate analysis showed that XCT was an independent predictor of 30-day mortality (p75minutes (2.9% vs. 1.7%, p=0.002, OR 3.479, 95%CI 1.609-7.520). Analysis of 428 propensity score matched pairs showed that XCT >75minutes was associated with significantly increased risk of early mortality, prolonged use of inotropes, postoperative use of intra-aortic balloon pump, use of extracorporeal membrane oxygenation, atrial fibrillation, prolonged stay in the intensive care unit and of composite major adverse events.CONCLUSIONS:Isolated CABG is currently performed with prolonged XCT in a significant number of patients and this seems to be a determinant of poor early outcome.</p

Numerical simulation of the filling and curing stages in reaction injection moulding, using CFX

Mestrado em Engenharia MecânicaOs métodos habitualmente utilizados para a simulação de injecção em moldes envolvem um número considerável de simplificações, originando reduções significativas do esforço computacional mas, nalguns casos também limitações. Neste trabalho são efectuadas simulações de Reaction Injection Moulding (RIM) com o mínimo de simplificações, através da utilização do software de CFD multi-objectivos CFX, concebido para a simulação numérica de escoamentos e transferência de calor e massa. Verifica-se que o modelo homogéneo para escoamentos multifásicos do CFX, geralmente considerado o apropriado para a modelação de escoamentos de superfície livre em que as fases estão completamente estratificadas, é incapaz de modelar correctamente o processo de enchimento. Este problema é ultrapassado através da implementação do modelo não homogéneo juntamente com a condição de fronteira de escorregamento livre para o ar. A reacção de cura é implementada no código como uma equação de transporte para uma variável escalar adicional, com um termo fonte. São testados vários esquemas transitórios e advectivos, com vista ao reconhecimentos de quais os que produzem os resultados mais precisos. Finalmente, as equações de conservação de massa, quantidade de movimento, cura e energia são implementadas conjuntamente para simular os processos simultâneos de enchimento e cura presentes no processo RIM. Os resultados numéricos obtidos reproduzem com boa fidelidade outros resultados numéricos e experimentais disponíveis, sendo necessários no entanto tempos de computação consideravelmente longos para efectuar as simulações. ABSTRACT: Commonly used methods for injection moulding simulation involve considerable number of simplifications, leading to a significant reduction of the computational effort but, in some cases also to limitations. In this work, Reaction Injection Moulding (RIM) simulations are performed with minimum of simplifications, by using the general purpose CFD software package CFX, designed for numerical simulation of fluid flow and heat and mass transfer. The CFX’s homogeneous multiphase flow model, which is generally considered to be the appropriate choice for modelling free surface flows where the phases are completely stratified and the interface is well defined, is shown to be unable to model the filling process correctly. This problem is overcome through the implementation of the inhomogeneous model in combination with the free-slip boundary condition for the air phase. The cure reaction is implemented in the code as a transport equation for an additional scalar variable, with a source term. Various transient and advection schemes are tested to determine which ones produce the most accurate results. Finally, the mass conservation, momentum, cure and energy equations are implemented all together to simulate the simultaneous filling and curing processes present in the RIM process. The obtained numerical results show a good global accuracy when compared with other available numerical and experimental results, though considerably long computation times are required to perform the simulations

Impact of preoperative thrombocytopenia on the outcome after coronary artery bypass grafting

The impact of thrombocytopenia on postoperative bleeding and other major adverse events after cardiac surgery is unclear. This issue was investigated in a series of patients who underwent isolated coronary artery bypass grafting (CABG) from the prospective, multicenter E-CABG registry. Preoperative thrombocytopenia was defined as preoperative platelet count 9/L and it was considered moderate-severe when preoperative platelet count was 9/L. Multilevel mixed-effects regression analysis was performed to adjust the effect of thrombocytopenia on outcomes for baseline and operative covariates as well as for interinstitutional differences in patient-blood management. Among 7189 patients included in this analysis, 599 (8.3%) had preoperative thrombocytopenia. Patient with preoperative thrombocytopenia had an increased chest drainage output at 12 h (mean, 519 vs. 456 mL, adjusted coeff. 39, 95%CI 18–60) and rates of severe-massive bleeding (Universal Definition of Perioperative Bleeding (UDPB) severity grades 3–4: 12.7% vs. 8.1%, adjusted OR 1.47, 95%CI 1.11–1.93; E-CABG bleeding severity grades 2–3: 10.4% vs. 6.1%, adjusted OR 1.78, 95%CI 1.30–2.43). Thrombocytopenia was associated with an increased risk of hospital/30-day death (3.2% vs. 1.9%, adjusted OR 2.02, 95%CI 1.20–3.42), 1-year death (5.7% vs. 3.4%, adjusted HR 1.68, 95%CI 1.16–2.44), deep sternal wound infection (3.5% vs. 2.4%, adjusted OR 1.65, 95%CI 1.02–2.66), acute kidney injury (28.1% vs. 22.2%, OR 1.45, 1.18–1.78), and prolonged stay in the intensive care unit (mean, 3.6 vs 2.8 days, adjusted coeff. 0.74, 95%CI 0.40–1.09). Similar results were observed in a subset of patients with moderate-severe thrombocytopenia (51 patients, 0.7%). In particular, these patients had a markedly higher rate of acute kidney injury (40%, adjusted OR, 1.94, 95%CI 1.05–3.57), resternotomy for bleeding (7.8%, adjusted OR 3.49, 95%CI 1.20–10.21), and severe-massive bleeding (UDPB severity grades 3–4: 23.5%, adjusted OR 3.08, 95%CI 1.52–6.22; E-CABG bleeding severity grades 2–3: 23.5%, adjusted OR 4.43, 95%CI 2.15–9.15) compared to patients with normal preoperative platelet count. Mild preoperative thrombocytopenia is associated with increased risk of severe-massive bleeding, mortality, and other major adverse events after CABG. Such risks are markedly increased in patients with moderate-severe preoperative thrombocytopenia.</p

Prophylactic mechanical circulatory support for protected ventricular tachycardia ablation: A meta-analysis of the literature

Acute hemodynamic decompensation (AHD) during ventricular tachycardia (VT) ablation occurs in about 11% of cases. Prophylactic use of temporary mechanical circulatory support (pro-tMCS) has been applied to prevent AHD during VT ablation, but evidence supporting this practice is still lacking. This systematic review and meta-analysis assessed the procedural characteristics and outcomes of pro-tMCS for VT ablation. PubMed/Medline was screened until February 2020. Articles including adults receiving pro-tMCS for VT ablation were included, and a meta-analysis to compare proMCS and no-tMCS was performed. Primary outcome was in-hospital/30-day mortality. Five observational studies presenting 400 procedures (pro-tMCS: n = 187; no-tMCS: n = 213) were included. Baseline characteristics were comparable between groups. Impella and TandemHeart were used in 86.6% and 13.4% of cases, respectively. In the pro-tMCS group, more VTs were induced (mean difference: 0.52, confidence interval [CI]: 0.26-0.77, P < .0001), and patients remained in VT on average for 24.04 minutes longer (CI: 18.28-29.80, P < .00001). Procedural success was comparable between groups, as was VT recurrence. Pro-tMCS patients had an odds ratio of 0.55 (CI: 0.28-1.05, P = .07) for in-hospital/30-day mortality and 0.55 (CI: 0.32-0.94, P = .03) for mortality at follow-up. Sixty-four percent of no-tMCS patients received rescue tMCS. The most common tMCS-related complications were bleeding events. Pro-tMCS allowed for a prolonged time on VTs and the induction of more VTs. Although these advantages were not associated with differences in procedural success, VT recurrence, or in-hospital/30-day mortality in the overall population, pro-tMCS might improve long-term survival. Further prospective studies are urgently needed to confirm these results

Telemonitoring and Care Program for Left Ventricular Assist Device Patients during COVID-19 Outbreak:A European Experience

Coronavirus disease 2019 (COVID-19) radically modified the organization of healthcare systems with shutdown of routine activities and outpatient clinics. Herein, we report our institutional experience with a Telemonitoring and Care Program (TC-Program) to monitor and support left ventricular assist device (LVAD) patients during COVID-19 outbreak. This single-arm cohort study analyzed 156 patients who entered the TC-Program at our institution between April and August 2020. The TC-Program was based on routine phone calls to patients and a 24/7 emergency line. In November 2020, patients were asked for feedback on the TC-Program and checked for survival, transplant, or explant. The primary endpoint was the rate of TC-Program-driven interventions. Patients (males: 82.8%) were 61 years old (interquartile range [IQR]: 53.0-67.5) and on LVAD support for 1,266 days (IQR: 475-2,211). Patients were included in the TC-Program for a median time of 99 days (min:15, max:120) and received a median number of six phone calls (min:1, max:14). Twenty-three patients (14.7%) were referred for clinical evaluation after phone contact. Two patients (1.27%) were diagnosed with COVID-19: one of them died after intensive care, and one remained paucisymptomatic and recovered. Three patients asked to exit the program considering it not useful while the others gave high rates in terms of usefulness (median: 9, IQR: 8-10), information (median: 9, IQR: 8-10), good medical care (median: 9, IQR: 8-10), and psychologic support (median: 8, IQR: 7-10). A TC-Program based on the four ICSA principles (Inform, Care, Support, and Adapt) is feasible in LVAD patients and can be rapidly implemented during the COVID-19 pandemic

Biocompatibility of an apical ring plug for left ventricular assist device explantation: Results of a feasibility pre-clinical study

Background Patients receiving left ventricle assist devices (LVADs) as bridge to recovery remain a minority with 1%-5% of LVADs explanted after improvement of myocardial function. Nevertheless, considering the growing population of patients supported with LVADs, an increasing demand of new explantation strategies is expected in the near future. A novel plug for LVAD explantation has been developed and its biocompatibility profile needs to be proved. This study tested the biocompatibility of this novel plug in an in vivo ovine model. Methods Six adult Blackhead Persian female sheep received plug implantation on the cardiac apex via minimally invasive approach and were clinically observed up to 90 days. Echocardiography was performed to detect thrombus formation or further plug-related complications. After the observation period, euthanasia was performed and samples including the plug and the surrounding tissues were obtained to be analyzed with correlative light and electron microscopy. Organ necrosis, ischemia and peripheral embolism were investigated. Results Three animals survived surgery and completed the follow-up time without experiencing clinical complications. Echocardiographic controls excluded the presence of an intracavitary thrombus in the left ventricle (LV). Autopsy confirmed no signs of local infection, LV thrombus or peripheral embolism. Light and electron microscopy revealed an intact epithelium covering a layer of connective tissue on the plug surface facing the heart lumen. Conclusions This novel apical plug for LVAD explantation allows for endothelial and connective tissue growth on its ventricular side within 90 days from surgery. Further studies are required to fully demonstrate the biocompatibility of this apical plug and investigate the optimal anticoagulation regimen to be applied after implantation