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Constrictive pericarditis (CP) is an infrequent complication following heart transplantation (HTx) and arises from diverse postoperative occurrences, including mediastinitis, pericardial effusion, or allograft rejection. Indeed, this rare clinical entity can be misdiagnosed as a rejection episode or restrictive cardiomyopathy. In this report, we present the case of a 43-year-old male who underwent HTx 1.5 years prior and was subsequently admitted to our center due to the gradual onset of symptoms indicative of right congestive heart failure, with an initial diagnosis of constrictive pericarditis., Competing Interests: Conflicts of interest: The authors declare no conflict of interest

Introduction: The use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) as a direct bridge to heart transplantation (BTT) is not common in adults worldwide. BTT with ECMO is associated with increased early/mid-term mortality compared with other interventions. In low- and middle-income countries (LMIC), where no other type of short-term mechanical circulatory support is available, its use is widespread and increasingly used as rescue therapy in patients with cardiogenic shock (CS) as a direct bridge to heart transplantation (HT)., Objective: To assess the outcomes of adult patients using VA-ECMO as a direct BTT in an LMIC and compare them with international registries., Methods: We conducted a single-center study analyzing consecutive adult patients requiring VA-ECMO as BTT due to refractory CS or cardiac arrest (CA) in a cardiovascular center in Argentina between January 2014 and December 2022. Survival and adverse clinical events after VA-ECMO implantation were evaluated., Results: Of 86 VA-ECMO, 22 (25.5%) were implanted as initial BTT strategy, and 52.1% of them underwent HT. Mean age was 46 years (SD 12); 59% were male. ECMO was indicated in 81% for CS, and the most common underlying condition was coronary artery disease (31.8%). Overall, in-hospital mortality for VA-ECMO as BTT was 50%. Survival to discharge was 83% in those who underwent HT and 10% in those who did not, p < .001. In those who did not undergo HT, the main cause of death was hemorrhagic complications (44%), followed by thrombotic complications (33%). The median duration of VA-ECMO was 6 days (IQR 3-16). There were no differences in the number of days on ECMO between those who received a transplant and those who did not. In the Spanish registry, in-hospital survival after HT was 66.7%; the United Network of Organ Sharing registry estimated post-transplant survival at 73.1% ± 4.4%, and in the French national registry 1-year posttransplant survival was 70% in the VA-ECMO group., Conclusions: In adult patients with cardiogenic shock, VA-ECMO as a direct BTT allowed successful HT in half of the patients. HT provided a survival benefit in listed patients on VA-ECMO. We present a single center experience with results comparable to those of international registries., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Hypertrophic cardiomyopathy is a condition associated with an increased risk of sudden death compared to the general population. Extended septal myectomy surgery has been suggested to impact the reduction of sudden death events according to various publications. The aim of this study was to assess changes in the prevalence of sudden death predictors in a population of patients undergoing extended septal myectomy surgery., Methods: Ninety-four consecutive patients underwent extended septal myectomy surgery due to symptomatic hypertrophic cardiomyopathy. Risk factors for sudden death, as defined by the American Heart Association and the European Society of Cardiology, were evaluated before and three months after surgery., Results: The mean age of the population was 57 ± 13 years. A significant reduction was observed in the maximum septal thickness from 21.3 to 14 mm (p<0.001), along with a decrease in the anteroposterior diameter of the left atrium from 51 to 47 mm (p=0.021). Resting intraventricular gradients decreased from 49.2 to 6.4 mmHg (p<0.001), and Valsalva-induced gradients decreased from 93.9 to 8.7 mmHg (p<0.001). Non-sustained ventricular tachycardia decreased from 6% to 2% (p<0.001), and atrial fibrillation decreased from 30% to 15% (p<0.001). Ischemic behavior during exercise stress echo decreased from 6% to 0%, and the European Society of Cardiology sudden death risk score reduced from 3.32 to 1.44 (p<0.001)., Conclusions: In this cohort of hypertrophic cardiomyopathy patients, extended septal myectomy surgery was associated with a reduction in the number and magnitude of sudden death predictors, potentially explaining the reduced mortality reported in the literature., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objectives: Veno-arterial Extracorporeal membrane oxygenation (VA ECMO) is a salvage intervention in patients with cardiogenic shock (CS), and cardiac arrest (CA) refractory to standard therapies. The design of ECMO Teams has achieved the standardization of processes, although its impact on survival and prognosis is unknown., Objective: We aimed to analyze whether the creation of an ECMO Team has modified the prognosis of patients undergoing VA ECMO for refractory CS or CA., Materials and Methods: . We conducted a single-center retrospective cohort study. Patients with refractory CS or CA who underwent VA ECMO were divided in two consecutive periods: from 2014 to April 2019 (pre-ECMO T) and from May 2019 to December 2022 (Post ECMO T). The main outcomes were survival on ECMO, in-hospital survival, complications, and annual ECMO volume., Results: Eighty-three patients were included (36 pre-ECMO T and 47 post-ECMO T). The mean age was 53 +/-13 years. The most common reason for device indication was different: postcardiotomy shock (47.2%) pre-ECMO T and refractory cardiogenic shock (29.7%) post-ECMO T. The rate of extracorporeal cardiopulmonary resuscitation was 14.5%. The median duration of VA ECMO was longer after ECMO team implementation: 8 days (IQR 5-12.5) vs. five days (IQR 2-9, p=0.04). Global in-hospital survival was 45.8% (38.9% pre-ECMO T vs. 51.1% post-ECMO T; p=0.37), and the survival rate from VA ECMO was 60.2% (55.6% pre-ECMO T vs 63.8% post-ECMO T; p= 0.50). The volume of VA ECMO implantation was significantly higher in the post-ECMO team period (13.2 +/3.5 per year vs. 6.5 +/-3.5 per year, p: 0.02). The rate of complications was similar in both groups., Conclusions: After the implementation of an ECMO team, there was no statistical difference in the survival rate of patients treated with VA ECMO. However, a significant increase in the number of patients supported per year was observed after the implementation of this multidisciplinary team. Post-ECMO T, the most common reason for device indication was cardiogenic shock, with longer run times and a higher rate of extracorporeal cardiopulmonary resuscitation., Competing Interests: Conflictos de interés Ninguno

Venoarterial extracorporeal membrane oxygenation (VA ECMO) is a form of temporary mechanical circulatory support and simultaneous extracorporeal gas exchange for acute cardiorespiratory failure, including refractory cardiogenic shock (CS) and cardiac arrest (CA). Few studies have assessed predictors of successful weaning (SW) from VA ECMO. This systematic review and meta-analysis aimed to identify a multiparameter strategy associated with SW from VA ECMO. PubMed and the Cochrane Library and the International Clinical Trials Registry Platform were searched. Studies reporting adult patients with CS or CA treated with VA ECMO published from the year 2000 onwards were included. Primary outcomes were hemodynamic, laboratory, and echocardiography parameters associated with a VA ECMO SW. A total of 11 studies (n=653) were included in this review. Pooled VA ECMO SW was 45% (95%CI: 39-50%, I2 7%) and in-hospital mortality rate was 46.6% (95%CI: 33-60%; I2 36%). In the SW group, pulse pressure [MD 12.7 (95%CI: 7.3-18) I2 = 0%] and mean blood pressure [MD 20.15 (95%CI: 13.8-26.4 I2 = 0) were higher. They also had lower values of creatinine [MD -0.59 (95%CI: -0.9 to -0.2) I2 = 7%], lactate [MD -3.1 (95%CI: -5.4 to -0.7) I2 = 89%], and creatine kinase [-2779.5 (95%CI: -5387 to -171) I2 = 38%]. And higher left and right ventricular ejection fraction, MD 17.9% (95%CI: -0.2-36.2) I2 = 91%, and MD 15.9% (95%CI 11.9-20) I2 = 0%, respectively. Different hemodynamic, laboratory, and echocardiographic parameters were associated with successful device removal. This systematic review demonstrated the relationship of multiparametric assessment on VA ECMO SW.

Objective: The purpose of the present study was to compare survival outcomes in propensity score-matched patients aged 70 years or greater receiving a bilateral internal thoracic artery graft with patients receiving a single internal thoracic artery graft., Methods: Among 4083 consecutive patients with isolated coronary artery bypass grafting who underwent operation between January 2001 and December 2018, we identified 1300 patients aged 70 years or greater; of these, 968 received a bilateral internal thoracic artery (bilateral internal thoracic artery group) and 332 received a single internal thoracic artery (single internal thoracic artery group). Propensity score matching was used to reduce the preoperative patient differences. The 10-year survival and postoperative complications were compared between the 2 groups., Results: A Kaplan-Meier curve at 10 years of follow-up showed that crude survival was significantly superior in patients with bilateral internal thoracic artery grafts than in patients with single internal thoracic artery grafts (67.0% ± 2.5% vs 56.0% ± 3.4%, respectively; P < .016). In the actuarial survival, estimates for propensity score-matched patients with a bilateral internal thoracic artery showed a significantly higher rates of survival than patients with a single internal thoracic artery by the end of follow-up (66.0% ± 5.3% vs 53.0% ± 3.9%, respectively; hazard ratio, 0.64; 95% confidence interval, 0.44-0.94; P = .022, univariable Cox Model and multivariable analysis hazard ratio, 0.66; 95% confidence interval, 0.45-0.97; P = .036 Cox model). Postoperative complications were all similar between the single internal thoracic artery and bilateral internal thoracic artery groups., Conclusions: The use of bilateral internal thoracic artery grafting in older patients improves 10-year survival, with similar postoperative morbidity. This surgical technique might have beneficial effects in survival in patients aged more than 70 years. Its use could be considered more frequently., (Copyright © 2020 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Introduction: Veno-arterial extracorporeal membrane oxygenation may be used to support patients with refractory cardiogenic shock. Many patients can be successfully weaned, the ability of some medications to facilitate weaning from veno-arterial extracorporeal membrane oxygenation were reported. To date, there are limited studies investigating the impact of levosimendan on veno-arterial extracorporeal membrane oxygenation weaning. The objective of this systematic review and meta-analysis was to assess the effects of levosimendan on successful weaning from veno-arterial extracorporeal membrane oxygenation and survival in adult patients with cardiogenic shock., Methods: We performed a systematic review and meta-analysis (PubMed, the Cochrane Library, and the International Clinical Trials Registry Platform published from the year 2000 onwards) investigating whether levosimendan offers advantages compared to standard therapy or placebo, in cardiogenic shock adult patients treated with veno-arterial extracorporeal membrane oxygenation. The primary outcome was veno-arterial extracorporeal membrane oxygenation successful weaning, whereas secondary outcome was all-cause mortality at the longest follow-up available. We pooled risk ratio and 95% confidence interval using fixed and random effects models according to the heterogeneity., Results: A total of five non-randomized clinical trials comprising 557 patients were included, 299 patients for levosimendan and 258 patients for control groups. The pooled prevalence of veno-arterial extracorporeal membrane oxygenation successful weaning was 61.4% (95% confidence interval 39.8-82.9%), and all-cause mortality was 36% (95% confidence interval 29.6-48.8%). There was a significant increase in veno-arterial extracorporeal membrane oxygenation successful weaning with levosimendan compared to the controls (risk ratio = 1.42 (95% confidence interval 1.12-1.8), p for effect = 0.004, I 2  = 71%). A decrease risk of all-cause mortality in the levosimendan group was also observed, risk ratio = 0.62 (95% confidence interval 0.44-0.88), p for effect = 0.007, I 2  = 36%., Conclusion: The use of levosimendan on adult patients with cardiogenic shock may facilitate the veno-arterial extracorporeal membrane oxygenation weaning and reduce all-cause mortality. Few articles of this topic are available, and prospective, randomized multi-center trials are warranted to conclude decisively on the benefits of levosimendan in this setting.

Antecedentes Y Objetivos: El sistema de calificación APACHE II permite predecir la mortalidad intrahospitalaria en terapia intensiva. Sin embargo, no está validado para cirugía cardíaca, ya que no posee buena capacidad diferenciadora. El objetivo es determinar el valor pronóstico de APACHE II en el postoperatorio de procedimientos cardíacos., Materiales Y Métodos: Se analizó en forma retrospectiva la base de cirugía cardíaca. Se incluyó a pacientes intervenidos entre 2017 y 2018, de los cuales se calculó la puntuación APACHE II. Se utilizó curva ROC para determinar el mejor valor de corte. El punto final primario fue mortalidad intrahospitalaria. Como puntos finales secundarios se evaluó la incidencia de bajo gasto cardíaco (BGC), accidente cerebrovascular (ACV), sangrado quirúrgico y necesidad de diálisis. Se realizó un modelo de regresión logístico multivariado para ajustar a las variables de interés., Resultados: Se analizó a 559 pacientes. La media del sistema de calificación APACHE II fue de 9.9 (DE 4). La prevalencia de mortalidad intrahospitalaria global fue de 6.1%. El mejor valor de corte de la calificación para predecir mortalidad fue de 12, con un área bajo la curva ROC de 0.92. Los pacientes con APACHE II ≥ 12 tuvieron significativamente mayor mortalidad, incidencia de BGC, ACV, sangrado quirúrgico y necesidad de diálisis. En un modelo multivariado, el sistema APACHE II se relacionó de modo independiente con mayor tasa de mortalidad intrahospitalaria (OR, 1.14; IC95%, 1.08-1.21; p < 0.0001)., Conclusiones: El sistema de clasificación APACHE II demostró ser un predictor independiente de mortalidad intrahospitalaria en pacientes que cursan el postoperatorio de cirugía cardíaca., Background and Objectives: The APACHE II score allows predicting in-hospital mortality in patients admitted to intensive care units. However, it is not validated for patients undergoing cardiac surgery, since it does not have a good discriminatory capacity in this clinical scenario. The aim of this study is to determine prognostic value of APACHE II score in postoperative of cardiac surgery., Materials and Methods: The study was performed using the cardiac surgery database. Patients undergoing surgery between 2017 and 2018, with APACHE II score calculated at the admission, were included. The ROC curve was used to determine a cut-off value The primary endpoint was in-hospital death. Secondary endpoints included low cardiac output (LCO), stroke, surgical bleeding, and dialysis requirement. A multivariable logistic regression model was developed to adjust to various variables of interest., Results: The study evaluated 559 patients undergoing cardiac surgery. The mean of APACHE II Score was 9.9 (SD 4). The prevalence of in-hospital death was 6.1%. The best prognostic cut-off value for the primary endpoint was 12, with a ROC curve of 0.92. Patients with an APACHE II score greater than or equal to 12 had significantly higher mortality, higher incidence of LCO, stroke, surgical bleeding and dialysis requirement. In a multivariate logistic regression model, the APACHE II score was independently associated with higher in-hospital death (OR, 1.14; 95CI%, 1.08-1.21; p < 0.0001)., Conclusions: The APACHE II Score proved to be an independent predictor of in-hospital death in patients undergoing postoperative cardiac surgery, with a high capacity for discrimination., (Copyright: © 2020 Permanyer.)

Non-HACEK Gram-negative bacilli are a rare cause of infective endocarditis. Epidemiological, diagnostic and prognostic aspects of this entity are little known, and there is limited experience. The aim of this study was to analyze the clinical, microbiological and in-hospital outcomes of non-HACEK Gram negative bacilli endocarditis and to compare them with those due to other microorganisms., (Copyright © 2018 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.)

Although randomized clinical trials have compared the short-term results of coronary revascularization with on-pump vs. off-pump, the long-term survival effect of off-pump coronary surgery has not been analyzed. The aim of this study was to compare the long-term survival of patients with coronary surgery with off-pump technique. All patients that underwent coronary revascularization from November 1996 to March 2015 were included (n = 4687). We analyzed the long-term survival and the incidence of cardiac events between patients who received off-pump coronary revascularization (n = 3402) against those revascularized with on-pump technique (n = 1285). The primary endpoint was defined as death from any cause. To reduce potential biases, risk-adjusted analysis was performed (propensity score). In-hospital mortality and during follow-up (10 years) for both groups were analyzed. The overall hospital mortality was 3.1%. A statistically significant difference between groups in favor of off-pump surgery was observed (2.3% vs. 5.2%, p < 0.0001). In the survival analysis, off-pump surgery proved to have similar long-term survival as on-pump surgery (off-pump vs. on-pump: 77.9% ± 1.2% vs. 80.2% ± 1.3%, p log rank = 0.361); even in the adjusted survival analysis (84.2% ± 2.9% vs. 80.3% ± 2.4%, p = 0.169). In conclusion, off-pump coronary surgery was associated with lower in-hospital mortality; and it was not associated with increased long-term survival compared with on-pump surgery.

Background: We studied long-term survival using bilateral internal thoracic artery (BITA) grafting in a T-configuration exclusively versus using single internal thoracic artery (SITA) grafting in patients with multivessel disease., Methods: Consecutive coronary operations performed at a single center between 1996 and 2014 were reviewed. Long-term survival among patients receiving coronary revascularization exclusively with BITA grafting in a T-configuration (n = 2,098) versus SITA grafts plus other types of conduits (saphenous vein graft [SVG] and radial artery [RA]) grafts (n = 1,659). In patients who underwent BITA grafting, the left internal thoracic artery (LITA) was grafted mainly to the left anterior descending artery, whereas the right internal thoracic artery (RITA) was used more commonly to graft the circumflex (Cx) artery and the right coronary system as T-grafts. A total of 485 pairs of patients were matched using propensity scores. Cox proportional hazard models were generated to examine the association of arterial BITA grafting with mortality., Results: Patients in the BITA group were more likely to be younger (BITA, 63.7 ± 9.1 versus SITA, 65.0 ± 9.9; p < 0.0001). At 30 days, patients who underwent BITA grafting experienced reduced unadjusted mortality (BITA, 1.2% versus SITA, 4.4%; p < 0.0001). At 10 years, patients who underwent BITA grafting experienced superior unadjusted survival (BITA, 82.6% ± 1.8% versus SITA, 76.1% ± 1.3%; p = 0.001). Cox regression analysis in the entire study cohort showed that BITA grafting was associated with improved survival (hazard ratio [HR], 0.71; 95% confidence interval [CI], 0.58-0.87; p < 0.001). In the propensity-score-adjusted analysis, patients who underwent BITA grafting had similar in-hospital mortality (BITA, 1.6% versus SITA, 2.9%; p = 0.196). Patients who underwent BITA grafting still showed improved survival at 10 years (BITA, 81.0% ± 4.1% versus SITA, 71.8% ± 2.5%; p = 0.039)., Conclusions: This study suggests that coronary artery operations exclusively with BITA grafting in a T-configuration may be associated with better long-term survival than grafting with SITA plus other types of conduits., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

We report a challenging case of a 32-year-old patient in New York Heart Association (NYHA) class IV with pulmonary atresia, ventricular septal defect, a left aortopulmonary collateral artery, a right modified Blalock-Taussing shunt, and a gigantic aneurysm of the ascending aorta with severe aortic valve insufficiency. A combined Rastelli and Bentall procedure was performed by a joint adult and pediatric cardiovascular surgery team. One year after the operation, the patient is in NYHA class I, working full time., (© The Author(s) 2014.)

Objective: The aim of our study was to evaluate the long-term outcome of patients exclusively undergoing total arterial revascularization off-pump coronary artery bypass grafting and to compare the performance of the radial artery and the right internal thoracic artery as a second conduit., Methods: We studied a consecutive series of 1700 patients undergoing off-pump coronary artery bypass grafting, receiving a radial artery or right internal thoracic artery as a second graft for total arterial revascularization, between 2003 and 2010. A total of 1447 patients (85.11%) received bilateral internal thoracic artery grafting, and 253 patients (14.89%) received left internal thoracic artery and radial artery grafting. A propensity score-matched analysis was performed to compare the 2 groups, bilateral internal thoracic artery and left internal thoracic artery and radial artery, relative to overall survival, morbidity, and combined end points event-free survival. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were estimated by Cox regression., Results: In the full unmatched patient population, the postoperative survival (HR, 0.59; 95% CI, 0.38-0.92; P = .021), incidence of reintervention/readmission (HR, 0.42; 95% CI, 0.28-0.61; P < .001), and combined end points (HR, 0.47; 95% CI, 0.35-0.63; P < .001) were significantly better in the bilateral internal thoracic artery group. In the propensity score-matched patient population, the incidence of reintervention/readmission (HR, 0.40; 95% CI, 0.18-0.88; P = .02) and combined end points (HR, 0.54; 95% CI, 0.32-0.92; P = .02) were significantly better in the bilateral internal thoracic artery group compared with the left internal thoracic artery-radial artery group., Conclusions: The results of our study provide evidence for the superiority of the right internal thoracic artery graft compared with the radial artery as a second conduit in total arterial revascularization off-pump coronary artery bypass grafting., (Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Azithromycin, a macrolide antibacterial, has been shown to modify the phenotype of macrophages. We have investigated whether azithromycin in vitro is able to modulate the differentiation of human blood monocytes to DCs. iA-DCs appear to have a unique phenotype, characterized by increased granularity, adherence, and a surface molecule expression profile similar to that of MDCs, namely, CD1a⁻CD14⁻CD71⁺CD209(high), as well as high CD86 and HLA-DR expression. The iA-DC phenotype is associated with increased IL-6 and IL-10 release, increased CCL2 and CCL18 expression and release, and M-CSF expression, as well as reduced CCL17 expression and release. Upon maturation with LPS, A-DCs and MDCs exhibit decreased expression of HLA-DR and costimulatory molecules, CD40 and CD83, as well as an increase in IL-10 and a decrease in CCL17 and CXCL11 secretion. These modulated responses of iA-DCs were associated with the ability to reduce a MLR, together with enhanced phagocytic and efferocytotic properties. Azithromycin, added 2 h before activation of iDCs with LPS, enhanced IL-10 release and inhibited IL-6, IL-12p40, CXCL10, CXCL11, and CCL22 release. In conclusion, azithromycin modulates the differentiation of blood monocyte-derived DCs to form iA-DCs with a distinct phenotype similar to that of iMDCs, accompanied by enhanced phagocytic and efferocytic capabilities. It also modifies LPS-induced DC maturation by decreasing surface molecule expression required for T cell activation, increasing IL-10 production, and inducing MLR-reducing properties.

Objective: The aim of our study was to evaluate the impact of recent clopidrogel use before off-pump coronary artery bypass grafting on the postoperative risk of bleeding., Methods: During the period January 2003 to December 2006, 1104 consecutive patients underwent off-pump coronary artery bypass grafting. Patients were divided into two groups according to the recent use of clopidrogel (within 7 days). We performed a propensity score to further adjust for differences between the patients with and without recent use of clopidrogel., Results: Mean age was 64 +/- 14 years and 87% were male. The clopidrogel group had a greater incidence of patients in unstable condition, requiring emergency coronary bypass grafting, and with a high EuroSCORE. Propensity score analysis selected 88 patients with and 176 without recent use of clopidrogel. By propensity score, the clopidrogel group had higher requirements for fresh frozen plasma units (18.1% vs 8.5%; P = .02), reoperation owing to bleeding (5.6% vs 0.5%; P = .009), and higher need for postoperative mechanical ventilation (4% vs 10%; P = .04), whereas mortality and length of stay were similar between groups., Conclusion: Recent use of clopidogrel before off-pump coronary artery bypass grafting is associated with greater risk for bleeding with similar mortality rate.

Background: This was a single-institutional study about total arterial off-pump coronary artery bypass graft surgery (OPCABG) using bilateral internal thoracic arteries in triple-vessel disease., Methods: We retrospectively reviewed the records of 569 multivessel CABG patients (10% female) who underwent total arterial (bilateral internal thoracic arteries) OPCABG between January 2002 and December 2006. Mean age was 63.9 +/- 8.9 years. All patients included underwent OPCABG as an elective procedure. Postoperative angiograms were evaluated during a postoperative follow-up period. Early and midterm outcomes, including overall patient survival, freedom from readmission and reintervention, freedom from the combined endpoint of cardiac events and quality of life, were evaluated. Multivariate analysis was used to find determinants of late death. Overall survival and freedom from combined endpoints were determined by the Kaplan-Meier method., Results: The average number of distal anastomoses per patient was 3.18 +/- 0.4. The average operation time was 209.7 +/- 41.7 minutes. Thirty-day mortality was 0.88% (5 of 569). Overall patency rate for all grafts studies was 94.3% (632 of 670). Mean follow-up time was 810 days (range, 8 days to 61 months). Cumulative patient survival at 4 years was 93.3% +/- 1.9%. Significant predictors of late mortality were age (hazard ratio, 1.06; 95% confidence interval: 1.01 to 1.12), previous stroke (hazard ratio, 6.5; 95% confidence interval: 1.8 to 23.5), and moderate to severe left ventricle ejection fraction (hazard ratio, 3.3; 95% confidence interval: 1.2 to 8.8). Freedom from hospital readmission and reintervention at 4 years was 91.7% +/- 3.5%. Freedom from combined endpoint (death, hospital readmission, and reintervention) at 4 years was 86.9% +/- 3.6%. There was a marked improvement in patients' quality of life at follow-up (Duke Activity Status Index score > 45 in more than 70% patients)., Conclusions: Total arterial (bilateral internal thoracic arteries) OPCABG is feasible with a safe outcome in terms of hospital mortality. At follow-up the incidence of death, hospital readmission and reintervention and patients' quality of life are acceptable with favorable graft patency rates.

Although alkaline phosphatase (APase) from Escherichia coli crystallizes as a symmetric dimer, it displays deviations from Michaelis-Menten kinetics supported by a model describing a dimeric enzyme with conformationally and kinetically non-equivalent subunits. The proposed model, explaining the mechanism of substrate hydrolysis, encompasses a conformational change mediated by subunit interactions [S. Orhanović, M. Pavela-Vrancic, Eur. J. Biochem. 270 (2003) 4356-4364]. The significance of interactions at the subunit interface and the involvement of the beta-pleated sheet stretching from underneath the active site to the subunit surface, in the catalytic mechanism, has been probed by site-directed mutagenesis. The mutant APase, carrying alanine in place of Thr81, was analyzed in comparison to the wild-type protein. The T81A mutation, introduced at the subunit interface, significantly affected the protein kinetic properties, emphasizing the importance of subunit interactions in the catalytic process.

Tyrocidine synthetase 1 (TY1), the initial monomodular constituent of the tyrocidine biosynthetic system, exhibits relaxed substrate specificity, however an efficient editing of the mis-activated amino acid provides for fidelity of product formation. We chose to analyse the consequence of single amino acid substitutions, in the amino acid activation site of apo-TY1, on the editing functions of the enzyme. Discrimination between L-Phe and D-Phe by apo-TY1 depends primarily on the editing reaction. Distraction of unnatural amino acid substrates, such as L-PheSer, implies that editing is not designated to select a specific mis-activated amino acid, but instead to discriminate all mis-activated amino acid analogues. It was shown that active site residues which interact with the adenylate are essential for both activation and editing. Substitution of Lys186 with arginine substantially reduces the editing capacity of the protein. Loss of amino acid discrimination ability by the apo-K186T and apo-R416T mutant proteins suggests a role of active site residues in maintaining the structural determinants for substrate selection. Inadequate conformational changes, induced by non-cognate amino acid substrates, promote ATP breakdown yielding P(i) and ADP. Replacement of residue Lys186 or Arg416 enhances ATP hydrolysis implying a role in binding or adjusting of the triphosphate chain for adenylate formation and pyrophosphate cleavage.

Alkaline phosphatase (AP) displays significant structural changes during metal-ion binding, supporting cooperative interactions between the subunits of the dimeric enzyme. Here, we present data on the dynamic properties of AP from E. coli, and characterize the structural changes that accompany variations in metal-ion content, combining limited proteolysis and MALDI-TOF mass spectrometry. Limited proteolysis revealed an internal cleavage site at Arg-293, reflecting a position of conformational flexibility supporting subunit communication essential for catalysis. A specific shielding of a region distant from the metal-binding site has been demonstrated, implying transmission of conformational changes, induced by metal-ion binding to the adjacent subunit, across the subunit interface.