External validation of the REMEMBER score.

Background: The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) after coronary artery bypass grafting (CABG) is associated with high in-hospital mortality rates. The pRedicting mortality in patients undergoing venoarterial Extracorporeal MEMBrane oxygenation after coronary artEry bypass gRafting (REMEMBER) score has been created to predict in-hospital mortality in this subgroup of patients. The aim of this study is to externally validate the REMEMBER score. Methods: All CABG patients who received VA-ECMO during or after the operation at our center between 01/2012 and 12/2021 were included in the analysis. Discrimination was assessed using concordance statistics, visualized by ROC curve analysis. Calibration-in-the-large and Calibration slope were tested separately. Results: A total of 107 patients (male: n = 78, 72.9%) were included in this study. The in-hospital mortality rate in our cohort was 45.8% compared with 55% in the original study. The REMEMBER score median predicted mortality rate was 52% (76.9-36%). However, the REMEMBER score showed low discriminative ability [AUC: 0.623 (p = 0.0244; 95% CI = 0.524-0.715)] and inaccurate calibration (intercept = 0.25074; p = 0.0195; slope = 0.39504; p = 0.0303), indicating poor performance. Conclusions: The REMEMBER score did not predict in-hospital mortality and was therefore not applicable in our cohort of patients. Additional external validation studies in a multicenter setting are therefore advisable.

Grafts and Patches: Optimized but Not Optimal Materials for Congenital Heart Surgery.

A variety of materials are available for the surgery of children with congenital heart defects. In addition to growth-related mismatch, degeneration of the material in particular frequently leads to reoperation. Therefore, the choice of conduits and patches should be made carefully. This article provides an overview of the most commonly implanted materials in pediatric cardiac surgery.Structural changes can be detected in all available materials. Depending on the age at implantation and the site of implantation, the extent and time course of material degeneration vary. Autologous material is still the gold standard in reconstructive surgery. Biological materials have largely replaced artificial materials in clinical use.The search for the ideal material continues. In pediatric cardiac surgery, there are only optimized but no optimal materials.

In-Hospital Mortality and Risk Prediction in Minimally Invasive Sutureless versus Conventional Aortic Valve Replacement.

Objective. Available evidence suggests that a minimally invasive approach with the use of sutureless bioprostheses has a favorable impact on the outcome of patients undergoing aortic valve replacement (AVR). Methods. From 2010 to 2019, 2732 patients underwent conventional AVR through median sternotomy with a stented bioprosthesis (n = 2048) or minimally invasive AVR with a sutureless bioprosthesis (n = 684). Results. Using the propensity score, 206 patients in each group were matched, and the matched groups were well balanced regarding preoperative risk factors. Both unmatched and matched patients of the sutureless + minimally invasive group showed significantly shorter cross-clamp times and longer ICU stay. In-hospital mortality was the only outcome measure that was confirmed in both analyses, and was higher in the stented + conventional group (2.54% and 2.43% in unmatched and matched patients, respectively) compared with the sutureless + minimally invasive group (0.88% and 0.97% in unmatched and matched patients, respectively) (p = 0.0047 and p < 0.0001, respectively). No differences in postoperative pacemaker implantation were recorded in matched patients of both groups (n = 2 [1%] in the stented + conventional group vs. n = 4 [2%] in the sutureless + minimally invasive group; p = 0.41). The discrimination power of EuroSCORE II was not confirmed in the sutureless + minimally invasive group, yielding an area under the ROC curve of 0.568. Conclusions. Minimally invasive sutureless AVR has a favorable impact on the immediate outcome and is associated with significantly lower in-hospital mortality rates compared with conventional AVR, resulting in the absence of the discrimination power of EuroSCORE II for predicting AVR outcomes.

Industrial Processing Induces Pericardial Patch Degeneration.

Background: Autologous pericardium is considered gold standard for various reconstructive surgical procedures in children. However, processed bovine, equine, and porcine pericardial tissue are also widely used. We investigated structural differences and analyzed alterations caused by industrial processing. Additionally human and equine pericardium explants, used during aortic valve reconstruction were analyzed. Methods: Pericardial tissues (native, processed and explanted) were gathered and stained with HE and EvG to visualize collagen as well as elastic fibers. Fiber structures were visualized by light and polarization microscopy. Antibody staining against CD 3, CD 20, and CD 68 was performed to identify inflammation. Results: Native pericardium of different species showed small differences in thickness, with bovine pericardium being the thickest [bovine: 390 µm (± 40.6 µm); porcine: 223 µm (± 30.1 µm); equine: 260 µm (± 28.4 µm)]. Juvenile pericardium was 277 µm (± 26.7 µm). Single collagen bundle diameter displayed variations (~3-20 µm). Parallel collagen fibers were densely packed with small inter-fibrillary space. After industrial tissue processing, loosening of collagen network with inter-fibrillary gapping was observed. Pericardium appeared thicker (mean values ranging from 257-670 µm). Processed tissue showed less birefringence under polarized light. All analyzed tissues showed a small number of elastic fibers. Fibrosis, calcification and inflammatory processes of autologous and equine pericardium were observed in patient explants. Conclusion: None of the analyzed tissues resembled the exact structure of the autologous pericardial explant. Degeneration of pericardium starts during industrial processing, suggesting a potential harm on graft longevity in children. A careful surgical approach prior to the implantation of xenografts is therefore needed.

Comparison between the age, creatinine and ejection fraction II score and the European System for Cardiac Operative Risk Evaluation II: which score for which patient?

OBJECTIVES: Each surgical risk prediction model requires a validation analysis within a large 'real-life' sample. The aim of this study is to validate the age, creatinine and ejection fraction (ACEF) II risk score compared with the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II. METHODS: All patients operated on at 8 Italian cardiac surgery centres in the period 2009-2019 with available data for the calculation of EuroSCORE II and ACEF II were included in the study. Mortality was recorded and receiver operating characteristic curves were plotted for the overall study population and for different patient subgroups according to the type of surgery. RESULTS: A total of 14 804 patients were enrolled [median age of 70 (62-77) years, 35.4% female], and among these, 3.1% underwent emergency surgery. Thirty-day mortality was 2.84% (n = 420). In the total population, the area under the curve with EurosCORE II was significantly higher than that recorded with ACEF II [0.792, 95% confidence interval (CI) 0.79-0.8 vs 0.73, 95% CI 0.73-0.74; P < 0.001]. This finding was also confirmed in the patient subgroups undergoing isolated valve surgery (EuroSCORE II versus ACEF II: 0.80, 95% CI 0.79-0.814 vs 0.74, 95% CI 0.724-0.754; P = 0.045) or isolated aortic surgery (0.754, 95% CI 0.70-0.79 vs 0.53, 95% CI 0.48-0.58; P = 0.002). In contrast, the 2 scores did not differ significantly in patients undergoing isolated bypass surgery (0.8, 95% CI 0.78-0.81 vs 0.77, 95% CI 0.75-0.78; P = 1). CONCLUSIONS: In both the overall population and patient subgroups, EuroSCORE II proved to be more accurate than ACEF II. However, in patients undergoing bypass surgery, ACEF II proved to be an easy and simple to use risk score, demonstrating comparable risk prediction performance with the more complex EuroSCORE II.

Surgical treatment of valve endocarditis in high-risk patients and predictors of long-term outcomes.

Infective endocarditis represents a surgical challenge associated with perioperative mortality. The aim of this study is to evaluate the predictors of operative mortality and long-term outcomes in high-risk patients. We retrospectively analyzed 123 patients operated on for infective endocarditis from January 2011 to December 2020. Logistic regression model was used to identify prognostic factors of in-hospital mortality. Long term follow-up was made to asses late prognosis. Preoperative renal failure, an elevation EuroSCORE II and prior aortic valve re-replacement were found to be preoperative risk factors significantly associated with mortality. In-hospital mortality was 27% in patients who had previously undergone aortic valve replacement (n = 4 out of 15 operated, p = 0.01). Patients who were operated on during the active phase of infective endocarditis showed a higher mortality rate than those operated on after the acute phase (16% vs. 0%; p = 0.02). The type of prosthesis used (biological or mechanical) was not associated with mortality, whereas cross-clamp time significantly correlated with mortality (mean cross-clamp time 135 ± 65 min in dead patients vs. 76 ± 32 min in surviving patients; p = 0.0005). Mean follow up was 57.94 ± 30.9 months. Twelve patients died (11.65%). Among the twelve mortalities, five were adjudicated to cardiac causes and seven were non-cardiac (two cancers, one traumatic accident, one cerebral hemorrhage, two bronchopneumonia, one peritonitis). Overall survival probability (freedom from death, all causes) at 3, 5, 7 and 8 years was 98.9% (95% CI 97-100%), 96% (95% CI 92-100%), 85.9% (95% CI 76-97%), and 74% (95% CI 60-91%) respectively. Our study demonstrates that an early surgical approach may represent a valuable treatment option for high-risk patients with infective endocarditis, also in case of prosthetic valve endocarditis. Although several risk factors are associated with higher mortality, no patient subset is inoperable. These findings can be helpful to inform decision-making in heart team discussion.

Elastica degeneration and intimal hyperplasia lead to Contegra® conduit failure.

OBJECTIVES: Currently, Contegra® grafts (processed bovine jugular vein conduits) are widely used for reconstructive surgery of the right ventricular outflow tract in patients with congenital heart disease (CHD). We analysed explanted Contegra conduits from 2 institutions histologically to get a possible hint at the underlying pathomechanisms of degenerative alterations and to find histological correlations of graft failure. Additionally, we compared the explants with a non-implanted processed graft and a native jugular vein obtained from a young bull. METHODS: The explanted Contegra grafts were gathered during reoperations of 13 patients (male: n = 9, 69.2%; female: n = 4, 30.8%). After standardized histological preparation, samples were stained with dyes haematoxylin and eosin and Elastica van Gieson. Additionally, X-ray pictures revealed the extent of calcification and chelaplex (III)-descaling agent was used to decalcify selected explants. RESULTS: Processing of the native jugular vein leads to tissue loosening and a loss of elastic fibres. For graft failure after implantation, 2 pathomechanisms were identified: original graft alteration as well as intimal hyperplasia. Elastica degeneration and rearrangement with interfibrillary matrix structures were the main developments observed within the graft itself. Intimal hyperplasia was characterized by fibrous tissue apposition, calcification and heterotopic ossification. CONCLUSIONS: Regression of the elastic fibre network leads to rigidification of the conduit. In Contegra grafts, atherosclerosis-like changes can be considered the leading cause of graft stenosis and insufficiency. We conclude that both observed mechanisms lead to early reoperation in CHD patients.