Histological examination of explanted tissue-engineered bovine pericardium following heart valve repair.

OBJECTIVES: Our goal was to present histopathological findings of human explants of a tissue-engineered bovine pericardium CardioCel (Admedus Regen Pty Ltd, Malaga, WA, Australia) used for heart valve repair in patients with congenital and acquired heart valve disease. METHODS: Sixty patients underwent heart valve repair from May 2014 to November 2018 using CardioCel as a substitute for valve tissue. We identified 9 cases in which the CardioCel patch was explanted following valve repair and available for histomorphological analyses. CardioCel explants were evaluated histologically using haematoxylin and oeosin, Elastica van Gieson and immunohistochemical stains. RESULTS: The indications for explantation were related to the CardioCel patch in 6 patients. Median time between the implantation and explantation was 242 (range 3-1247) days. We demonstrated a characteristic remodelling pattern with superficial coating of the tissue-engineered bovine pericardium by granulation tissue composed of histiocytes, few lymphocytes and fibrin. We had 2 cases with a multifocal nodular disruption, fragmentation and sclerosis of the decellularized collagen matrix with focal calcification after 795 and 1247 days in situ. CONCLUSIONS: Our data suggest that the tissue-engineered CardioCel patch is initially tolerated in the valvular position in the majority of patients. However, we also experienced graft failures that showed degeneration with fragmentation of the collagen matrix and even 2 cases with focal calcification evident from the histopathological analysis. Further analyses of mid- and long-term performance are mandatory.

"Blame it on the Comorbidities": A 5-Year Follow-Up of 53 Chronic Dialysis-Dependent Patients Who Underwent Cardiac Surgery.

Objectives This study evaluates midterm survival rates and risk factors for mortality of chronic dialysis-dependent patients undergoing cardiac surgery. Methods Fifty-three dialysis-dependent patients (34 males, aged 67 ± 12 years) with end-stage renal disease operated within March 2007 and May 2012 were analyzed retrospectively. Survival rates were calculated using Kaplan-Meier methods. Predictors of midterm survival were identified with multivariate Cox-regression analysis. Results Twenty-three patients received isolated coronary artery bypass graft surgery, 17 received isolated valve replacement, and 13 received combined procedures. Thirty-day mortality was 24.5% (n = 13). Follow-up was complete for 94.3% (n = 50). Survival rates at 1, 3, and 5 years were: 82, 50, and 17%, respectively. Neither age, gender, poor ejection fraction, emergency, ECC/X-clamp (cross-clamp) time, nor use of left internal thoracic artery or right internal thoracic artery had any influence on midterm survival. Causes of death within midterm follow-up period were related to cardiac events in 16% and neurological events in 16%. In the majority (47%), cause of death was associated with peripheral arterial disease (PAD).The only comorbidity, which could be identified as a significant risk factor, was PAD (p = 0.035). Five patients underwent successful renal transplantation within the follow-up period. Conclusion Although 30-day mortality in this high-risk patient population was increased, midterm survival rates were comparable to the results described in the literature. Cause of death within midterm follow-up period was mostly noncardiac related. Given the limited number of patients, predictors for enhanced 30-day mortality, such as preoperative myocardial infarction, prolonged extracorporeal circulation, operation time, and diabetes mellitus, did not have an influence on midterm survival.

Does Bilateral ITA Grafting Increase Perioperative Complications? Outcome of 6,476 Patients with Bilateral versus 5,020 Patients with Single ITA Bypass.

OBJECTIVES: Despite the superior patency of internal thoracic artery (ITA) grafting compared with saphenous veins, frequency of bilateral ITA (BITA) grafting in Europe is still approximately 10%. The aim of the present study was to compare the early outcome of patients receiving either BITA or single ITA (SITA) grafting. METHODS: A total of 11,496 patients with isolated coronary artery bypass grafting (CABG), operated between January 1996 and December 2012, were analyzed retrospectively; 0.6476 patients (mean age 65.2 years, 81.3% males) received BITA and 5,020 patients (mean age 66.6 years, 76.7% males) SITA grafting. Mean body mass index (BMI) was 27.2 versus 27.4, p = 0.017. Incidence of diabetes was 28.9 versus 28.4%, p = 0.08. Ejection fraction (EF) > 50 was 71.3% (BITA) versus 66.3% (SITA), p < 0.001. Elective operations were performed in 88.4% (BITA) versus 83.3% (SITA), and urgent/emergent surgery was necessary in 11.6% (BITA) versus 16.7% (SITA), p < 0.001. RESULTS: Number of grafts was 3.76 (BITA) versus 3.06, p < 0.001. Duration of surgery (194.4 vs. 180.4 minutes) as well as X-clamp time (60.4 vs. 51.7 minutes) was prolonged for BITA, p < 0.001. Perioperative infarction rate revealed 3.2% (BITA) versus 3.6%, p = 0.54. Frequency of rethoracotomy due to bleeding was higher in the BITA group (3.8 vs. 2.1%), p < 0.001. Sternal instabilities occurred in 2.3% (BITA) versus 2.2%, p = 0.749. Duration of mechanical ventilation < 12 hours was 74.6 versus 77.1%, p = 0.09 and duration of in-hospital stay was 10.5 versus 10.4 days, p = 0.68. Thirty-day mortality was 2.4% (BITA) versus 3.0%, p = 0.09. Multivariate analysis identified prolonged duration of surgery, BMI > 30, emergent operations, advanced age, and BITA grafting as predictor for sternal instabilities. EF < 30%, advanced age plus emergency were associated with increased 30-day mortality. CONCLUSION: CABG using BITA can be performed routinely with good clinical results and low mortality. Compared with SITA grafting, bleeding complications were enhanced.

High-Risk Cardiac Surgery in Patients with Intravenous Drug Abuse and/or Active Hepatitis C or HIV Infection: An Ethical Discussion of Six Cases.

OBJECTIVES: To discuss the dilemma of adequate decision making in patients with intravenous drug abuse and recurrent valve prosthesis infections or in patients with positive HIV or hepatitis C status. Ethical, social, and economic considerations, not only in terms of technical feasibility but also in terms of unpromising results and aspects of resources, are discussed. Thoughts are presented about the legitimation of cardiac surgery centers refusing to perform surgery in high-risk patients with HIV or hepatitis C infections. METHODS: Presentation of six cases for discussion. Three patients were addicted to intravenous drugs and had recurrent prosthetic valve endocarditis, and the other three patients had either paravalvular leakage of a mitral valve prosthesis or acute aortic dissection or coronary artery disease. Five of these patients suffered from HIV/AIDS and infective hepatitis C. Four of these patients were refused by other centers due to high risk or a lack of capacity. RESULTS: All six patients were operated during 2013. Mortality was 17%. CONCLUSION: Decision making in noncompliant drug addicts with recurrent prosthesis infection and in HIV-positive patients leads beyond surgical challenges to ethical and economic considerations.

Performance of EuroSCORE II compared to EuroSCORE I in predicting operative and mid-term mortality of patients from a single center after combined coronary artery bypass grafting and aortic valve replacement.

OBJECTIVE: The performance comparison of the recently introduced European System for Cardiac Operative Risk Evaluation II in predicting operative as well as mid-term mortality, with its previous version in patients after combined aortic valve replacement and coronary artery bypass grafting surgery. METHODS: This retrospective analysis included 216 patients operated on at one institution from 01/1999 to 12/2005. Accuracy and calibration of EuroSCORE I and II were assessed by plotting the areas under the receiver operator curves and comparing observed and predicted mortalities. RESULTS: EuroSCORE II showed, regarding early mortality, a slightly higher discriminatory accuracy with an area under the receiver operator curve of 0.77, while additive and logistic EuroSCORE I areas were 0.749, 0.75, respectively. The highest specificity and sensitivity level was approached for EuroSCORE II at a predicted mortality of 4.4 %. Receiver operator curves concerning mid-term mortality revealed areas for additive, logistic EuroSCORE and EuroSCORE II of 0.745, 0.739 and 0.718 with the highest accuracy levels at predicted mortalities of 6.5, 6.48 and 3.88 %, respectively. Mean predicted mortalities by logistic EuroSCORE and EuroSCORE II were 8.35 and 3.99 %, respectively, while overall observed operative mortality was 6.3 %. In "high-risk" patients (EuroSCORE > 13), EuroSCORE II underestimated early and mid-term outcomes. CONCLUSIONS: Regarding operative mortality, EuroSCORE II showed in this study a slightly higher discriminatory accuracy than EuroSCORE I. There were no significant differences in the calibration of the two model versions in "low-" and "moderate-risk" patients regarding early as well as mid-term mortality. Analyses in larger patient populations will contribute to further model improvement.

Applying the Gender Lens to Risk Factors and Outcome after Adult Cardiac Surgery.

BACKGROUND: Applying the gender lens to risk factors and outcome after adult cardiac surgery is of major clinical interest, as the inclusion of sex and gender in research design and analysis may guarantee more comprehensive cardiovascular science and may consecutively result in a more effective surgical treatment as well as cost savings in cardiac surgery. METHODS: We have reviewed classical cardiovascular risk factors (diabetes, arterial hypertension, hyperlipidemia, smoking) according to a gender-based approach. Furthermore, we have examined comorbidities such as depression, renal insufficiency, and hormonal influences in regard to gender. Gender-sensitive economic aspects have been evaluated, surgical outcome has been analyzed, and cardiovascular research has been considered from a gender perspective. RESULTS: The influence of typical risk factors and outcome after cardiac surgery has been evaluated from a gender perspective, and the gender-specific distribution of these risk factors is reported on. The named comorbidities are listed. Economic aspects demonstrated a gender gap. Outcome after coronary and valvular surgeries as well as after heart transplantation are displayed in this regard. Results after postoperative use of intra-aortic balloon pump are shown. Gender-related aspects of clinical and biomedical cardiosurgical research are reported. CONCLUSIONS: Female gender has become an independent risk factor of survival after the majority of cardiosurgical procedures. Severely impaired left ventricular ejection fraction independently predicts survival in men, whereas age does in females.

Cardiac surgery in dialysis-dependent patients: impact of gender on early outcome in single-center experience with 204 consecutive cases.

BACKGROUND: This study evaluates the impact of gender in dialysis-dependent patients undergoing cardiac surgery. METHODS: We retrospectively identified 204 dialysis-dependent patients (68.6% male, aged 66.6 ± 9.9 years) with end-stage renal disease undergoing cardiac surgery and compared them to a propensity-score-pair-matched control collective. RESULTS: A 30-day mortality was 13.2% (14/106) for coronary artery bypass grafting (CABG), 19.3% (6/31) for aortic valve replacement (AVR), and 23.8% (16/67) for combined procedures. Postoperative chest tube output was significantly higher in men (1,007 ± 946 mL) versus women (687 ± 598 mL, p = 0.014). Compared with a propensity-score-pair-matched control collective of 204 patients, we identified significant differences in terms of 30-day mortality: overall mortality revealed 17.6 versus 4.6% (p = 0.0001), 13.2 versus 3.4% (p = 0.014) for CABG, 19.3 versus 0% (p = 0.051) for AVR, and 23.8 versus 9.1% (p = 0.02) for combined procedures. CONCLUSION: Multivariate analysis identified preoperative myocardial infarction, prolonged extracorporeal circulation time, operation time, and surgical reexploration as independent predictors of 30-day mortality. There was a higher occurrence of bleeding complications in men that remained significant even after correction for body surface area.