Bacterial Spectrum and Infective Foci in Patients Operated for Infective Endocarditis: Time to Rethink Strategies?

OBJECTIVE: The rising incidence of infective endocarditis (IE) accompanied by the de-escalation of antibiotic prophylaxis and the complexity of surgical treatment makes IE a daunting foe. We reviewed all patients who underwent cardiac surgery for IE at our institution with a focus on causative organisms and infective foci. METHODS: A review of 3,952 consecutive patients who underwent cardiac surgery at our institution between January 2013 and December 2017 revealed 160 patients (4%) who were operated for IE. RESULTS: The predominantly affected valves were the aortic (30%) and mitral valve (26.9%) as well as a combination of both (8.8%). A total of 28.8% of patients suffered from prosthetic valve endocarditis (PVE). The most frequently identified causative organisms were Staphylococcus (45.7%), Streptococcus (27.5%), and Enterococcus species (16.7%), which was predominantly associated with PVE (p = 0.050). In 13.1% of patients, a causative organism has not been detected. The most frequent infective foci were dental (15%), soft-tissue infections (15%), spondylodiscitis (10%), and infected intravascular implants (8.8%). Relevant predisposing factors were immunosuppression (9.4%) and intravenous drug abuse (4.4%). Septic cerebral infarctions were diagnosed in 28.8% of patients. Postoperative mortality was 22.5%. CONCLUSIONS: As the bacterial spectrum and the infective foci are still the "old acquaintances," and with regard to the increasing incidence of IE, current risk-benefit evaluations concerning antibiotic prophylaxis may need to be revisited.

[Current status of transplantation medicine in the field of heart and lung transplantation : Legal regulations and clinical implementation]. / Aktueller Stand der Transplantationsmedizin im Bereich Herz- und Lungentransplantation : Gesetzliche Rahmenbedingungen und klinische Umsetzung.

Transplantation medicine in Germany is clearly structured and strictly regulated. In recent years, various legal changes have been implemented to improve organ donation. Nevertheless, the restricted availability of donor organs remains the main limitation of the treatment, also in the field of heart and lung transplantation. Both procedures have now become established treatment options for selected patients with end-stage organ failure. The aim is to improve the quality of life as well as survival. The success of the treatment largely depends on the selection of suitable recipients as well as optimal perioperative and postoperative management including a lifelong specialized follow-up. The complexity of the treatment requires a high degree of specialized knowledge and skills. This article summarizes the current state of transplantation medicine of thoracic organs with a focus on the new additional subspecialty of transplantation medicine.

[Current status of transplantation medicine in the field of heart and lung transplantation]. / Aktueller Stand der Transplantationsmedizin im Bereich Herz- und Lungentransplantation: Gesetzliche Rahmenbedingungen und klinische Umsetzung.

Transplantation medicine in Germany is clearly structured and strictly regulated. In recent years, various legal changes have been implemented to improve organ donation. Nevertheless, the restricted availability of donor organs remains the main limitation of the treatment, also in the field of heart and lung transplantation. Both procedures have now become established treatment options for selected patients with end-stage organ failure. The aim is to improve the quality of life as well as survival. The success of the treatment largely depends on the selection of suitable recipients as well as optimal perioperative and postoperative management including a lifelong specialized follow-up. The complexity of the treatment requires a high degree of specialized knowledge and skills. This article summarizes the current state of transplantation medicine of thoracic organs with a focus on the new additional subspecialty of transplantation medicine.

The effect of perioperative hemadsorption in patients operated for acute infective endocarditis-A randomized controlled study.

Patients operated for infective endocarditis (IE) are at high risk of developing an excessive systemic hyperinflammatory state, resulting in systemic inflammatory response syndrome and septic shock. Hemoadsorption (HA) by cytokine adsorbers has been successfully applied to remove inflammatory mediators. This randomized controlled trial investigates the effect of perioperative HA therapy on inflammatory parameters and hemodynamic status in patients operated for IE. A total of 20 patients were randomly assigned to either HA therapy or the control group. HA therapy was initiated intraoperatively and continued for 24 hours postoperatively. Cytokine levels (IL-6, IL-1b, TNF-α), leukocytes, C-reactive protein (CRP), and Procalcitonin (PCT) as well as catecholamine support, and volume requirement were compared between both groups. Operative procedures included aortic (n = 7), mitral (n = 6), and multiple valve surgery (n = 7). All patients survived to discharge. No significant differences concerning median cytokine levels (IL-6 and TNF-α) were observed between both groups. CRP and PCT baseline levels were significantly higher in the HA group (59.5 vs. 26.3 mg/dL, P = .029 and 0.17 vs. 0.05 µg/L, P = .015) equalizing after surgery. Patients in the HA group required significantly higher doses of vasopressors (0.093 vs. 0.025 µg/kg/min norepinephrine, P = .029) at 12 hours postoperatively as well as significantly more overall volume replacement (7217 vs. 4185 mL at 12 hours, P = .015; 12 021 vs. 4850 mL at 48 hours, P = .015). HA therapy did neither result in a reduction of inflammatory parameters nor result in an improvement of hemodynamic parameters in patients operated for IE. For a more targeted use of HA therapy, appropriate selection criteria are required.

Diagnostic Value of Cholinesterase Activity for the Development of Postoperative Delirium after Cardiac Surgery.

BACKGROUND: Depression of cholinesterase (CHE) activity has been reported to lead to an amplified neuroinflammatory response, which clinically manifests as postoperative delirium (PD). This observational study investigates the association between CHE activity and the development of PD following elective cardiac surgery. METHODS: Patients with preexisting neurologic deficits or carotid artery disease as well as patients undergoing reoperations or procedures under circulatory arrest have been excluded from this study. The Mini-Mental State Examination, the Confusion Assessment Method for the Intensive Care Unit, and the Intensive Care Delirium Screening Checklist were performed at regular intervals. CHE activity was estimated pre- and postoperatively until postoperative day (POD) 5 and at discharge. RESULTS: A total of 107 patients were included. PD was diagnosed in 34 (31.8%) patients, who have been compared with those without PD. Time on ventilator, length of ICU, and hospital stay were longer in patients with PD (p = 0.001, p < 0.001, and p = 0.004, respectively). MMSE scores were lower in patients with PD (p < 0.001; p = 0.015). CHE activity on POD 1 to 4 as well as at discharge were lower in the delirium group (p = 0.041; p = 0.029; p = 0.015; p = 0.035; p = 0.028, respectively). A perioperative drop of CHE activity of more than 50% and a postoperative CHE activity below 4,800 U/L (on POD 0) were independently associated with an increased risk of development of PD (p = 0.038; p = 0.008, respectively). CONCLUSION: In addition to the established functional tests, routine estimation of CHE activity may serve as an additional diagnostic tool allowing for the timely diagnosis and treatment of PD in cardiac surgery patients.

Safety and efficacy of digital chest drainage units compared to conventional chest drainage units in cardiac surgery.

OBJECTIVES: The use of digital chest drainage units (CDUs) has become increasingly common in thoracic surgery due to several advantages. However, in cardiac surgery, its use is still limited in favour of conventional analogue CDUs. In order to investigate the potential benefit of digital CDUs in cardiac surgery, we compared the safety and efficacy of both systems in patients undergoing cardiac surgery at our centre. METHODS: We retrospectively investigated 265 consecutive patients who underwent cardiac surgery at our institution between June 2017 and October 2017. These patients were divided into 2 groups: patients with analogue (A, n = 65) and digital CDUs (D, n = 200). Postoperative outcome was analysed and compared between both groups. In addition, the 'user experience' was evaluated by means of a questionnaire. RESULTS: The median age of the cohort was 70 years (P = 0.167), 25.3% of patients were female (P = 0.414). There were no differences in terms of re-explorative surgery or use of blood products. Nor was there a difference in the overall amount of fluid collected. However, during the first 6 h, more fluid was collected by the digital CDUs. The overall rate of technical failure was 0.4%. We observed a significantly higher rate of clotting in the tubing system of the digital CDUs (P = 0.042). Concerning the user experience, the digital CDUs were associated with a more favourable ease of use on the regular wards (P < 0.001). With regard to the overall user experience, the digital CDUs outperformed the analogue systems (P = 0.002). CONCLUSIONS: Digital CDUs can be safely and effectively applied in patients after cardiac surgery. Due to the improved patient mobility and simplified chest tube management, the use of digital CDUs may be advantageous for patients after cardiac surgery. However, the issue of clotting of the tubing systems should be addressed by further technical improvements.

Complex Valve Surgery in Elderly Patients: Increasingly Necessary and Surprisingly Feasible.

OBJECTIVES: The increasing proportion of elderly patients in cardiac surgery poses additional challenges for the clinical management and leads to a higher operative risk due to multiple comorbidities of these patients. We reviewed the outcome of patients who were 75 years and older and underwent complex multiple valve surgery at our institution. METHODS: A retrospective review was performed to identify patients who were 75 years and older and underwent multiple valve surgery between January 2011 and May 2016 at our institution. Patients were assigned to one out of four subgroups: combined aortic and mitral valve surgery (group AM), aortic and tricuspid valve surgery (group AT), mitral and tricuspid valve surgery (group MT), and aortic, mitral, and tricuspid valve surgery (group AMT). RESULTS: A total of 311 patients underwent multiple valve surgery, of whom 119 (38.3%) were 75 years and older (median: 78 [25th-75th quartile: 76-80]). The estimated operative mortality (EuroSCORE II) in the overall cohort was 10.7%. The observed 30-day mortality was 4.2% (7% in group AM, 0% in group AT, 2.2% in group MT, 3.8% in group AMT; p = 0.685). Main complications were reexplorative surgery in 16%, adverse cerebrovascular events in 6.7%, prolonged mechanical ventilation in 10.1%, renal replacement therapy in 15.1%, nosocomial pneumonia in 15.1%, and pacemaker implantation in 18.5%. CONCLUSIONS: This study demonstrates the feasibility of complex multiple valve surgery in elderly patients. The observed perioperative mortality was lower than predicted. However, we observed a substantial rate of adverse events; therefore, careful patient selection is required in this high-risk patient population.

Turning Things Around: The Role of Prone Positioning in the Management of Acute Respiratory Failure After Cardiac Surgery.

OBJECTIVES: The aim of this study was to determine the benefit of prone positioning (PP) in patients developing acute respiratory failure (ARF) after cardiac surgery. DESIGN: A retrospective analysis. SETTING: Review of the institutional database between October 2016 and October 2018 revealed 24 patients who underwent PP for the treatment of ARF after cardiac surgery. PARTICIPANTS: The authors found 24 patients who underwent PP for the treatment of ARF after cardiac surgery. This included 10 patients who required extracorporeal membrane oxygenation (ECMO) therapy. Among them, 6 patients with simultaneous PP and ECMO therapy. INTERVENTIONS: Data were collected at the time of PP, 6 hours after PP, at the end of PP, and 6 hours after return to supine position (SP). MEASUREMENTS AND MAIN RESULTS: The median duration of postoperative mechanical ventilation was 281 hours (183-528 hours). Prone positioning was carried out on the fourth postoperative day (POD), with a total of 5 patients undergoing PP within 24 hours following surgery. The median duration of PP before return to SP was 12 hours (12-16 hours), with the maximal duration of PP being 22 hours in this cohort. The authors observed an increase in Horowitz index (HI) at the end of PP (p < 0.001) as well as 6 hours after supine positioning. In the subgroup of patients who underwent PP on ECMO (v-a ECLS = 3, v-v ECMO = 3), a significant reduction of ECMO support was achieved from 3.0 (2.2-5.6) liters/min to 2.5 (2.0-4.6) liters/min (p = 0.023). No adverse events occurred during the positioning of the patients. CONCLUSIONS: Prone positioning can be considered for the treatment of ARF after cardiac surgery to improve short-term respiratory conditions and possibly facilitate ECMO weaning.

Design and training effects of a physical reality simulator for minimally invasive mitral valve surgery.

OBJECTIVES: Minimally invasive mitral valve surgery (MIMVS) through an endoscopic right minithoracotomy is a well-established yet complex procedure that has a challenging learning curve. We have developed a simulator for MIMVS and evaluated its short- and long-term training effects. METHODS: Trainees without simulator experience or training in MIMVS were divided into 2 groups (10 students and 10 residents) and participated in a 5-day training course after initial instruction. Each trainee performed a ring annuloplasty. Scores were given by a supervisor who assessed 5 skills. The duration of each procedure was also measured. To evaluate the long-term effect of the training course, trainees performed the same procedure 4 weeks after the last session. RESULTS: Trainees in the resident group were significantly older compared to those in the student group and had a mean surgical experience of 4.4 ± 0.78 years standard error of the mean. All other demographic data were similar. Significant learning curves could be achieved in both groups over the course of 5 days with regard to total skill scores and total duration. However, when we compared the learning curves of both groups, no significant difference could be seen. Long-term performance in both groups was still significantly better compared to that in the first training session. CONCLUSIONS: Training with our simulator provided a significant enhancement of a trainee's performance. This learning effect was achieved in both groups and was still evident 4 weeks later. We strongly recommend our simulator for simulation-based surgical education of cardiac surgeons interested in MIMVS.

Minimally invasive versus conventional extracorporeal circulation circuits in patients undergoing coronary artery bypass surgery: a propensity-matched analysis.

OBJECTIVES: Minimally invasive extracorporeal circulation circuits provide several advantages compared to conventional extracorporeal circulation circuits. We compared the results of a minimally invasive extracorporeal circulation system with those of conventional extracorporeal circulation system, in patients undergoing isolated coronary artery bypass grafting. METHODS: We identified 753 consecutive patients who underwent coronary artery bypass grafting at our centre between October 2014 and September 2016. These patients were divided into two groups: a minimally invasive extracorporeal circulation group (M, n = 229) and a conventional extracorporeal circulation group (C, n = 524). Baseline parameters, details of cardiac surgery as well as postoperative complications and outcomes were compared by means of a propensity-matched analysis of 180 matched pairs. RESULTS: The median EuroSCORE II was 1.3%. Transfusion requirement of packed red blood cells (p = 0.002) was lower in Group M compared to conventional extracorporeal circulation systems. There were no differences in hospital mortality or in rates of adverse events between the matched groups. Total in-hospital mortality of the cohort was 1.7%. CONCLUSION: The use of minimally invasive extracorporeal circulation is associated with a significantly lower use of blood products after isolated coronary revascularisation. There were no differences concerning duration of surgery, complication rates and mortality between the groups. Therefore, the application of minimally invasive extracorporeal circulation systems should be considered as preferred technique in isolated coronary artery bypass grafting procedures.

[Commentary by the German Society for Thoracic and Cardiovascular Surgery on the positions statement by the German Cardiology Society on quality criteria for transcatheter aortic valve implantation (TAVI)]. / Kommentar der Deutschen Gesellschaft für Thorax-, Herz- und Gefäßchirurgie zum Positionspapier der DGK - Qualitätskriterien zur Durchführung der transvaskulären Aortenklappenimplantation (TAVI).

Surgical aortic valve replacement is still considered the first-line treatment for patients suffering from severe aortic valve stenosis. In recent years, transcatheter aortic valve implantation (TAVI) has emerged as an alternative for selected high-risk patients. According to the latest results of the German external quality assurance program, mandatory by law, the initially very high mortality and procedural morbidity have now decreased to approximately 6 and 12%, respectively. Especially in Germany, the number of patients treated by TAVI has increased exponentially. In 2013, a total of 10.602 TAVI procedures were performed. TAVI is claimed to be minimally invasive. This is true concerning the access, but it does not describe the genuine complexity of the procedure, defined by the close neighborhood of the aortic valve to delicate intracardiac structures. Hence, significant numbers of life-threatening complications may occur and have been reported. Owing to the complexity of TAVI, there is a unanimous concordance between cardiologists and cardiac surgeons in the Western world demanding a close heart team approach for patient selection, intervention, handling of complications, and pre- as well as postprocedural care, respectively. The prerequisite is that TAVI should not be performed in centers with no cardiac surgery on site. This is emphasized in all international joint guidelines and expert consensus statements. Today, a small number of patients undergo TAVI procedures in German hospitals without a department of cardiac surgery on site. To be noted, most of these hospitals perform less than 20 cases per year. Recently, the German Cardiac Society (DGK) published a position paper supporting this practice pattern. Contrary to this statement and concerned about the safety of patients treated this way, the German Society for Thoracic and Cardiovascular Surgery (DGTHG) still fully endorses the European (ESC/EACTS) and other actual international guidelines and consensus statements. Only the concomitance of departments for cardiac surgery and cardiology on site can provide optimal TAVI care. This commentary by the DGTHG delineates the data and resources upon which its opinion is based.