The completeness of the left atrial appendage amputation during routine cardiac surgery.

BACKGROUND: Left atrial appendage (LAA) is the origin of most heart thrombi which can lead to stroke or other cerebrovascular event in patients with non-valvular atrial fibrillation (AF). This study aimed to prove safety and low complication rate of surgical LAA amputation using cut and sew technique with control of its effectiveness. METHODS: 303 patients who have undergone selective LAA amputation were enrolled in the study in a period from 10/17 to 08/20. The LAA amputation was performed concomitant to routine cardiac surgery on cardiopulmonary bypass with cardiac arrest with or without previous history of AF. The operative and clinical data were evaluated. Extent of LAA amputation was examined intraoperatively by transoesophageal echocardiography (TEE). Six months in follow up, the patients were controlled regarding clinical status and episodes of strokes. RESULTS: Average age of study population was 69.9 ± 19.2 and 81.9% of patients were male. In only three patients was residual stump after LAA amputation larger than 1 cm with average stump size 0.28 ± 0.34 cm. 3 patients (1%) developed postoperative bleeding. Postoperatively 77 (25.4%) patients developed postoperative AF (POAF), of which 29 (9.6%) still had AF at discharge. On 6 months follow up only 5 patients had NYHA class III and 1 NYHA class IV. Seven patients reported with leg oedema and no patient experienced any cerebrovascular event in early postoperative follow up. CONCLUSION: LAA amputation can be performed safely and completely leaving minimal to no LAA residual stump.

Benefits of Intra-Aortic Balloon Pump Support in Patients with Postcardiotomy Shock Requiring Venoarterial Extracorporeal Membrane Oxygenation.

BACKGROUND: The benefit of the combined use of an intra-aortic balloon pump (IABP) and venoarterial extracorporeal membrane oxygenation (VA-ECMO) for postcardiotomy shock remains unclear. We aimed to analyse the potential benefits and safety of combining these two devices. METHODS: We enrolled 200 patients treated with either VA-ECMO only or in combination with IABP (ECMO-I group) between January 2012 and January 2021. To adjust the patients' backgrounds, we used propensity score matching for additional analyses, resulting in 57 pairs. The primary endpoint was 30-day survival. Secondary endpoints included successful weaning and complication rates. We also analysed hemodynamic parameters in both groups. RESULTS: After propensity score matching, 30-day survival was better in the ECMO-I group (log-rank p = 0.004). The ECMO-I and ECMO-only groups differed regarding the secondary endpoints, including successful weaning (50.9% and 26.3%, respectively; p = 0.012) and the need for continuous renal replacement therapy (28.1% and 50.9%, p = 0.021). Complication rates were not statistically different between the two groups. CONCLUSION: Compared to VA-ECMO alone, the combined use of VA-ECMO and IABP is beneficial regarding 30-day survival in selected patients with postcardiotomy shock; successful ECMO weaning and freedom from renal replacement therapy is more common in patients supported with VA-ECMO plus IABP.

Decellularized Pulmonary Xenograft Matrix PplusN versus Cryopreserved Homograft for RVOT Reconstruction during Ross Procedure in Adults.

BACKGROUND: Decellularized pulmonary homografts are being increasingly adopted for right ventricular outflow tract reconstruction in adult patients undergoing the Ross procedure. Few reports presented Matrix PplusN xenograft (Matrix) in a negative light. The objective of this study was to compare our midterm outcomes of Matrix xenograft versus standard cryopreserved pulmonary homograft (CPHG). METHODS: Eighteen patients received Matrix xenograft between January 2012 and June 2016, whereas 66 patients received CPHG. Using nonparametric statistical tests and survival analysis, we compared midterm echocardiographic and clinical outcomes between the groups. RESULTS: Except for significant age difference (the Matrix group was significantly older with 57 ± 8 years than the CPHG group, 48 ± 9 years, p = 0.02), the groups were similar in all other baseline characteristics. There were no significant differences in cardiopulmonary bypass times (208.3 ± 32.1 vs. 202.8 ± 34.8) or in cross-clamp times (174 ± 33.9 vs. 184.4 ± 31.1) for Matrix and CPHG, respectively. The Matrix group had significantly inferior freedom from reintervention than the CPHG group with 77.8 versus 98.5% (p = 0.02). Freedom from pulmonary valve regurgitation ≥ 2 was not significantly different between the groups with 82.4 versus 90.5% for Matrix versus CPHG, respectively. After median follow-up of 4.9 years, Matrix xenograft developed significantly higher peak pressure gradients compared with CPHG (20.4 ± 15.5 vs. 12.2 ± 9.0 mm Hg; p = 0.04). CONCLUSION: After 5 years of clinical and echocardiographic follow-up, the decellularized Matrix xenograft had inferior freedom from reintervention compared with the standard CPHG. Closer follow-up is necessary to avoid progression of valve failure into right ventricular deterioration.

Central Versus Peripheral Arterial Cannulation for Veno-Arterial Extracorporeal Membrane Oxygenation in Post-Cardiotomy Patients.

Different arterial cannulation strategies are feasible for veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in postcardiotomy shock. We aimed to analyze potential benefits and safety of different arterial cannulation strategies. We identified 158 patients with postcardiotomy cardiogenic shock requiring VA-ECMO between 01/10 and 01/19. Eighty-eight patients were cannulated via axillary or femoral artery (group P), and 70 centrally via the ascending aorta directly or through an 8 mm vascular graft anastomosed to the ascending aorta (group C). Demographics and operative parameters were similar. Change of cannulation site for Harlequin's syndrome or hyperperfusion of an extremity occurred in 13 patients in group P but never in group C (p = 0.001). Surgical revision of cannulation site was also encountered more often in group P than C. The need for left ventricular (LV) unloading was similar between groups, whereas surgical venting was more often implemented in group C (11.4% vs. 2.3, p = 0.023). Stroke rates, renal failure, and peripheral ischemia were similar. Weaning rate from ECMO (52.9% vs. 52.3%, p = NS) was similar. The 30 day mortality was higher in group P (60% vs. 76.1%, p = 0.029). Central cannulation for VA-ECMO provides antegrade flow without Harlequin's syndrome, changes of arterial cannula site, and better 30 day survival. Complication rates regarding need for reexploration and transfusion requirements were similar.

First clinical experience with the novel cold storage SherpaPak™ system for donor heart transportation.

BACKGROUND: The current gold standard for donor heart preservation is a three-bag-technique and storage in a cooler filled with slush ice. This technique can cause freezing injury with protein denaturation. We report our early experience with a single-use disposable device (SherpaPak™, Paragonix Technologies, MA, USA) specifically designed for sterile permanent temperature-controlled transportation of donor hearts. METHODS: In this case control study with 2:1 matching we identified 21 patients after heart transplantation depending on type of organ transport (standard three-bag-technique vs. SherpaPak™). The outcome after donor heart storage in the SherpaPak™ was compared with donor heart transportation with the standard technique. RESULTS: Since July 2018 seven patients (5 males; mean age 50.3±13.2years) underwent heart transplantation with the SherpaPak™ system. Cold ischemic time was longer in the SherpaPak™ group (207.7±23.3 vs. 181.6±21.9, P=0.027). SherpaPak™ kept the organ temperature at 5.1±0.8 °C, with an average outside temperature of 21.4±3.6 °C. Among all 21 transplanted patients four developed fatal early graft failure (28.6% vs. 21.4%, P=0.432). Over the first hours we noticed no difference in hemodynamic parameters, CK-MB levels or vasoactive-inotropic score. During first follow-up we noticed slightly better right heart function in the SherpaPak™ group (TAPSE 17.83±2.71 vs. 14.52±2.61 mm, P=0.020). We identified no positive blood cultures in the SherpaPak™ group within the first 30 days after heart transplantation. CONCLUSIONS: The SherpaPak™ provides a constant temperature during transportation with permanent monitoring, never dropping below 4 °C. Organs transported with this novel device showed a normal perioperative function.

Impact of diabetes mellitus on the contractile properties of the left and right atrial myofilaments.

OBJECTIVES: The incidence of diabetes mellitus in patients with ischaemic cardiomyopathy is increasing. To evaluate the impact of diabetes mellitus on contractility, we examined the calcium-induced force in left and right atrial myofilaments of patients with and without diabetes. METHODS: We included 149 patients (106 without diabetes, 43 with diabetes), scheduled for elective coronary artery bypass grafting from August 2016 to June 2017. The left and right atria were excised and prepared for skinned fibre measurements (pCa-force curve). The unit for the force measurements is Millinewton (mN). Comprehensive demographic data as well as echocardiographic findings of the patients were collected. RESULTS: We observed a significant decrease of left atrial force values in patients with diabetes, averaged over all calcium concentrations (patients with diabetes 0.50 ± 0.19 mN vs 0.68 ± 0.23 mN in patients without diabetes, P = 0.002) as well as in right atrial fibres (patients with diabetes 0.35 ± 0.17 mN vs 0.47 ± 0.21 mN in patients without diabetes, P = 0.005). There was a significant influence of repeated measurements (of the calcium concentrations) on force in left atrial myofilaments (P < 0.001). There was also a significant impact of diabetes on the force values of the different calcium concentrations in left atrial myofilaments (P 0.002). In right atrial myofilaments we also found a significant influence of repeated measurements (of the calcium concentrations) on force (P < 0.001). Additionally the impact of diabetes on the force values was significant (P = 0.005). CONCLUSIONS: We demonstrated that diabetes mellitus has a significantly negative impact on calcium-induced force development in left and right atrial myofilaments.

Rapid deployment valve system shortens operative times for aortic valve replacement through right anterior minithoracotomy.

BACKGROUND: There is growing evidence from the literature that right anterior minithoracotomy aortic valve replacement (RAT-AVR) improves clinical outcome. However, increased cross clamp time is the strongest argument for surgeons not performing RAT-AVR. Rapid deployment aortic valve systems have the potential to decrease cross-clamp time and ease this procedure. We assessed clinical outcome of rapid deployment and conventional valves through RAT. METHODS: Sixty-eight patients (mean age 76 ± 6 years, 32% females) underwent RAT-AVR between 9/2013 and 7/2015. According to the valve type implanted the patients were divided into two groups. In 43 patients (R-group; mean age 74.1 ± 6.6 years) a rapid deployment valve system (Edwards Intuity, Edwards Lifesciences Corp; Irvine, Calif) and in 25 patients (C-group; mean age 74.2 ± 6.6 years) a conventional stented biological aortic valve was implanted. RESULTS: Aortic cross-clamp (42.1 ± 12 min vs. 68.3 ± 20.3 min; p < 0.001) and bypass time (80.4 ± 39.3 min vs. 106.6 ± 23.2 min; p = 0.001) were shorter in the rapid deployment group (R-group). We observed no differences in clinical outcome. Postoperative gradients (R-group: max gradient, 14.3 ± 8 mmHg vs. 15.5 ± 5 mmHg (C-group), mean gradient, 9.2 ± 1.7 mmHg (R-group) vs. 9.1 ± 2.3 mmHg (C-group) revealed no differences. However, larger prostheses were implanted in C-group (25 mm; IQR 23-27 mm vs. 23 mm; IQR 21-25; p = 0.009). CONCLUSIONS: Our data suggest that the rapid deployment aortic valve system reduced cross clamp and bypass time in patients undergoing RAT-AVR with similar hemodynamics as with larger size stented prosthesis. However, larger studies and long-term follow-up are mandatory to confirm our findings.

Myofilament function and body mass index.

Body mass is reported to influence myocardial performance. Recent studies have emphasised the importance of negative inotropic adipocyte-derived factors and their impact on cardiac contractile function. However, the underlying mechanisms remain unclear. We aimed to determine whether body mass impacts cardiac force development on the level of the contractile apparatus. We examined the influence of body mass index (BMI) (3 groups: group I >25, group II 25-30, group III >30) on the myocardial performance of skinned muscle fibres. Right atrial tissue preparations of 70 patients undergoing aortocoronary bypass operation (CABG, 48 patients, group a) and aortic valve replacement (AVR, 22 patients, group b) were obtained. The fibres were exposed to a gradual increase in the calcium concentration, and the force values were recorded. The statistical analysis was performed using Pearson's correlation (P<0.05 significant). A BMI >30 (group III) was associated with less force (mean force 1.58±0.1 mN, P=0.02, max force 2.24±0.17 mN, P=0.02 vs. group II (mean force 1.8±0.3 mN, P=0.04, max force 2.59±0.2 mN, P=0.03) and group I (mean force 1.8±0.1 mN, P=0,03, max force 2.62±0.3 mN, P=0.03). Dividing the groups in the post-surgical procedure, the impact of BMI on force development in group III was more intense in the CABG group compared to the AVR group: 2.0±0.2 mN vs. 2.4±0.1 mN, P=0.04. In accordance with the literature, a BMI >30 is associated with reduced force capacities. Additionally, the underlying cardiac disease may aggravate the impact of weight on cardiac force. Further studies are needed to evaluate the clinical relevance of this experimental observation and the potential consequences for the treatment of cardiac function.

Degree of Carotid Artery Stenosis in Neurologically Asymptomatic Cardiac Surgical Patients Suffering from Perioperative Stroke: Results of an Observational Study.

Background Postoperative stroke in cardiac surgical patients remains a serious adverse outcome. Methods A total of 2,784 consecutively operated cardiac surgical patients without preoperative neurologic impairment were analyzed retrospectively with regard to impact of preoperative carotid stenosis on the incidence of postprocedural new onset of stroke. Therefore, all analyzed patients were assigned to four groups depending on preoperative degree of carotid artery stenosis detected by carotid duplex sonography (group I: < 50%, group II: 50-75%, group III: 76-89%, and group IV: > 90%). Results All pre-, intra-, and postoperative risk factors for neurological disorders were comparable throughout the cohort. Of the 2,784 patients, 65 (2.3%) met the inclusion criteria (preoperatively neurologically asymptomatic status, preoperatively carotid duplex ultrasonography study not older than 6 months, heart surgery with extracorporeal circulation, stroke until 48 hours after operation). Of the 65 patients who met the inclusion criteria, 43 (66.2%) were in group I, 11 (16.9%) in group II, 5 (7.7%) in group III, and 6 (9.2%) in group IV (p = 0.175). The overall incidence of an ipsilateral stroke relating to the carotid stenosis was 38 (1.4%) patients. Of these, 27 (71.1%) patients were in group I, 6 (15.8%) patients in group II, 2 (5.3%) patients in group III, and 3 (7.9%) patients in group IV (p = 0.568). Conclusion This observational study demonstrates that the degree of carotid stenosis in neurologically asymptomatic cardiac surgical patients is not able to predict the probability of perioperative stroke. Until further results from prospective randomized trials with neurologically asymptomatic cardiac surgical patients are presented, a cautious attitude for concomitant carotid endarterectomy is still justified.

Different duration strategies of perioperative antibiotic prophylaxis in adult patients undergoing cardiac surgery: an observational study.

BACKGROUND: All international guidelines recommend perioperative antibiotic prophylaxis (PAB) should be routinely administered to patients undergoing cardiac surgery. However, the duration of PAB is heterogeneous and controversial. METHODS: Between 01.01.2011 and 31.12.2011, 1096 consecutive cardiac surgery patients were assigned to one of two groups receiving PAB with a second-generation cephalosporin for either 56 h (group I) or 32 h (group II). Patients' characteristics, intraoperative data, and the in-hospital follow-up were analysed. Primary endpoint was the incidence of surgical site infection (deep and superficial sternal wound-, and vein harvesting site infection; DSWI/SSWI/VHSI). Secondary endpoints were the incidence of respiratory-, and urinary tract infection, as well as the mortality rate. RESULTS: 615/1096 patients (56,1%) were enrolled (group I: n = 283 versus group II: n = 332). There were no significant differences with regard to patient characteristics, comorbidities, and procedure-related variables. No statistically significant differences were demonstrated concerning primary and secondary endpoints. The incidence of DSWI/SSWI/VHSI were 4/283 (1,4%), 5/283 (1,7%), and 1/283 (0,3%) in group I versus 6/332 (1,8%), 9/332 (2,7%), and 3/332 (0,9%) in group II (p = 0,76/0,59/0,63). In univariate analyses female gender, age, peripheral arterial obstructive disease, operating-time, ICU-duration, transfusion, and respiratory insufficiency were determinants for nosocomial infections (all ≤ 0,05). Subgroup analyses of these high-risk patients did not show any differences between the two regimes (all ≥ 0,05). CONCLUSIONS: Reducing the duration of PAB from 56 h to 32 h in adult cardiac surgery patients was not associated with an increase of nosocomial infection rate, but contributes to reduce antibiotic resistance and health care costs.

Cardiac surgery antibiotic prophylaxis and calculated empiric antibiotic therapy.

BACKGROUND: Ongoing debate exists concerning the optimal choice and duration of antibiotic prophylaxis as well as the reasonable calculated empiric antibiotic therapy for hospital-acquired infections in critically ill cardiac surgery patients. METHODS: A nationwide questionnaire was distributed to all German heart surgery centers concerning antibiotic prophylaxis and the calculated empiric antibiotic therapy. RESULTS: The response to the questionnaire was 87.3%. All clinics that responded use antibiotic prophylaxis, 79% perform it not longer than 24 h (single-shot: 23%; 2 doses: 29%; 3 doses: 27%; 4 doses: 13%; and >5 doses: 8%). Cephalosporin was used in 89% of clinics (46% second-generation, 43% first-generation cephalosporin). If sepsis is suspected, the following diagnostics are performed routinely: wound inspection 100%; white blood cell count 100%; radiography 99%; C-reactive protein 97%; microbiological testing of urine 91%, blood 81%, and bronchial secretion 81%; procalcitonin 74%; and echocardiography 75%. The calculated empiric antibiotic therapy (depending on the suspected focus) consists of a multidrug combination with broad-spectrum agents. CONCLUSION: This survey shows that existing national guidelines and recommendations concerning perioperative antibiotic prophylaxis and calculated empiric antibiotic therapy are well applied in almost all German heart centers.

The predictive value of multiple electrode platelet aggregometry (multiplate) in adult cardiac surgery.

BACKGROUND: The purpose of this retrospective observational study is to analyze the value of multiple electrode platelet aggregometry (Multiplate analyzer, Verum Diagnostica, Munich) as a point-of-care (POC) device in adult cardiac surgical patients. METHODS: Two hundred and twenty-three cardiac surgical patients were analyzed preoperatively and postoperatively with multiple electrode platelet aggregometry by stimulation ADPtest, ASPItest, and TRAPtest. End points were postoperative bleeding, need for reexploration, and perioperative transfusions requirements. Furthermore, a literature survey using the key phrases "platelet function" and "cardiac surgery" was performed. RESULTS: When comparing patients with normal Multiplate test results concerning end points, patients with pathological ADPtest (n = 140) needed significant more platelet concentrates (PCs) (p = 0.009), patients with pathological ASPItest (n = 175) did not show any significant differences, and patients with pathological TRAPtest (n = 139) needed more red blood cells (p = 0.008) and PCs (p = 0.02). The literature survey showed 208 hits, spanning the publication years 2002 to 2012 resulted in 123 hits. CONCLUSIONS: The ADPtest and the TRAPtest significantly predict the requirement of perioperative blood transfusion. Therefore, multiple electrode platelet aggregometry is beneficial for POC testing in cardiac surgical patients. Prospective, randomized, and controlled clinical studies are rare.

Policies of withholding and withdrawal of life-sustaining treatment in critically ill patients on cardiac intensive care units in Germany: a national survey.

OBJECTIVE: To determine the decision-making process of withholding and/or withdrawal (WH/WD) of life-sustaining treatment in cardiac intensive care units (ICUs) in Germany. METHODS: A questionnaire regarding 16 medical and 6 ethical questions of WH/WD of life-sustaining treatment was distributed to the clinical director, senior ICU physician and head nurses of all German heart surgery centres (n = 237 questionnaires). Furthermore, we present a literature survey using the key words 'End-of-life care AND withholding/withdrawal of life support therapy AND intensive care unit'. RESULTS: We received replies from 86 of 237 (36.3%) contacted persons. Concerning medical reasons, cranial computed tomography (CCT) with poor prognosis (91.9%), multi-organ failure (70.9%) and failure of assist device therapy (69.8%) were the three most frequently cited medical reasons for WH/WD life-sustaining treatment. Overall, 32.6% of persons answered that ethical aspects influence their decision-making processes. Poor expected quality of life (48.8%), the patient's willingness to limit medical care (40.7%) and the families' choice (27.9%) were the top three reported ethical reasons. There was a significant difference regarding the perception of the three involved professional groups concerning the decision-making parameters: multi-organ failure (P = 0.018), failure of assist device therapy (P = 0.001), cardiac index (P = 0.009), poor expected quality of life (P = 0.009), the patient's willingness to limit medical care (P = 0.002), intraoperative course (P = 0.054), opinion of family members (P = 0.032) and whether decision-making process are done collaboratively (clinical director, 45.7%; ICU physician, 52%; and head of nursing staff, 26.9%). Palliation medication in patients after WH/WD of life-support consisted of morphine (92%) and benzodiazepines (88%). CONCLUSIONS: This survey is a step towards creating standards of end-of-life care in cardiac ICUs, which may contribute to build consensus and avoid conflicts among caregivers, patients and families at each step of the decision-making process.