Continuous Long-Term Assessment of Heart Rate Variability in Adults with Cyanotic Congenital Heart Disease after Surgical Repair.

Background: Heart rate variability (HRV) is an established, non-invasive parameter for the assessment of cardiac autonomic nervous activity and the health status in general cardiology. However, there are few studies on HRV in adults with congenital heart defects (CHDs). The aim of the present study was to evaluate the use of long-term continuous HRV measurement for the assessment of global health status in adults with cyanotic CHD. Methods: This prospective study included 45 adults (40% female, mean age = 35.2 ± 9.2 [range: 19-58] years) after cardiac surgical repair. HRV parameters were calculated from continuous 24 h measurements using a Bittium Faros 180 sensor (Bittium Corp., Oulu, Finland). Results: Postoperative patients with transposition of the great arteries (TGA) (n = 18) achieved significantly higher values of standard deviation of NN intervals (SDNN) (175.4 ± 59.9 ms vs. 133.5 ± 40.6 ms; p = 0.013) compared with patients with other conotruncal anomalies (n = 22). Comparing patients with TGA after a Senning-Brom or Mustard operation (n = 13) with all other heart surgery patients (n = 32), significantly higher HRV parameters were found after atrial switch (root mean square of successive RR interval differences: 53.6 ± 20.7 ms vs. 38.4 ± 18.3 ms; p = 0.019; SDNN: 183.5 ± 58.4 ms vs. 136.3 ± 45.3 ms; p = 0.006). A higher SDNN was also measured after Senning-Brom or Mustard operations than after a Rastelli operations (n = 2) (SDNN: 183.5 ± 58.4 ms vs. 84.5 ± 5.2 ms; p = 0.037). When comparing atrial switch operations (n = 3) with Rastelli operations, the SDNN value was significantly shorter in the Rastelli group (p = 0.004). Conclusions: Our results suggest that continuous HRV monitoring may serve as a marker of cardiac autonomic dysfunction in adults with cyanotic CHD after surgical repair. Impaired cardiac autonomic nervous activity may be associated with an increased risk of adverse reactions in patients with repaired CHD. Therefore, a longitudinal assessment of HRV patterns and trends may provide a deeper insight into dynamic changes in their autonomic regulation and disease progression, lifestyle changes, or treatments. As each person has individual variability in heart rate, HRV may be useful in assessing intra-individual disease progression and may help to improve personalized medicine. Further studies are needed to better understand the underlying mechanisms and to explore the full potential of HRV analysis to optimize medical care for ACHDs.

PATHFINDER-CHD: prospective registry on adults with congenital heart disease, abnormal ventricular function, and/or heart failure as a foundation for establishing rehabilitative, prehabilitative, preventive, and health-promoting measures: rationale, aims, design and methods.

BACKGROUND: Adults with congenital heart defects (ACHD) globally constitute a notably medically underserved patient population. Despite therapeutic advancements, these individuals often confront substantial physical and psychosocial residua or sequelae, requiring specialized, integrative cardiological care throughout their lifespan. Heart failure (HF) is a critical challenge in this population, markedly impacting morbidity and mortality. AIMS: The primary aim of this study is to establish a comprehensive, prospective registry to enhance understanding and management of HF in ACHD. Named PATHFINDER-CHD, this registry aims to establish foundational data for treatment strategies as well as the development of rehabilitative, prehabilitative, preventive, and health-promoting interventions, ultimately aiming to mitigate the elevated morbidity and mortality rates associated with congenital heart defects (CHD). METHODS: This multicenter survey will be conducted across various German university facilities with expertise in ACHD. Data collection will encompass real-world treatment scenarios and clinical trajectories in ACHD with manifest HF or at risk for its development, including those undergoing medical or interventional cardiac therapies, cardiac surgery, inclusive of pacemaker or ICD implantation, resynchronization therapy, assist devices, and those on solid organ transplantation. DESIGN: The study adopts an observational, exploratory design, prospectively gathering data from participating centers, with a focus on patient management and outcomes. The study is non-confirmatory, aiming to accumulate a broad spectrum of data to inform future hypotheses and studies. PROCESSES: Regular follow-ups will be conducted, systematically collecting data during routine clinical visits or hospital admissions, encompassing alterations in therapy or CHD-related complications, with visit schedules tailored to individual clinical needs. ASSESSMENTS: Baseline assessments and regular follow-ups will entail comprehensive assessments of medical history, ongoing treatments, and outcomes, with a focus on HF symptoms, cardiac function, and overall health status. DISCUSSION OF THE DESIGN: The design of the PATHFINDER-CHD Registry is tailored to capture a wide range of data, prioritizing real-world HF management in ACHD. Its prospective nature facilitates longitudinal data acquisition, pivotal for comprehending for disease progression and treatment impacts. CONCLUSION: The PATHFINDER-CHD Registry is poised to offer valuable insights into HF management in ACHD, bridging current knowledge gaps, enhancing patient care, and shaping future research endeavors in this domain.

Paediatric aortic valve replacement using decellularized allografts: a multicentre update following 143 implantations and five-year mean follow-up.

OBJECTIVES: Decellularized aortic homografts (DAH) were introduced in 2008 as a further option for paediatric aortic valve replacement (AVR). METHODS: Prospective, multicentre follow-up of all paediatric patients receiving DAH for AVR in 8 European centres. RESULTS: A total of 143 DAH were implanted between February 2008 and February 2023 in 137 children (106 male, 74%) with a median age of 10.8 years (interquartile range 6.6-14.6). Eighty-four (59%) had undergone previous cardiac operations and 24 (17%) had undergone previous AVR. The median implanted DAH diameter was 21 mm (interquartile range 19-23). The median operation duration was 348 min (227-439) with a median cardiopulmonary bypass time of 212 min (171-257) and a median cross-clamp time of 135 min (113-164). After a median follow-up of 5.3 years (3.3-7.2, max. 15.2 years), the primary efficacy end-points peak gradient (median 14 mmHg, 9-28) and regurgitation (median 0.5, interquartile range 0-1, grade 0-3) showed good results but an increase over time. Freedom from death/explantation/endocarditis/bleeding/thromboembolism at 5 years were 97.8 ± 1.2/88.7 ± 3.3/99.1 ± 0.9/100 and 99.2 ± 0.8%, respectively. Freedom from death/explantation/endocarditis/bleeding/thromboembolism at 10 years were 96.3 ± 1.9/67.1 ± 8.0/93.6 ± 3.9/98.6 ± 1.4 and 86.9 ± 11.6%, respectively. In total, 21 DAH were explanted. Seven were replaced by a mechanical AVR, 1 Ross operation was performed and a re-do DAH was implanted in 13 patients with no redo mortality. The calculated expected adverse events were lower for DAH compared to cryopreserved homograft patients (mean age 8.4 years), and in the same range as for Ross patients (9.2 years) and mechanical AVR (13.0 years). CONCLUSIONS: This large-scale prospective analysis demonstrates excellent mid-term survival using DAH with adverse event rates comparable to paediatric Ross procedures.

Changes of the nociceptive flexion reflex threshold in patients undergoing cardiac surgery-a prospective clinical pilot study.

Opioid dosage for general anaesthesia and sedation relies on surrogate parameters such as heartrate and blood pressure. This implies the risk of both under- and overdosing. A promising tool to provide target-oriented opioid dosing is measuring the nociceptive flexion reflex threshold (NFRT). The aim of this study was to investigate the individual trajectories and to determine this methods' clinical practicability in the perioperative setting of cardiac surgery. NFRT was measured preoperatively (twice as baseline), immediately after surgery and later in the general ward (primary outcomes). No intraoperative measurements were performed since neuromuscular blockade hinders NFRT assessment. Administered analgesics and pain scores were also recorded (secondary outcomes). Data were collected from August 2019 to March 2020. 264 patients scheduled for cardiac surgery were screened for eligibility. 55 patients were included, 30 rendered datasets for analysis. Thresholds after conclusion of surgery [TICU: median (IQR), 31.1 mA (21.5-50.0 mA)] were significantly higher than preoperatively [Tpre: 9.2 mA (5.4-13.4 mA); P < 0.001]. In 11 patients (36.7%), no immediate postoperative reflex response was elicited. Later, all reflexes returned, but thresholds remained significantly higher than preoperatively [Tpost: 11.9 mA (9.2-16.6 mA); P = 0.043]. NFRT values after surgery were higher compared to baseline measurements. Subsequently they decreased but did not reach their baseline levels. There was no corresponding dose-dependency, suggesting multimodal effects on the nociceptive system. Unless measurements are not prevented by technical issues NFRT-assessment appears to be a future tool to target analgesics in patients not able to self-report pain. Trial registration Study registration: DRKS00021617. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00021617 (registered retrospectively).

[Disorientation and delirium assessment : A secondary analysis of a prospective, observational study]. / Bedeutung der Desorientierung bei der Delireinschätzung : Sekundäranalyse einer prospektiven, observationellen Studie.

Disorientation may present as a warning sign of developing delirium. The most commonly used delirium assessment tool in Germany, the Confusion Assessment Method for Intensive Care Unit (CAM-ICU), does not rate "disorientation", since intubated patients cannot communicate verbally. However, the majority of German ICU patients are not orally intubated, so they could be examined for their orientation. This study was carried out to investigate whether the delirium feature "disorientation" in extubated patients yields diverging findings in comparison to the CAM-ICU and whether the sensitivity of the CAM-ICU may be improved when combined with the feature "disorientation" (CAM-IMC). A total of 86 paired assessments were completed in 50 extubated patients. Delirium was found in 19.8% (N = 17). The CAM-ICU had a sensitivity of 71% (95% confidence interval [CI] 44-90%) and a specificity of 100% (95-100%). Disorientation, if taken as the only delirium feature, had a sensitivity of 77% (50-93%) and a specificity of 93% (89-100%). The CAM-IMC reached a sensitivity of 88% (64-99%) and a specificity of 100% (95-100%). The receiver operating characteristics (ROC) analyses found an area under the curve (AUC) of 0.941 (95%CI 0.851-1.000) for the CAM-IMC, which was the highest compared to the other delirium tests (CAM-ICU, AUC 0.853 [0.720-0.986]; disorientation, AUC 0.868 [0.745-0.991]). This research emphasizes the importance of the feature "disorientation" for delirium assessments in patients able to verbally communicate and explains some controversial delirium ratings in daily practice. The CAM-IMC appears to be an attractive tool for delirium assessment in nonintubated patients and deserves further research.

The value of perioperative biomarker release for the assessment of myocardial injury or infarction in cardiac surgery.

OBJECTIVES: Cardiac biomarkers are indicators of irreversible cell damage. Current myocardial infarction (MI) definitions require concomitant clinical characteristics. For perioperative MI, a correlation of biomarker elevations and mortality has been suggested. Definitions emerged relying on cardiac biomarker release only. This approach is questionable as several clinical and experimental scenarios exist where relevant biomarker release can occur apart from MI. METHODS: We reviewed the clinical and basic science literature and revealed important aspects regarding the use and interpretation of cardiac biomarker release with special focus on their interpretation in the perioperative setting. RESULTS: Ischaemic biomarkers may be released without cell death in multiple conditions, such as after endurance runs in athletes, temporary inotropic stimulation in animal models and flow variations in in vitro cell models. In addition, access through atrial tissue during cannulation or concomitant valve procedures adds sources of enzyme release that may not be related to ventricular ischaemia (i.e. MI). Such non-cell death-related mechanisms may explain the lack of poor correlations of enzyme release and long-term outcomes in recent trials. In addition, the 3 main biomarkers, troponin T, I and creatine kinase myocardial band, differ in their release kinetics, which may differentially trigger MI events in trial patients. CONCLUSIONS: The identification of irreversible myocardial injury in cardiac surgery based only on biomarker release is unreliable. Cell death- and non-cell death-related mechanisms create a mix in the perioperative setting that requires additional markers for proper identification of MI. In addition, the 3 most common ischaemic biomarkers display different release kinetics adding to the confusion. We review the topic.

Impact of pre-existing comorbidities on outcomes of patients undergoing surgical aortic valve replacement - rationale and design of the international IMPACT registry.

BACKGROUND: Degenerative aortic valve disease accounts for 10-20% of all cardiac surgical procedures. The impact of pre-existing comorbidities on the outcome of patients undergoing surgical aortic valve replacement (SAVR) needs further research. METHODS: The IMPACT registry is a non-interventional, prospective, open-label, multicenter, international registry with a follow-up of 5 years to assess the impact of pre-existing comorbidities of patients undergoing SAVR with the INSPIRIS RESILIA aortic valve on outcomes. IMPACT will be conducted across 25 sites in Austria, Germany, The Netherlands and Switzerland and intends to enroll approximately 500 patients. Patients will be included if they are at least 18 years of age and are scheduled to undergo SAVR with the INSPIRIS RESILIA Aortic Valve with or without concomitant ascending aortic root replacement and/or coronary bypass surgery. The primary objective is to determine all-cause mortality at 1, 3, and 5 years post SAVR. Secondary objectives include cardiac-related and valve-related mortality and structural valve deterioration including hemodynamics and durability, valve performance and further clinical outcomes in the overall study population and in specific patient subgroups characterized by the presence of chronic kidney disease, hypertension, metabolic syndrome and/or chronic inflammation. DISCUSSION: IMPACT is a prospective, multicenter European registry, which will provide much-needed data on the impact of pre-existing comorbidities on patient outcomes and prosthetic valve performance, and in particular the performance of the INSPIRIS RESILIA, in a real-world setting. The findings of this study may help to support and expand appropriate patient selection for treatment with bioprostheses. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04053088 .

Preoperative Cognitive Impairment and Postoperative Delirium Predict Decline in Activities of Daily Living after Cardiac Surgery-A Prospective, Observational Cohort Study.

Cardiac surgery and subsequent treatment in the intensive care unit (ICU) has been shown to be associated with functional decline, especially in elderly patients. Due to the different assessment tools and assessment periods, it remains yet unclear what parameters determine unfavorable outcomes. This study sought to identify risk factors during the entire perioperative period and focused on the decline in activity of daily living (ADL) half a year after cardiac surgery. Follow-ups of 125 patients were available. It was found that in the majority of patients (60%), the mean ADL declined by 4.9 points (95% CI, -6.4 to -3.5; p < 0.000). In the "No decline" -group, the ADL rose by 3.3 points (2.0 to 4.6; p < 0.001). A multiple regression analysis revealed that preoperative cognitive impairment (MMSE ≤ 26; Exp(B) 2.862 (95%CI, 1.192-6.872); p = 0.019) and duration of postoperative delirium ≥ 2 days (Exp(B) 3.534 (1.094-11.411); p = 0.035) was independently associated with ADL decline half a year after the operation and ICU. Of note, preoperative ADL per se was neither associated with baseline cognitive function nor a risk factor for functional decline. We conclude that the preoperative assessment of cognitive function, rather than functional assessments, should be part of risk stratification when planning complex cardiosurgical procedures.

CpG postconditioning after reperfused myocardial infarction is associated with modulated inflammation, less apoptosis, and better left ventricular function.

Postconditioning attenuates inflammation and fibrosis in myocardial infarction (MI). The aim of this study was to investigate whether postconditioning with the cytosine-phosphate-guanine (CpG)-containing Toll-like receptor-9 (TLR9) ligand 1668-thioate (CpG) can modulate inflammation and remodeling in reperfused murine MI. Thirty minutes of left descending coronary artery (LAD) occlusion was conducted in 12-wk-old C57BL/6 mice. Mice were treated with CpG intraperitoneally 5 min before reperfusion. The control group received PBS; the sham group did not undergo ischemia. M-mode echocardiography (3, 7, and 28 days) and Millar left ventricular (LV) catheterization were performed (7 and 28 days) before the hearts were excised and harvested for immunohistochemical (6 h, 24 h, 3 days, 7 days, and 28 days), gene expression (6 h, 24 h, and 3 days; Taqman RT-qPCR), protein, and FACS analysis (24 h and 3 days). Mice treated with CpG showed significantly better LV function after 7 and 28 days of reperfusion. Protein and mRNA expressions of proinflammatory and anti-inflammatory cytokines were significantly induced after CpG treatment. Histology revealed fewer macrophages in CpG mice after 24 h, confirmed by FACS analysis with a decrease in both classically M1- and alternative M2a-monocytes. CpG treatment reduced apoptosis and cardiomyocyte loss and was associated with induction of adaptive mechanisms, e.g., of heme-oxigenase-1 and ß-/α-myosin heavy chain (MHC) ratio. Profibrotic markers collagen type Iα (Col-Ια) and Col-III induction was abrogated in CpG mice, accompanied by fewer myofibroblasts. This led to the formation of a smaller scar. Differential matrix metalloproteinase (MMP)/tissue inhibitor of metalloproteinase (TIMP) expression contributed to attenuated remodeling in CpG, resulting in preserved cardiac function in a Toll-like receptor 1- and TLR9-dependent manner. Our study suggests a cardioprotective mechanism of CpG postconditioning, involving Toll-like receptor-driven modulation of inflammation. This is followed by attenuated remodeling and preserved LV function.NEW & NOTEWORTHY Cytosine-phosphate-guanine (CpG) postconditioning seems to mediate inflammation via Toll-like receptor-1 and Toll-like receptor-9 signaling. Enhanced cytokine and chemokine expressions are partly attenuated by IL-10 and matrix metalloproteinase-8 (MMP8) induction, being associated with lower macrophage infiltration and M1-monocyte differentiation. Furthermore, switch from α- to ß-MHC and balanced MMP/TIMP expression led to lesser cardiomyocyte apoptosis, smaller scar size, and preserved cardiac function. Data of pharmacological postconditioning have been widely disappointing to date. Our study suggests a new pathway promoting myocardial postconditioning via Toll-like receptor activation.

Timely extracorporeal membrane oxygenation assist reduces mortality after bypass surgery in patients with acute myocardial infarction.

BACKGROUND: Patients with acute myocardial infarction (AMI) are at high risk when undergoing emergency coronary artery bypass graft (CABG)-surgery. Their outcome remains poor despite increased use of extracorporeal membrane oxygenation (ECMO). We investigated the impact of timing for perioperative ECMO-support in these patients. METHODS: In this retrospective double-center study, we evaluated 201 patients with AMI undergoing CABG, dividing them into the following groups: No-ECMO (n = 101), preoperative ECMO (pre-ECMO, n = 6), intraoperative ECMO (ECC-ECMO, n = 67), and postoperative ECMO (post-ECMO, n = 27). We evaluated the impact of ECMO timing on postoperative mortality, organ function, and length of stay, comparing these to predicted outcome using different risk-scores. RESULTS: Post-ECMO patients showed lowest 30-day-survival (40.7%), while earlier ECMO-start was associated with better outcome (50.7% in extracorporeal circulation [ECC]-ECMO and 66.7% in pre-ECMO patients). On admission, only pre-ECMO and ECC-ECMO patients showed higher surgery- and intensive-care-unit (ICU)-related risk-scores. In pre- and ECC-ECMO patients, the first significant increase in lactate-levels (>4 mmol/L) was observed preoperatively, while this occurred 1 hour postoperatively in post-ECMO patients. Bilirubin was increased in all patients, decreasing after 3 and 12 days in pre- and ECC-ECMO patients, respectively, but only after 18 days in post-ECMO patients. Multiple ICU risk-scores did not discriminate survival-probability correctly. Only the ECMO-related survival after veno-arterial-ECMO-score correctly predicted the significantly lower survival in post-ECMO patients. CONCLUSION: Our study shows that timely ECMO-support is associated with earlier bilirubin-downtrend and higher survival in patients with AMI after CABG. Lactate-increase greater than 4 mmol/L seems to be a helpful threshold to trigger the timely onset of ECMO-therapy, providing better survival.

CB2-deficiency is associated with a stronger hypertrophy and remodeling of the right ventricle in a murine model of left pulmonary artery occlusion.

AIMS: Pulmonary hypertension (PH) leads to right ventricular (RV) adaptation and remodeling and has deleterious long-term effects on RV function. The endocannabinoid receptor CB2 has been associated with protective effects in adaptation and remodeling of the left ventricle after ischemia. Therefore, we investigated the role of CB2 receptor in RV adaptation after occlusion of the left pulmonary artery (LPA) in a murine model. MAIN METHODS: C57/Bl6 (WT)- and CB2 receptor-deficient (Cnr2-/-)-mice underwent paramedian sternotomy and LPA was occluded using a metal clip. Right heart hemodynamic study (Millar®) preceded organ harvesting for immunohistochemistry and mRNA analysis 7 and 21 days (d) post-occlusion. KEY FINDINGS: LPA occlusion led to higher RV systolic pressure in Cnr2-/--hearts, while hemodynamics were comparable with WT-hearts after 21d. Cnr2-/--hearts showed higher macrophage infiltration and lower interleukin-10 expression after 7 d, but otherwise a comparable inflammatory mediator expression profile. Cardiomyocyte-hypertrophy was stronger in Cnr2-/--mice, presenting with higher tenascin-C expression than WT-hearts. Planimetry revealed higher collagen area in Cnr2-/--hearts and small areas of cardiomyocyte-loss. Surrounding cardiomyocytes were cleaved caspase-3- and TUNEL positive in Cnr2-/--hearts. This was associated by maladaptation of myosin heavy-chain isoforms and lower reactive oxygen scavenger enzymes induction in Cnr2-/--hearts. We found comparable morphological changes in both lungs between the two genotypes. SIGNIFICANCE: LPA occlusion led to increased systolic pressure and adaptation of RV in CB2-deficient mice. CB2 receptor seems to modulate RV adaptation through expression of contractile elements, reactive oxygen scavenger enzymes, and inflammatory response in order to prevent cardiomyocyte apoptosis.

The provision of pediatric cardiac anesthesia services in Germany: current status of structural and personnel organization.

BACKGROUND: Anesthesia for pediatric cardiac surgery requires a high level of expert knowledge. There are currently no recommendations and standards for anesthetic management for congenital cardiac surgery in Germany. AIM: The aim of the present study was to assess the current status of structural and personnel anesthetic standards at pediatric cardiac surgery centers in Germany. METHODS: All cardiac surgical centers in Germany were reviewed for an active program for congenital heart surgery. Centers with an active program were invited to respond to an online survey. The questionnaire containing 55 items in 16 categories assessed current practice in pediatric cardiac anesthesia. RESULTS: An active program for pediatric cardiac surgery was identified at 27 centers. The response rate to the survey was 96.3%. A specialized group of anesthesiologists for pediatric cardiac anesthesia was reported from 26 centers (92.3%). The mean size of this group was 4.8 anesthesiologists per center. However, the annual case load of centers and relative annual case load per specialized anesthesiologist varied considerably between 12.5 and 250. Nonanesthesiologists performed sedation and general anesthesia for diagnostic and therapeutic interventions outside the operating theater in children with congenital heart diseases in 24 centers (77%). Although special equipment, for example, pediatric TEE, near-infrared spectroscopy, and devices for mechanical auto transfusion were available in most centers, their routine use was not always part of standard operating procedures. The proposal for mean adequate training in pediatric cardiac anesthesia as estimated by the participating centers was 10.8 months. CONCLUSION: The present study represents the current structural situation for anesthesia at German pediatric cardiac surgery centers.

Comparison of stroke volumes assessed by three-dimensional echocardiography and transpulmonary thermodilution in a pediatric animal model.

To compare stroke volumes (SV) in small hearts assessed by real-time three-dimensional echocardiography (3DE) with SV measured by transpulmonary thermodilution (TPTD) and continuous pulse contour analysis (PC) under various hemodynamic conditions. In thirteen anesthetized piglets (range 3.6-7.1 kg) SV were measured by 3DE, TPTD and PC at baseline and during phenylephrine and esmolol administration. 3DE and TPTD measurements were done successively while SV calculated by PC was documented at the time of 3DE. 3DE and TPTD showed a good correlation (r2 = 0.74) and a bias of -1.3 ml (limits of agreement -4.1 to 1.5 ml). While TPTD measured higher SV than 3DE, both methods tracked SV changes with a concordance rate of 91 %. PC and 3DE showed a lower correlation coefficient of r2 = 0.57 and a bias of -2.1 ml (limits of agreement -5.9 to 1.8 ml). Inter- and intra-observer variability of SV measured by 3DE was good with a mean bias <5 %. SV3DE showed a small variance and tracked acute small changes in SV in acceptable concordance with TPTD. PC measured SV with a higher variance and mean difference compared to 3DE. In an experimental setting 3DE has the possibility to offer non-invasive assessments of ventricular volumes volume changes. To determine whether 3DE could be used for SV assessment in a clinical routine our results need confirmation in a clinical setting.

A role for 12/15-lipoxygenase-derived proresolving mediators in postoperative ileus: protectin DX-regulated neutrophil extravasation.

Resolution of inflammation is an active counter-regulatory mechanism involving polyunsaturated fatty acid-derived proresolving lipid mediators. Postoperative intestinal motility disturbances, clinically known as postoperative ileus, occur frequently after abdominal surgery and are mediated by a complex inflammation of the intestinal muscularis externa. Herein, we tested the hypothesis that proresolving lipid mediators are involved in the resolution of postoperative ileus. In a standardized experimental model of postoperative ileus, we detected strong expression of 12/15-lipoxygenase within the postoperative muscularis externa of C57BL/6 mice, predominately located within CX3CR1(+)/Ly6C(+) infiltrating monocytes rather than Ly6G(+) neutrophils. Mass spectrometry analyses demonstrated that a 12/15-lipoxygenase increase was accompanied by production of docosahexaenoic acid-derived lipid mediators, particularly protectin DX and resolvin D2, and their common precursor 17-hydroxy docosahexaenoic acid. Perioperative administration of protectin DX, but not resolvin D2 diminished blood-derived leukocyte infiltration into the surgically manipulated muscularis externa and improved the gastrointestinal motility. Flow cytometry analyses showed impaired Ly6G(+)/Ly6C(+) neutrophil extravasation after protectin DX treatment, whereas Ly6G(-)/Ly6C(+) monocyte numbers were not affected. 12/15-lipoxygenase-deficient mice, lacking endogenous protectin DX synthesis, demonstrated increased postoperative leukocyte levels. Preoperative intravenous administration of a docosahexaenoic acid-rich lipid emulsion reduced postoperative leukocyte infiltration in wild-type mice but failed in 12/15-lipoxygenase-deficient mice mice. Protectin DX application reduced leukocyte influx and rescued 12/15-lipoxygenase-deficient mice mice from postoperative ileus. In conclusion, our results show that 12/15-lipoxygenase mediates postoperative ileus resolution via production of proresolving docosahexaenoic acid-derived protectin DX. Perioperative, parenteral protectin DX or docosahexaenoic acid supplementation, as well as modulation of the 12/15-lipoxygenase pathway, may be instrumental in prevention of postoperative ileus.

Activation of Endocannabinoid System Is Associated with Persistent Inflammation in Human Aortic Aneurysm.

Human aortic aneurysms have been associated with inflammation and vascular remodeling. Since the endocannabinoid system modulates inflammation and tissue remodeling, we investigated its components in human aortic aneurysms. We obtained anterior aortic wall samples from patients undergoing elective surgery for aortic aneurysm or coronary artery disease as controls. Histological and molecular analysis (RT-qPCR) was performed, and endocannabinoid concentration was determined using LC-MRM. Patient characteristics were comparable between the groups except for a higher incidence of arterial hypertension and diabetes in the control group. mRNA level of cannabinoid receptors was significantly higher in aneurysms than in controls. Concentration of the endocannabinoid 2-arachidonoylglycerol was significantly higher, while the second endocannabinoid anandamide and its metabolite arachidonic acid and palmitoylethanolamide were significantly lower in aneurysms. Histology revealed persistent infiltration of newly recruited leukocytes and significantly higher mononuclear cell density in adventitia of the aneurysms. Proinflammatory environment in aneurysms was shown by significant upregulation of M-CSF and PPARγ but associated with downregulation of chemokines. We found comparable collagen-stained area between the groups, significantly decreased mRNA level of CTGF, osteopontin-1, and MMP-2, and increased TIMP-4 expression in aneurysms. Our data provides evidence for endocannabinoid system activation in human aortic aneurysms, associated with persistent low-level inflammation and vascular remodeling.

CB2 receptor-mediated effects of pro-inflammatory macrophages influence survival of cardiomyocytes.

AIMS: The endocannabinoid system and cannabinoid receptor 2 (CB2 receptor) have been associated with modulation of inflammatory response and myocardial adaptation after ischemic injury. In order to elucidate CB2 receptor-related effects during cellular interactions, we investigated cardiomyocyte survival and macrophage function in vitro. MAIN METHODS: Murine embryonic (eCM) and adult (CM) cardiomyocytes, murine macrophages (MO), and their subtypes M1 (M1-MO) and M2 (M2-MO) were derived from wildtype- (WT) and CB2 receptor-deficient (Cnr2(-/-)) mice. Cells were cultured separately or in co-culture under normoxia or hypoxia (2% O2) and pro-inflammatory stimulation using interferon (IFN)γ. Besides immunohistochemistry, we also measured mRNA expression (Taqman®) and performed FACS-analysis of cardiomyocytes. Macrophage migration was assessed using Boyden chamber assay. KEY FINDINGS: We found a significant induction of CB2 receptor mRNA and protein in murine eCM as well as M1- and M2-MO in vitro following cultivation under hypoxia or stimulation with IFNγ. A significantly higher amount of apoptotic Cnr2(-/-)-CMs was found after incubation under hypoxia when compared to WT-CMs. We observed a significantly stronger migration potential in Cnr2(-/-)-M1-MOs towards the supernatant of apoptotic CM, than in corresponding WT-cells. Co-culture revealed a significantly higher loss of eCMs and induction of their apoptosis after cultivation with Cnr2(-/-)-M1-MOs. Production of TNF-α in M1-MOs was dependent on CB2 receptor stimulation by anandamide. SIGNIFICANCE: Our data provide novel insights into CB2 receptor-mediated protection of cardiomyocytes during hypoxia and pro-inflammatory stimulation. We show CB2 receptor-dependent effects on migration and function of M1-MOs in interaction with cardiomyocytes, thereby influencing their survival.

The endocannabinoid-CB2 receptor axis protects the ischemic heart at the early stage of cardiomyopathy.

Ischemic heart disease is associated with inflammation, interstitial fibrosis and ventricular dysfunction prior to the development of heart failure. Endocannabinoids and the cannabinoid receptor CB2 have been claimed to be involved, but their potential role in cardioprotection is not well understood. We therefore explored the role of the cannabinoid receptor CB2 during the initial phase of ischemic cardiomyopathy development prior to the onset of ventricular dysfunction or infarction. Wild type and CB2-deficient mice underwent daily brief, repetitive ischemia and reperfusion (I/R) episodes leading to ischemic cardiomyopathy. The relevance of the endocannabinoid-CB2 receptor axis was underscored by the finding that CB2 was upregulated in ischemic wild type cardiomyocytes and that anandamide level was transiently increased during I/R. CB2-deficient mice showed an increased rate of apoptosis, irreversible loss of cardiomyocytes and persistent left ventricular dysfunction 60 days after the injury, whereas wild type mice presented neither morphological nor functional defects. These defects were due to lack of cardiomyocyte protection mechanisms, as CB2-deficient hearts were in contrast to controls unable to induce switch in myosin heavy chain isoforms, antioxidative enzymes and chemokine CCL2 during repetitive I/R. In addition, a prolonged inflammatory response and adverse myocardial remodeling were found in CB2-deficient hearts because of postponed activation of the M2a macrophage subpopulation. Therefore, the endocannabinoid-CB2 receptor axis plays a key role in cardioprotection during the initial phase of ischemic cardiomyopathy development.

Myocardial hypertrophy is associated with inflammation and activation of endocannabinoid system in patients with aortic valve stenosis.

AIMS: Endocannabinoids and their receptors have been associated with cardiac adaptation to injury, inflammation and fibrosis. Experimental studies suggested a role for inflammatory reaction and active remodeling in myocardial hypertrophy, but they have not been shown in human hypertrophy. We investigated the association of the endocannabinoid system with myocardial hypertrophy in patients with aortic stenosis. MAIN METHODS: Myocardial biopsies were collected from patients with aortic stenosis (AS) and atrial myxoma as controls during surgery. Histological and molecular analysis of endocannabinoids and their receptors, inflammatory and remodeling-related cells and mediators was performed. KEY FINDINGS: Myocardial hypertrophy was confirmed with significantly higher cardiomyocyte diameter in AS than in myxoma patients, which had normal cell size. AS patients presented compensated myocardial adaptation to pressure overload. AS patients had significantly higher: concentration of endocannabinoid anandamide, expression of its degrading enzyme FAAH, and of cannabinoid receptor CB2, being predominantly located on cardiomyocytes. Cell density of macrophages and newly recruited leukocytes were higher in AS group, which together with increased expression of chemokines CCL2, CCL4 and CXCL8, and suppression of anti-inflammatory IL-10 indicates persistent inflammatory reaction. We found higher myofibroblast density and stronger tenascin C staining along with mRNA induction of tenascin C and CTGF in AS patients showing active myocardial remodeling. SIGNIFICANCE: Our study shows for the first time activation of the endocannabinoid system and predominant expression of its receptor CB2 on cardiomyocytes being associated with persistent inflammation and active remodeling in hypertrophic myocardium of patients with aortic stenosis.