The Kir2.1E299V mutation increases atrial fibrillation vulnerability while protecting the ventricles against arrhythmias in a mouse model of short QT syndrome type 3.

AIMS: Short QT syndrome type 3 (SQTS3) is a rare arrhythmogenic disease caused by gain-of-function mutations in KCNJ2, the gene coding the inward rectifier potassium channel Kir2.1. We used a multidisciplinary approach and investigated arrhythmogenic mechanisms in an in-vivo model of de-novo mutation Kir2.1E299V identified in a patient presenting an extremely abbreviated QT interval and paroxysmal atrial fibrillation. METHODS AND RESULTS: We used intravenous adeno-associated virus-mediated gene transfer to generate mouse models, and confirmed cardiac-specific expression of Kir2.1WT or Kir2.1E299V. On ECG, the Kir2.1E299V mouse recapitulated the QT interval shortening and the atrial-specific arrhythmia of the patient. The PR interval was also significantly shorter in Kir2.1E299V mice. Patch-clamping showed extremely abbreviated action potentials in both atrial and ventricular Kir2.1E299V cardiomyocytes due to a lack of inward-going rectification and increased IK1 at voltages positive to -80 mV. Relative to Kir2.1WT, atrial Kir2.1E299V cardiomyocytes had a significantly reduced slope conductance at voltages negative to -80 mV. After confirming a higher proportion of heterotetrameric Kir2.x channels containing Kir2.2 subunits in the atria, in-silico 3D simulations predicted an atrial-specific impairment of polyamine block and reduced pore diameter in the Kir2.1E299V-Kir2.2WT channel. In ventricular cardiomyocytes, the mutation increased excitability by shifting INa activation and inactivation in the hyperpolarizing direction, which protected the ventricle against arrhythmia. Moreover, Purkinje myocytes from Kir2.1E299V mice manifested substantially higher INa density than Kir2.1WT, explaining the abbreviation in the PR interval. CONCLUSION: The first in-vivo mouse model of cardiac-specific SQTS3 recapitulates the electrophysiological phenotype of a patient with the Kir2.1E299V mutation. Kir2.1E299V eliminates rectification in both cardiac chambers but protects against ventricular arrhythmias by increasing excitability in both Purkinje-fiber network and ventricles. Consequently, the predominant arrhythmias are supraventricular likely due to the lack of inward rectification and atrial-specific reduced pore diameter of the Kir2.1E299V-Kir2.2WT heterotetramer.

Pre-oxygenation using high-flow nasal oxygen versus tight facemask in trauma patients undergoing emergency anaesthesia.

BACKGROUND: Patients suffering from major traumatic injuries frequently require emergency anaesthesia. Due to often compromised physiology and the time-sensitive management, trauma patients may be more prone to desaturate during induction of anaesthesia. We hypothesised that pre-oxygenation using high-flow nasal oxygen would decrease the risk of desaturation during induction of anaesthesia in trauma patients and the study therefore aimed to compare the frequency of desaturation when pre-oxygenation was performed with high-flow nasal oxygen or a traditional facemask. METHODS: This exploratory, prospective, before-and-after study was conducted at the Karolinska University Hospital, Sweden. Adult (≥18 years of age) patients suffering major traumatic injuries needing emergency anaesthesia were included around the clock. Patients were pre-oxygenated using a tight-fitting facemask during the first nine months of enrollment. High-flow nasal oxygen was then introduced as a method for pre-oxygenation of trauma patients. The primary outcome was the proportion of patients desaturating <93% during induction of anaesthesia, assessed from the start of pre-oxygenation until one minute after intubation. Secondary outcomes included perceived difficulty of pre-oxygenation among anaesthetists (assessed on a scale between 1 and 10) and safety outcomes, such as incidence of regurgitations and intracranial gas (assessed radiologically). RESULTS: Data from 96 patients were analysed. Facemask pre-oxygenation was performed in 66 patients, while 30 patients were pre-oxygenated with high-flow nasal oxygen. The most frequent trauma mechanisms were stabbing injuries (n = 34 (35%)) and fall injuries (n = 21 (22%)). There were no differences in patient characteristics between the groups. Eight (12%) versus three (10%) patients desaturated <93% in the facemask and high-flow nasal oxygen group respectively, OR 0.81 (95% CI 0.20-3.28), p = .76. Anaesthetists assessed pre-oxygenation using high-flow nasal oxygen as easier compared to facemask pre-oxygenation. No patient in any group showed signs of regurgitation. Among patients with facial or skull fractures requiring anaesthesia before radiology was performed, intracranial gas was seen in four (40%) patients pre-oxygenated with a facemask and in no patient pre-oxygenated with HFNO (p = .23). CONCLUSION: In this prospective study investigating trauma patients undergoing emergency anaesthesia, we could not see any difference in the number of patients desaturating when pre-oxygenation was performed with high-flow nasal oxygen compared to a tight-fitting facemask. Pre-oxygenation using high-flow nasal oxygen was assessed as easier compared to facemask pre-oxygenation.

Unconscious bias in speaker introductions at a national vascular surgery meeting: The impact of rank, race and gender.

OBJECTIVES: Unconscious bias can impact manner of speaker introductions in formal academic settings. We examined speaker introductions at the Society of Vascular Surgeons Annual Meeting to determine factors associated with non-professional address. METHODS: We examined speaker introductions from the 2019 SVS Vascular Annual Meeting. Professional title with either full name or last name was considered professional address. Speaker and moderator demographics were collected. Univariate and multivariate logistic regression analyses were performed to identify associations between introduction and speaker and moderator characteristics. RESULTS: 336 talks met inclusion criteria. Both speakers and moderators were more likely to be white (63.4 â€‹% and 65.8 â€‹%,p â€‹= â€‹0.92), man (75.6 â€‹% and 74.4 â€‹%,p â€‹= â€‹0.82) and full professor rank (34.5 â€‹% and 42.3 â€‹%, p â€‹< â€‹0.001). On multivariable regression, non-professional address was associated with speaker rank of trainee (OR 3.13, p â€‹= â€‹0.05) and when moderator was white (OR 2.42, p â€‹= â€‹0.03). CONCLUSIONS: This study emphasizes the potential negative impact of unconscious bias at a national meeting for vascular surgeons and the need to mitigate this effect at the organization level.

MYH10 activation rescues contractile defects in arrhythmogenic cardiomyopathy (ACM).

The most prevalent genetic form of inherited arrhythmogenic cardiomyopathy (ACM) is caused by mutations in desmosomal plakophilin-2 (PKP2). By studying pathogenic deletion mutations in the desmosomal protein PKP2, here we identify a general mechanism by which PKP2 delocalization restricts actomyosin network organization and cardiac sarcomeric contraction in this untreatable disease. Computational modeling of PKP2 variants reveals that the carboxy-terminal (CT) domain is required for N-terminal domain stabilization, which determines PKP2 cortical localization and function. In mutant PKP2 cells the expression of the interacting protein MYH10 rescues actomyosin disorganization. Conversely, dominant-negative MYH10 mutant expression mimics the pathogenic CT-deletion PKP2 mutant causing actin network abnormalities and right ventricle systolic dysfunction. A chemical activator of non-muscle myosins, 4-hydroxyacetophenone (4-HAP), also restores normal contractility. Our findings demonstrate that activation of MYH10 corrects the deleterious effect of PKP2 mutant over systolic cardiac contraction, with potential implications for ACM therapy.

Therapeutic Potential and Predictive Pharmaceutical Modeling of Stilbenes in Cannabis sativa.

Cannabis sativa is a plant used for recreational and therapeutic purposes; however, many of the secondary metabolites in the plant have not been thoroughly investigated. Stilbenes are a class of compounds with demonstrated anti-inflammatory and antioxidant properties and are present in cannabis. Many stilbenes present in cannabis have been investigated for their therapeutic effects. Fourteen stilbenes have been identified to be present in cannabis, all of which are structurally dihydrostilbenoids, with half possessing a prenylated moiety. The stilbenes summarized in this analysis show varying degrees of therapeutic benefits ranging from anti-inflammatory, antiviral, and anti-cancer to antioxidant effects. Many of the identified stilbenes have been researched to a limited extent for potential health benefits. In addition, predictive in silico modeling was performed on the fourteen identified cannabis-derived stilbenes. This modeling provides prospective activity, pharmacokinetic, metabolism, and permeability data, setting the groundwork for further investigation into these poorly characterized compounds.

Outcomes of the Gore® Excluder® Iliac Branch Endoprosthesis Using Self Expanding or Balloon-Expandable Stent Grafts for the Internal Iliac Artery Component.

OBJECTIVE: The GORE® EXCLUDER® Iliac Branch Endoprosthesis (IBE; W.L. Gore & Associates, Flagstaff, Arizona) was developed to be used in combination with a self-expanding stent graft (SESG) for the internal iliac artery (IIA) bridging stent. Balloon-expandable stent grafts (BESGs) are an alternative for the IIA, offering advantages in sizing, device tracking, precision, and lower profile delivery. We compared the performance of SESG and BESG when used as the IIA bridging stent in patients undergoing EVAR with IBE. METHODS: This is a retrospective review of consecutive patients who underwent EVAR with IBE implantation at a single center from October 2016 to May 2021. Anatomic and procedural characteristics were recorded via chart review and computed tomography (CT) postprocessing software (Vitrea® v7.14). Devices were assigned to SESG vs. BESG groups based on the type of device landing into the most distal IIA segment. Analysis was performed per device to account for patients undergoing bilateral IBE. The primary endpoint was IIA patency, and secondary endpoint was IBE-related endoleak. RESULTS: During the study period, 48 IBE devices were implanted in 41 patients (mean age 71.1 years). All IBE devices were implanted in conjunction with an infrarenal endograft. There were 24 devices in each of the self-expanding internal iliac component (SE-IIC) and balloon-expandable internal iliac component (BE-IIC) groups. The BE-IIC group had smaller diameter IIA target vessels (11.6±2.0 mm vs. 8.4±1.7 mm, p<0.001). Mean follow-up was 525 days. Loss of IIA patency occurred in 2 SESG devices (8.33%) at 73 and 180 days postprocedure, and in zero BESG devices, however, this difference was not statistically significant (p=0.16). There was 1 IBE-related endoleak requiring reintervention during the study period. A BESG device required reintervention due to Type 3 endoleak at 284 days. CONCLUSIONS: There were no significant differences in outcomes between SESG and BESG when used for the IIA bridging stent in EVAR with IBE. The BESGs were associated with using 2 IIA bridging stents and were more often deployed in smaller IIA target arteries. Retrospective study design and small sample size may limit the generalizability of our findings. CLINICAL IMPACT: This series compares postoperative and midterm outcomes of self expanding stent grafts and balloon expandable stent grafts (BESG) when used as the internal iliac stent graft as part of a Gore® Excluder® Iliac Branch Endoprosthesis (IBE). With similar outcomes between the two stent-grafts, our series suggests that some of the advantages of BESG, device sizing, tracking, deployment, and profile, may be able to be leveraged without impacting the mid-term performance of the IBE.

Standard Versus Restrictive Transfusion Strategy for Pediatric Cardiac ECLS Patients: Single Center Retrospective Cohort Study.

This retrospective cohort study aimed to compare blood component transfusion before and after the implementation of a restrictive transfusion strategy (RTS) in pediatric cardiac Extracorporeal Life Support (ECLS) patients. The study included children admitted to the pediatric cardiac intensive care unit (PCICU) at the Stollery Children's Hospital who received ECLS between 2012 and 2020. Children on ECLS between 2012 and 2016 were treated with standard transfusion strategy (STS), while those on ECLS between 2016 and 2020 were treated with RTS. During the study, 203 children received ECLS. Daily median (interquartile range [IQR]) packed red blood cell (PRBC) transfusion volume was significantly lower in the RTS group; 26.0 (14.4-41.5) vs. 41.5 (26.6-64.4) ml/kg/day, p value <0.001. The implementation of a RTS led to a median reduction of PRBC transfusion of 14.5 (95% CI: 6.70-21.0) ml/kg/day. Similarly, the RTS group received less platelets: median (IQR) 8.4 (4.50-15.0) vs. 17.5 (9.40-29.0) ml/kg/day, p value <0.001. The implementation of a RTS resulted in a median reduction of platelet transfusion of 9.2 (95% CI: 5.45-13.1) ml/kg/day. The RTS resulted in less median (IQR) fluid accumulation in the first 48 hours: 56.7 (2.30-121.0) vs. 140.4 (33.8-346.2) ml/kg, p value = 0.001. There were no significant differences in mechanical ventilation days, PCICU/hospital days, or survival. The use of RTS resulted in lower blood transfusion volumes, with similar clinical outcomes.

Continuous population-level monitoring of SARS-CoV-2 seroprevalence in a large European metropolitan region.

Effective public health measures against SARS-CoV-2 require granular knowledge of population-level immune responses. We developed a Tripartite Automated Blood Immunoassay (TRABI) to assess the IgG response against three SARS-CoV-2 proteins. We used TRABI for continuous seromonitoring of hospital patients and blood donors (n = 72'250) in the canton of Zurich from December 2019 to December 2020 (pre-vaccine period). We found that antibodies waned with a half-life of 75 days, whereas the cumulative incidence rose from 2.3% in June 2020 to 12.2% in mid-December 2020. A follow-up health survey indicated that about 10% of patients infected with wildtype SARS-CoV-2 sustained some symptoms at least twelve months post COVID-19. Crucially, we found no evidence of a difference in long-term complications between those whose infection was symptomatic and those with asymptomatic acute infection. The cohort of asymptomatic SARS-CoV-2-infected subjects represents a resource for the study of chronic and possibly unexpected sequelae.

Effect of the Length of the Microcycle on the Daily External Load, Fatigue, Sleep Quality, Stress, and Muscle Soreness of Professional Soccer Players: A Full-Season Study.

BACKGROUND: The aim of this study was to analyze the effect of the length of the microcycle (ie, training period from the day after the match to the following match) on the daily external load and perceived wellness of professional soccer players (Spanish LaLiga Smartbank). HYPOTHESIS: The length of the microcycle has a significant effect on the daily external load and perceived wellness. STUDY DESIGN: Longitudinal study. LEVEL OF EVIDENCE: Level 3. METHODS: Data were collected daily during a full season using perceived wellness questionnaires and electronic performance and tracking systems. RESULTS: The length of the microcycle had a significant effect on volume- and intensity-related external load variables. There were differences between short, regular, and long microcycles depending on the day of the microcycle. These differences were observed in all external load variables. However, no significant differences between short, regular, or long microcycles were found on match day for any external load variable, except for high-intensity decelerations. Regarding the perceived wellness, the length of the microcycle had no effect on these variables, and there were no significant interactions between the length and the day of the microcycle. CONCLUSION: The length of the microcycle had a significant effect on volume- and intensity-related external load variables, but no significant effect on perceived wellness was observed. CLINICAL RELEVANCE: These data may help strength and conditioning coaches understand that workload periodization should take this contextual variable into account, especially for external training load. In addition, this study may serve as a guide for practitioners to know the physical requirements of professional soccer players in Spanish LaLiga Smartbank, because the weekly external load profile and perceived wellness have been reported for different lengths of the microcycles. Thus, these data may be used for player load management.

Effect of playing position and microcycle days on the acceleration speed profile of elite football players.

The aim of this study was to analyse the differences in the A-S profile of elite football players induced by playing position and the microcycle day. Players belonged to a second division club in the Spanish La Liga competition. They were classified into five playing positions: central defenders (CD), full backs (FB), midfielders (MF), wide midfielders (WMF) and forwards (FW). Microcycle days were categorised according to the days until matchday (MD, MD-1, MD-2, MD-3, MD-4 and MD-5). Data was collected along six microcycles, including one match per microcycle. The variables analysed were: maximal theoretical acceleration (A0), maximal theoretical speed (S0), maximal acceleration (ACCmax), maximal speed (Smax) and A-S slope (ASslope). Significant differences were found within positions and microcycle day for all variables (p < 0.05). Match day (MD) showed greater values than the training sessions in A0, ACCmax and Smax (p < 0.05). The highest values for variables associated with acceleration capabilities were found in CD on MD, whereas speed variables were higher in WMF. MD-2 showed the lowest values in all variables except for ASslope. Maximal acceleration and sprint abilities are therefore affected by playing position. Wide positions showed the highest speed capacity, and CD presented a likely acceleration profile. Higher values for all variables concerning the microcycle day, were achieved on MD, and were not reproduced during training with the consequent injury risk and performance decrease it takes.

Characterizing endovascular aortic intervention outcomes for nonruptured aortic aneurysms by physician specialty.

BACKGROUND: Evaluate patient outcomes after endovascular aortic interventions performed for nonruptured aortic aneurysms by physician specialties. METHODS: Endovascular aortic repair (EVAR), fenestrated or branched repair (F-BEVAR), and thoracic endovascular aortic repair (TEVAR) procedures were obtained from the Illinois Hospital Association Comparative Health Care and Hospital Data Reporting Services database from 2016 to 2019. Logistic and Poisson regression were used to determine outcomes by patient, physician, and hospital characteristics. RESULTS: A total of 4,935 procedures, 3,666 (74.3%) EVAR, 567 (11.5%) F-BEVAR, and 702 (14.2%) TEVAR were performed by vascular surgeons, interventional radiologists, interventional cardiologists, and cardiac surgeons. Vascular surgeons performed interventions equally between hospital types while interventional radiologists primarily performed interventions in teaching hospitals (68.1%) and interventional cardiologists and cardiac surgeons typically performed interventions in community hospitals (91.8% and 82.1%, respectively; P < .001). No differences in inpatient mortality were noted between specialties. Patients treated by interventional radiologists had increased odds of staying in the hospital ≥8 days (odd ration [OR] 1.95, 95% confidence interval [CI] 1.19-3.19) and patients treated by interventional cardiologists had lower odds of being admitted to the intensive care unit [ICU] (OR 0.42, 95% CI 0.18-0.95). CONCLUSION: Differences in practice patterns among specialties performing endovascular aortic aneurysm repair for nonruptured aneurysms suggest opportunities for collaboration to optimize quality of care.

Changes in Anesthesia Can Reduce Periprocedural Urinary Retention After EVAR.

BACKGROUND: Enhanced recovery after surgery (ERAS) programs provide a streamlined approach for expedient postoperative care of high-volume procedures. Endovascular aortic repair (EVAR) has become standard treatment for abdominal aortic aneurysms and implementation of an early recovery program is warranted. Postoperative urinary retention (POUR) remains a problem lending to longer hospital stays and patient discomfort. We aim to demonstrate the utility of monitored anesthetic care (MAC) plus local anesthesia as a modality to minimize urinary retention following EVAR. METHODS: Single-center retrospective review from January 2017 to March 2020 of all patients undergoing standard elective EVAR under general anesthesia or MAC anesthesia. Local anesthetic at vessel access sites was used in all patients under MAC. Ruptured pathology and female sex were excluded from analysis. Patient characteristics, operative details, prostate measurements, and outcomes were abstracted from the electronic medical record. Urinary retention was defined as any requirement of straight catheterization, urinary catheter replacement, or discharge with urinary catheter. Chi square tests and logistic regression were used to determine predictors associated with POUR and increased hospital length of stay. RESULTS: Among 138 patients who underwent EVAR, eight (5.8%) were excluded due to ruptured pathology. Of the cohort, 113 (86.9%) were male with mean age of 73 years. Excluding female patients, 63 (55.8%) male patients underwent general anesthesia and 50 (44.3%) underwent MAC. Male patients under general anesthesia were more likely to have intra-operative urinary catheter placement when compared to MAC (82.5% vs. 36%, respectively; P < 0.001). POUR was identified in 17 patients (13.1%) of the entire study population with 15 events (88.2%) occurring in males. Excluding patients who were admitted to the ICU, twenty-two (19.5%) male patients stayed past postoperative day (POD) one, of which those who developed POUR were more likely to experience compared to those without POUR (45.6% vs. 9.7%, respectively; P = 0.001). On multivariable analysis, male patients who received MAC had a lower risk of developing POUR (OR 0.09, 95% CI 0.02-0.50). POUR was not associated with elective urinary catheter placement nor with pre-existing conditions such as diabetes, urinary retention, benign prostatic hypertrophy (BPH), or use of BPH medications. Additionally, neither prostate size nor volume was associated with developing POUR among male patients. CONCLUSION: MAC plus local anesthesia is associated with decreased rates of POUR after elective EVAR in male patients. ERAS pathways during elective EVAR interventions should implement MAC plus local anesthesia as an acceptable anesthetic option, where appropriate, in order to reduce urinary retention rates and subsequently decrease hospital length of stay in this patient cohort.

Tbx5 variants disrupt Nav1.5 function differently in patients diagnosed with Brugada or Long QT Syndrome.

AIMS: The transcription factor Tbx5 controls cardiogenesis and drives Scn5a expression in mice. We have identified two variants in TBX5 encoding p. D111Y and p. F206L Tbx5, respectively, in two unrelated patients with structurally normal hearts diagnosed with long QT (LQTS) and Brugada (BrS) syndrome. Here, we characterized the consequences of each variant to unravel the underlying disease mechanisms. METHODS AND RESULTS: We combined clinical analysis with in vivo and in vitro electrophysiological and molecular techniques in human-induced pluripotent stem-cell-derived cardiomyocytes (hiPSC-CMs), HL-1 cells, and cardiomyocytes from mice trans-expressing human wild-type (WT) or mutant proteins. Tbx5 increased transcription of SCN5A encoding cardiac Nav1.5 channels, while repressing CAMK2D and SPTBN4 genes encoding Ca/calmodulin kinase IIδ (CaMKIIδ) and ßIV-spectrin, respectively. These effects significantly increased Na current (INa) in hiPSC-CMs and in cardiomyocytes from mice trans-expressing Tbx5. Consequently, action potential (AP) amplitudes increased and QRS interval narrowed in the mouse electrocardiogram. p. F206L Tbx5 bound to the SCN5A promoter failed to transactivate it, thus precluding the pro-transcriptional effect of WT Tbx5. Therefore, p. F206L markedly decreased INa in hiPSC-CM, HL-1 cells and mouse cardiomyocytes. The INa decrease in p. F206L trans-expressing mice translated into QRS widening and increased flecainide sensitivity. p. D111Y Tbx5 increased SCN5A expression but failed to repress CAMK2D and SPTBN4. The increased CaMKIIδ and ßIV-spectrin significantly augmented the late component of INa (INaL) which, in turn, significantly prolonged AP duration in both hiPSC-CMs and mouse cardiomyocytes. Ranolazine, a selective INaL inhibitor, eliminated the QT and QTc intervals prolongation seen in p. D111Y trans-expressing mice. CONCLUSIONS: In addition to peak INa, Tbx5 critically regulates INaL and the duration of repolarization in human cardiomyocytes. Our original results suggest that TBX5 variants associate with and modulate the intensity of the electrical phenotype in LQTS and BrS patients.

Sustained Elevated Blood Pressure Accelerates Atherosclerosis Development in a Preclinical Model of Disease.

The continuous relationship between blood pressure (BP) and cardiovascular events makes the distinction between elevated BP and hypertension based on arbitrary cut-off values for BP. Even mild BP elevations manifesting as high-normal BP have been associated with cardiovascular risk. We hypothesize that persistent elevated BP increases atherosclerotic plaque development. To evaluate this causal link, we developed a new mouse model of elevated BP based on adeno-associated virus (AAV) gene transfer. We constructed AAV vectors to support transfer of the hRenin and hAngiotensinogen genes. A single injection of AAV-Ren/Ang (1011 total viral particles) induced sustained systolic BP increase (130 ± 20 mmHg, vs. 110 ± 15 mmHg in controls; p = 0.05). In ApoE-/- mice, AAV-induced mild BP elevation caused larger atherosclerotic lesions evaluated by histology (10-fold increase vs. normotensive controls). In this preclinical model, atheroma plaques development was attenuated by BP control with a calcium channel blocker, indicating that a small increase in BP within a physiological range has a substantial impact on plaque development in a preclinical model of atherosclerosis. These data support that non-optimal BP represents a risk for atherosclerosis development. Earlier intervention in elevated BP may prevent or delay morbidity and mortality associated with atherosclerosis.

LAG3 is not expressed in human and murine neurons and does not modulate α-synucleinopathies.

While the initial pathology of Parkinson's disease and other α-synucleinopathies is often confined to circumscribed brain regions, it can spread and progressively affect adjacent and distant brain locales. This process may be controlled by cellular receptors of α-synuclein fibrils, one of which was proposed to be the LAG3 immune checkpoint molecule. Here, we analysed the expression pattern of LAG3 in human and mouse brains. Using a variety of methods and model systems, we found no evidence for LAG3 expression by neurons. While we confirmed that LAG3 interacts with α-synuclein fibrils, the specificity of this interaction appears limited. Moreover, overexpression of LAG3 in cultured human neural cells did not cause any worsening of α-synuclein pathology ex vivo. The overall survival of A53T α-synuclein transgenic mice was unaffected by LAG3 depletion, and the seeded induction of α-synuclein lesions in hippocampal slice cultures was unaffected by LAG3 knockout. These data suggest that the proposed role of LAG3 in the spreading of α-synucleinopathies is not universally valid.

Ipsilateral carotid bypass outcomes in hostile neck anatomy.

OBJECTIVE: To determine differences in outcomes among patients undergoing ipsilateral carotid bypass with hostile or normal neck anatomy. METHODS: Single-center retrospective review of all ipsilateral extracranial carotid bypasses performed between 1998 and 2018. RESULTS: Forty-eight patients underwent ipsilateral carotid bypass from the common carotid artery to either the internal carotid artery or carotid bifurcation during the study period. Seven patients were excluded owing to either a lack of follow-up or missing data. The indications for intervention included infected patches, aneurysmal degeneration, symptomatic and asymptomatic stenosis or restenosis, carotid body tumors, neck malignancy, and trauma. In 25 procedures (61%), there was a hostile neck anatomy defined as a prior history of external beam neck irradiation or neck surgery. Among this group, 12 pectoralis muscle flaps were performed for reconstructive coverage. Conduits included polytetrafluorethylene (n = 21), great saphenous vein (n = 9), superficial femoral artery (n = 7) and arterial homograft (n = 4). All superficial femoral artery conduits were used in the hostile neck group (P = .03). The overall mean time of follow-up was 22 months, with all bypasses remaining patent with no significant clinical stenosis. The 30-day ipsilateral stroke and myocardial infarction rates were 4.88% each, all within the hostile neck group, with no 30-day mortalities for the entire cohort. One-third of the muscle flaps were performed in the setting of infected patches (P = .02) with no significant differences in perioperative outcomes with use. The overall median hospital length of stay was significantly increased in patients receiving muscle flap coverage (3.0 vs 7.0 days; P = .04). CONCLUSIONS: In patients with a complex carotid pathology, ipsilateral carotid bypass is an effective solution for carotid reconstruction. Different conduits should be used depending on the indication. Muscle flap coverage should be considered in hostile settings when primary wound closure is not feasible.

Limb ischemia and bleeding in patients requiring venoarterial extracorporeal membrane oxygenation.

OBJECTIVE: Acute limb ischemia (ALI) and cannulation site bleeding are frequent complications of venoarterial (VA) extracorporeal membrane oxygenation (ECMO) and are associated with worse outcomes. The goals of this study were to assess our rates of ECMO-related ALI and bleeding and to evaluate the efficacy of strategies to prevent them, such as distal perfusion cannula (DPC) and ultrasound-guided cannulation. METHODS: This is a single-center retrospective cohort study of adult patients placed on peripheral VA-ECMO at a tertiary medical center between 2014 and 2018. ALI was defined as new ischemia of the extremity ipsilateral to arterial cannulation. Significant cannulation site bleeding was defined as excessive bleeding requiring intervention (eg, transfusion or reoperation). Univariate analyses were used to identify factors associated with ALI, bleeding, and in-hospital mortality. RESULTS: During the study period, 105 patients were placed on peripheral VA-ECMO (61.3% female; mean age, 54.9 ± 14.8 years). Nearly half (46.6%) had ECMO implantation in an extracorporeal cardiopulmonary resuscitation setting and 37 (44.0%) had a DPC. Average duration of support was 5.6 ± 5.0 days. Overall in-hospital mortality and death on ECMO support were 65.1% and 50%, respectively. ALI occurred in 21 (20%) and cannulation-related bleeding occurred in 24 (22.9%) patients who were treated with a total of 27 procedures, including thromboembolectomy (22.2%), vascular repair (18.5%), and fasciotomy (25.9%). On univariate analysis, cannulation in the operating room (odds ratio [OR], 0.25; 95% confidence interval [CI], 0.08-0.77; P = .02) was associated with decreased risk of ALI, whereas cannulation in the operating room (OR, 2.65; 95% CI, 1.09-6.45; P = .03) and cutdown approach (OR, 4.96; 95% CI, 2.32-10.61; P < .0001) were associated with increased risk of bleeding. Ultrasound-guided placement was associated with decreased risk of bleeding (OR, 0.81; 95% CI, 0.04-0.84; P = .03). DPC was not associated with either ALI (P = .47) or bleeding (P = .06). ALI (OR, 2.68; 95% CI 1.03-6.98; P = .04), age (OR, 1.94; 95% CI, 1.03-3.69; P = .04), and worse baseline heart failure (OR, 2.01; 95% CI, 1.02-3.97; P = .04) were associated with greater risk of in-hospital mortality. Ultrasound-guided cannulation (OR, 0.41; 95% CI, 0.20-0.87; P = .02) was associated with decreased risk of in-hospital mortality. CONCLUSIONS: ALI and significant bleeding are common occurrences after peripheral VA-ECMO cannulation. Whereas DPC placement did not significantly decrease risk of ALI, ultrasound-guided cannulation decreased the risk of bleeding. Cannulation in the operating room is associated with decreased risk of ALI at the expense of increased risk of bleeding. ALI, older age (≥65 years), and worse heart failure increased risk of in-hospital mortality.

A Network of Macrophages Supports Mitochondrial Homeostasis in the Heart.

Cardiomyocytes are subjected to the intense mechanical stress and metabolic demands of the beating heart. It is unclear whether these cells, which are long-lived and rarely renew, manage to preserve homeostasis on their own. While analyzing macrophages lodged within the healthy myocardium, we discovered that they actively took up material, including mitochondria, derived from cardiomyocytes. Cardiomyocytes ejected dysfunctional mitochondria and other cargo in dedicated membranous particles reminiscent of neural exophers, through a process driven by the cardiomyocyte's autophagy machinery that was enhanced during cardiac stress. Depletion of cardiac macrophages or deficiency in the phagocytic receptor Mertk resulted in defective elimination of mitochondria from the myocardial tissue, activation of the inflammasome, impaired autophagy, accumulation of anomalous mitochondria in cardiomyocytes, metabolic alterations, and ventricular dysfunction. Thus, we identify an immune-parenchymal pair in the murine heart that enables transfer of unfit material to preserve metabolic stability and organ function. VIDEO ABSTRACT.

The p.P888L SAP97 polymorphism increases the transient outward current (Ito,f) and abbreviates the action potential duration and the QT interval.

Synapse-Associated Protein 97 (SAP97) is an anchoring protein that in cardiomyocytes targets to the membrane and regulates Na+ and K+ channels. Here we compared the electrophysiological effects of native (WT) and p.P888L SAP97, a common polymorphism. Currents were recorded in cardiomyocytes from mice trans-expressing human WT or p.P888L SAP97 and in Chinese hamster ovary (CHO)-transfected cells. The duration of the action potentials and the QT interval were significantly shorter in p.P888L-SAP97 than in WT-SAP97 mice. Compared to WT, p.P888L SAP97 significantly increased the charge of the Ca-independent transient outward (Ito,f) current in cardiomyocytes and the charge crossing Kv4.3 channels in CHO cells by slowing Kv4.3 inactivation kinetics. Silencing or inhibiting Ca/calmodulin kinase II (CaMKII) abolished the p.P888L-induced Kv4.3 charge increase, which was also precluded in channels (p.S550A Kv4.3) in which the CaMKII-phosphorylation is prevented. Computational protein-protein docking predicted that p.P888L SAP97 is more likely to form a complex with CaMKII than WT. The Na+ current and the current generated by Kv1.5 channels increased similarly in WT-SAP97 and p.P888L-SAP97 cardiomyocytes, while the inward rectifier current increased in WT-SAP97 but not in p.P888L-SAP97 cardiomyocytes. The p.P888L SAP97 polymorphism increases the Ito,f, a CaMKII-dependent effect that may increase the risk of arrhythmias.

The pharmaceutical solvent N-methyl-2-pyrollidone (NMP) attenuates inflammation through Krüppel-like factor 2 activation to reduce atherogenesis.

N-methyl-2-pyrrolidone (NMP) is a versatile water-miscible polar aprotic solvent. It is used as a drug solubilizer and penetration enhancer in human and animal, yet its bioactivity properties remain elusive. Here, we report that NMP is a bioactive anti-inflammatory compound well tolerated in vivo, that shows efficacy in reducing disease in a mouse model of atherosclerosis. Mechanistically, NMP increases the expression of the transcription factor Kruppel-like factor 2 (KLF2). Monocytes and endothelial cells treated with NMP express increased levels of KLF2, produce less pro-inflammatory cytokines and adhesion molecules. We found that NMP attenuates monocyte adhesion to endothelial cells inflamed with tumor necrosis factor alpha (TNF-α) by reducing expression of adhesion molecules. We further show using KLF2 shRNA that the inhibitory effect of NMP on endothelial inflammation and subsequent monocyte adhesion is KLF2 dependent. Enhancing KLF2 expression and activity improves endothelial function, controls multiple genes critical for inflammation, and prevents atherosclerosis. Our findings demonstrate a consistent effect of NMP upon KLF2 activation and inflammation, biological processes central to atherogenesis. Our data suggest that inclusion of bioactive solvent NMP in pharmaceutical compositions to treat inflammatory disorders might be beneficial and safe, in particular to treat diseases of the vascular system, such as atherosclerosis.